JP3638883B2 - Target opposition device - Google Patents

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JP3638883B2
JP3638883B2 JP2001130038A JP2001130038A JP3638883B2 JP 3638883 B2 JP3638883 B2 JP 3638883B2 JP 2001130038 A JP2001130038 A JP 2001130038A JP 2001130038 A JP2001130038 A JP 2001130038A JP 3638883 B2 JP3638883 B2 JP 3638883B2
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target
signal
band
counter
radar
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JP2002323555A (en
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恭史 保科
和広 野村
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Mitsubishi Electric Corp
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Mitsubishi Electric Corp
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Description

【０００１】
【発明の属する技術分野】
この発明は、接近する飛翔体などの目標に対して目標対抗信号を効率的に送信し、目標のレーダ性能を低下させる目標対抗装置に係るものである。
【０００２】
【従来の技術】
図１７は従来の目標対抗装置の構成を示す図である。
図１７において、１０１は送受信空中線（送受信手段）、１０２は広帯域受信器（送受信手段）、１０３は信号処理器（信号分析手段）、１０５は制御器（信号変調手段）、１０６は目標対抗信号変調器（信号変調手段）、１０７は広帯域送信器（送受信手段）である。また、符号Ｘは飛翔体などの目標である。さらに、ｘ（ｔ）は目標Ｘからの目標レーダ信号、ｎ（ｔ）は目標Ｘへ送信する目標対抗信号である。
【０００３】
次に動作について説明する。
目標対抗装置へ接近する目標Ｘからの目標レーダ信号ｘ（ｔ）は、送受信空中線１０１によって受信され、広帯域受信器１０２を経て信号処理器１０３によって目標レーダ信号ｘ（ｔ）の送信帯域δｆＸが検出される。送信帯域δｆＸの検出が信号処理器１０３から制御器１０５へ伝えられると、目標Ｘのレーダ性能を低下させるために、目標対抗信号ｎ（ｔ）が目標Ｘへ送信される。
【０００４】
つまり、制御器１０５から目標対抗信号変調器１０６へ制御信号が出力され、目標対抗信号変調器１０６によって目標対抗信号ｎ（ｔ）の変調が行われる。この目標対抗信号ｎ（ｔ）は、広帯域送信器１０７を経て送受信空中線１０１から目標Ｘへ送信される。このようにして、目標Ｘのレーダ性能を低下させる。
【０００５】
ここで、目標レーダ信号ｘ（ｔ）と目標対抗信号ｎ（ｔ）の周波数特性について説明する。
【０００６】
図１８は従来の目標対抗装置の動作を説明するための図である。横軸は周波数ｆ、縦軸はレベルをそれぞれ表している。
図１８において、｜Ｘ（ｆ）｜，｜Ｎ（ｆ）｜はそれぞれ目標レーダ信号ｘ（ｔ），目標対抗信号ｎ（ｔ）の周波数特性（絶対スペクトル）である。
【０００７】
また、ΔＦＸは目標レーダ信号ｘ（ｔ）の使用可能な周波数帯域（以下目標レーダ帯域とする）、ΔＦＮは目標対抗信号ｎ（ｔ）の送信周波数帯域（以下対抗信号帯域とする）、ΔＦＵ１およびΔＦＵ２は不要送信周波数帯域（以下過剰帯域とする）であり、ΔＦＮ＝ΔＦＵ１＋ΔＦＸ＋ΔＦＵ２の関係になっている。
【０００８】
図１８に示すように、周波数特性｜Ｘ（ｆ）｜の送信帯域δｆＸを含む広い対抗信号帯域ΔＦＮの周波数特性｜Ｎ（ｆ）｜となるように、目標対抗信号変調器１０６によって目標対抗信号ｎ（ｔ）は変調される。この目標対抗信号ｎ（ｔ）の広帯域変調は、周波数ホッピング等による送信帯域δｆＸの変化に対応するためであり、対抗信号帯域ΔＦＮは、目標レーダ信号ｘ（ｔ）の目標レーダ帯域ΔＦＸに加えて過剰帯域ΔＦＵ１，ΔＦＵ２を含んでいる。
【０００９】
【発明が解決しようとする課題】
従来の目標対抗装置は以上のように構成されているので、目標レーダ帯域外の周波数帯域にも目標対抗信号を送信するため、目標対抗信号の送信が非効率になってしまうという課題があった。
【００１０】
これは、従来の目標対抗装置では目標レーダ帯域を検出できないので、対抗信号帯域に過剰帯域を含めなければならず、目標レーダの送信周波数付近を広帯域に覆って変調した目標対抗信号を送信しているからである。
【００１１】
この発明は上記のような課題を解消するためになされたもので、目標からの目標反射信号を利用して目標レーダ帯域を求め、目標レーダ帯域に絞って目標対抗信号を効率的に送信することにより、目標レーダの性能を低下させることが可能な目標対抗装置を構成することを目的とする。
【００１２】
【課題を解決するための手段】
この発明に係る目標対抗装置は、目標レーダ帯域内の送信帯域で送信される目標レーダ信号を目標から受信し、目標対抗信号を上記目標へ送信する送受信手段と、上記目標レーダ信号から上記送信帯域を検出する信号分析手段と、上記目標レーダ帯域および過剰帯域からなる第１対抗信号帯域で上記目標対抗信号を変調する信号変調手段と、この信号変調手段の変調帯域を切替える制御手段とを備えた目標対抗装置において、上記送受信手段は、上記第１対抗信号帯域にて変調された目標対抗信号を送信して上記目標から反射された目標反射信号を受信し、上記信号分析手段は、上記目標反射信号の周波数特性を求め、その信号レベルの変化から上記目標レーダ帯域を求め、上記制御手段は、上記目標レーダ帯域にて上記目標対抗信号が変調されるよう前記信号変調手段の変調帯域を上記第１対抗信号帯域から上記目標レーダ帯域に切替えるものである。
【００１３】
この発明に係る目標対抗装置は、第１対抗信号帯域内で平滑な周波数特性を有する目標対抗信号を信号変調手段が変調し、第１対抗信号帯域の目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を信号分析手段が設定し、レベル閾値以下のレベルを有する帯域を目標反射信号の周波数特性から信号分析手段が求めて目標レーダ帯域とするようにしたものである。
【００１４】
この発明に係る目標対抗装置は、第１対抗信号帯域で変調された目標対抗信号を送受信手段および信号分析手段へ信号変調手段がそれぞれ出力し、目標対抗信号の周波数特性によって目標反射信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたものである。
【００１５】
この発明に係る目標対抗装置は、第１対抗信号帯域のパルス信号を変調して送受信手段および信号分析手段へそれぞれ出力するパルス変調手段を信号変調手段が備え、送受信手段がパルス信号を目標へ送信するとともに、目標で反射したパルス信号である目標反射パルス信号を送受信手段が目標から受信し、パルス信号の周波数特性によって目標反射パルス信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたものである。
【００１６】
この発明に係る目標対抗装置は、第１対抗信号帯域内で平滑な周波数特性を有するＣＷ信号を変調するＣＷ変調手段を信号変調手段が備え、第１対抗信号帯域にわたってＣＷ信号を送受信手段が目標へスィープ送信するとともに、目標で反射したＣＷ信号である目標反射ＣＷ信号を第１対抗信号帯域にわたって送受信手段が目標からスィープ受信し、第１対抗信号帯域の目標反射ＣＷ信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を信号分析手段が設定し、レベル閾値以下のレベルを有する帯域を目標反射ＣＷ信号の周波数特性から信号分析手段が求めて目標レーダ帯域とするようにしたものである。
【００１７】
この発明に係る目標対抗装置は、ＣＷ信号を変調して送受信手段および信号分析手段へそれぞれ出力するＣＷ変調手段を信号変調手段が備え、第１対抗信号帯域内にわたってＣＷ信号を送受信手段が目標へスィープ送信するとともに、目標で反射したＣＷ信号である目標反射ＣＷ信号を第１対抗信号帯域にわたって送受信手段が目標からスィープ受信し、ＣＷ信号の周波数特性によって目標反射ＣＷ信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたものである。
【００１８】
この発明に係る目標対抗装置は、第１対抗信号帯域内で平滑な周波数特性を有し、第１対抗信号帯域未満の狭帯域で狭帯域目標対抗信号を信号変調手段が変調し、第１対抗信号帯域にわたって狭帯域目標対抗信号を送受信手段が目標へスィープ送信するとともに、目標で反射した狭帯域目標対抗信号である狭帯域目標反射信号を第１対抗信号帯域にわたって送受信手段が目標からスィープ受信し、狭帯域目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を信号分析手段が設定し、レベル閾値以下のレベルを有する帯域を狭帯域目標反射信号の周波数特性から信号分析手段が求めて目標レーダ帯域とするようにしたものである。
【００１９】
この発明に係る目標対抗装置は、第１対抗信号帯域内で平滑な周波数特性を有し、第１対抗信号帯域未満の狭帯域で狭帯域目標対抗信号を信号変調手段が変調して送受信手段および信号分析手段へそれぞれ出力し、第１対抗信号帯域にわたって狭帯域目標対抗信号を送受信手段が目標へスィープ送信するとともに、目標で反射した狭帯域目標対抗信号である狭帯域目標反射信号を第１対抗信号帯域にわたって送受信手段が目標からスィープ受信し、狭帯域目標対抗信号の周波数特性によって狭帯域目標反射信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたものである。
【００２０】
この発明に係る目標対抗装置は、目標レーダ信号の送信帯域と第１対抗信号帯域とを一致させて目標対抗信号を信号変調手段が変調するとともに、第１対抗信号帯域を送信帯域から順次広げて目標対抗信号を信号変調手段が変調し、第１対抗信号帯域の目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を信号分析手段が設定し、レベル閾値以上のレベルを有する帯域を目標反射信号の周波数特性から信号分析手段が求めて目標レーダ帯域とするようにしたものである。
【００２１】
この発明に係る目標対抗装置は、目標レーダ信号の送信帯域と第１対抗信号帯域とを一致させて目標対抗信号を信号変調手段が変調するとともに、第１対抗信号帯域を送信帯域から順次広げて目標対抗信号を変調して送受信手段および信号分析手段へ信号変調手段がそれぞれ出力し、目標対抗信号の周波数特性によって目標反射信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたものである。
【００２２】
この発明に係る目標対抗装置は、目標反射信号に含まれるドップラ周波数の変化を検出し、ドップラ周波数の変化に応じて対抗効果を判定する対抗効果判定処理手段と、対抗効果判定処理手段で判定された対抗効果によって起動され、異なる対抗装置を新たに投入する対抗装置投入手段とを備えるようにしたものである。
【００２３】
この発明に係る目標対抗装置は、ドップラ周波数が低い方に変化した場合に対抗効果判定処理手段が対抗効果を高いと判定するようにしたものである。
【００２４】
この発明に係る目標対抗装置は、ドップラ周波数が変化していない場合に対抗効果判定処理手段が対抗効果を低いと判定するようにしたものである。
【００２５】
この発明に係る目標対抗装置は、信号分析手段で検出された目標レーダ帯域を与えられ、目標レーダ帯域外においてレーダ信号を目標へ送信するレーダ装置を備えるようにしたものである。
【００２６】
【発明の実施の形態】
以下、この発明の実施の一形態を説明する。
実施の形態１．
図１はこの発明の実施の形態１による目標対抗装置の構成を示す図である。
図１において、１は送受信空中線（送受信手段）、２は広帯域受信器（送受信手段）、３は信号処理器（信号分析手段）、４は周波数分析器（信号分析手段）、５は制御器（信号変調手段）、６は目標対抗信号変調器（信号変調手段）、７は広帯域送信器（送受信手段）である。また、符号Ｘは飛翔体などの目標である。さらに、ｘ（ｔ）は目標Ｘから送信される目標レーダ信号、ｎ（ｔ）は目標Ｘへ送信する目標対抗信号、ｒ（ｔ）は目標Ｘから受信する目標反射信号である。
【００２７】
次に動作について説明する。
目標対抗装置へ接近する目標Ｘからの目標レーダ信号ｘ（ｔ）は、送受信空中線１によって受信され、広帯域受信器２を経て、信号処理器３・周波数分析器４へ入力され、目標レーダ信号ｘ（ｔ）の送信帯域δｆＸが検出される。送信帯域δｆＸの検出が信号処理器３・周波数分析器４から制御器５へ伝えられると、目標Ｘのレーダ性能を低下させるために、目標対抗信号ｎ（ｔ）が目標Ｘへ送信される。
【００２８】
つまり、制御器５から目標対抗信号変調器６へ制御信号が出力され、第１対抗信号帯域ΔＦＮ１の目標対抗信号ｎ（ｔ）の変調が目標対抗信号変調器６によって行われる。目標対抗信号ｎ（ｔ）は、広帯域送信器７を経て送受信空中線１から目標Ｘへ送信される。
【００２９】
この時点での目標対抗信号ｎ（ｔ）の変調帯域は、従来と同様に、目標レーダ信号ｘ（ｔ）の目標レーダ帯域ΔＦＸに加えて過剰帯域ΔＦＵ１，ΔＦＵ２を含む第１対抗信号帯域ΔＦＮ１であり、また目標対抗信号ｎ（ｔ）の周波数特性は、第１対抗信号帯域ΔＦＮ１内にわたって平滑になっている。
【００３０】
送信された目標対抗信号ｎ（ｔ）は目標Ｘで反射し、目標反射信号ｒ（ｔ）として送受信空中線１によって受信される。この目標反射信号ｒ（ｔ）は、広帯域受信器２，信号処理器３を経て周波数分析器４へ入力される。
【００３１】
目標Ｘのレーダ開口面上では、目標レーダ信号ｘ（ｔ）の使用可能な周波数帯域である目標レーダ帯域ΔＦＸ内の電磁波が共振を起こし、その一部が吸収される。送受信空中線１から目標Ｘへ送信した広帯域の目標対抗信号ｎ（ｔ）についても同様であり、第１対抗信号帯域ΔＦＮ１のうち、目標レーダ帯域ΔＦＸに相当する一部の目標対抗信号ｎ（ｔ）が共振を起こして目標Ｘのレーダ開口面で吸収され、その残りが目標反射信号ｒ（ｔ）として目標Ｘから反射される。
【００３２】
つまり、第１対抗信号帯域ΔＦＮ１の目標反射信号ｒ（ｔ）から、目標Ｘのレーダ開口面で吸収された帯域を検出すれば、目標Ｘのレーダ開口面の共振特性が把握され、目標レーダ帯域ΔＦＸが求められることが分かる。
【００３３】
例えば、送受信空中線１〜目標Ｘ間の信号伝播時間、損失をそれぞれＴ，Ｋとし、目標対抗信号ｎ（ｔ）のフーリエ変換結果をＮ（ｆ），目標Ｘのレーダ開口面のインパルス応答をｇ（ｔ），このインパルス応答ｇ（ｔ）のフーリエ変換結果をＧ（ｆ）とすると、目標反射信号ｒ（ｔ）とそのフーリエ変換結果Ｒ（ｆ）とはそれぞれ式（１），式（２）のようになる。
【００３４】
ｒ（ｔ）＝Ｋｇ（ｔ）＊ｎ（ｔ−Ｔ） （１）
（ただし＊は畳込を表す演算子）
【００３５】
Ｒ（ｆ）＝ＫＧ（ｆ）Ｎ（ｆ）ｅｘｐ（−ｊ２πｆＴ） （２）
（ただしｅｘｐは指数関数、ｊは虚数、πは円周率）
【００３６】
そして、この実施の形態１では、第１対抗信号帯域ΔＦＮ１にわたって平滑な周波数特性、つまり｜Ｎ（ｆ）｜＝Ａ（ただしｆ１＜ｆ＜ｆ２，ΔＦＮ＝ｆ２−ｆ１，Ａは非零の定数）となるように、目標対抗信号変調器６によって目標対抗信号ｎ（ｔ）を変調しているので、目標反射信号ｒ（ｔ）の周波数特性（絶対スペクトル）｜Ｒ（ｆ）｜は式（３）のようになる。
【００３７】
｜Ｒ（ｆ）｜＝Ｋ｜Ｇ（ｆ）｜｜Ｎ（ｆ）｜＝ＫＡ｜Ｇ（ｆ）｜ （３）
（ただし｜｜は絶対値記号）
【００３８】
このように、目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜から、目標Ｘのレーダ開口面の周波数特性｜Ｇ（ｆ）｜が得られ、この｜Ｇ（ｆ）｜で見受けられる目標Ｘのレーダ開口面の共振特性から目標レーダ帯域ΔＦＸを判断することができる。
【００３９】
具体的な処理について次に説明する。
図２はこの発明の実施の形態１による目標対抗装置の動作を説明するための図である。横軸は周波数、縦軸はレベルをそれぞれ表している。
図２において、｜Ｘ（ｆ）｜，｜Ｎ（ｆ）｜，｜Ｒ（ｆ）｜はそれぞれ目標レーダ信号ｘ（ｔ），目標対抗信号ｎ（ｔ），目標反射信号ｒ（ｔ）の周波数特性（絶対スペクトル）である。
【００４０】
図２（ａ）に示すように、目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜が周波数分析器４によって求められる。前述したように、周波数特性｜Ｒ（ｆ）｜は、目標Ｘの目標レーダ帯域ΔＦＸに相当する電磁波が吸収されて、目標対抗信号ｎ（ｔ）の平滑なレベルが保たれていない。
【００４１】
すなわち、図２（ａ）の周波数特性｜Ｒ（ｆ）｜は、目標レーダ帯域ΔＦＸ外の帯域ではそのレベルがＲＭＡＸ（＝ＫＡ）になっているが、目標レーダ帯域ΔＦＸに相当する帯域では、レーダ開口面の共振特性によってレベルがＲＭＡＸからＲＭＩＮ（ＲＭＩＮ＜ＲＭＡＸ）へ低下している。
【００４２】
周波数分析器４では、周波数ｆ１から周波数ｆ２までの第１対抗信号帯域ΔＦＮ１にわたって、周波数特性｜Ｒ（ｆ）｜のレベル平均値Ａｖｇが算出され（ＲＭＩＮ＜Ａｖｇ＜ＲＭＡＸ）、この平均値Ａｖｇより一定値だけ低いレベル閾値Ｔｈが設定される（ＲＭＩＮ＜Ｔｈ≦Ａｖｇ＜ＲＭＡＸ）。そして、レベル閾値Ｔｈ以下となる領域、つまりＲＭＩＮのレベルとなる帯域が周波数特性｜Ｒ（ｆ）｜から周波数分析器４によって求められる。このレベル閾値Ｔｈ以下の帯域が目標Ｘのレーダ開口面の共振帯域であり、目標レーダ帯域ΔＦＸとして周波数分析器４から制御器５へ出力される。
【００４３】
目標反射信号ｒ（ｔ）から目標レーダ帯域ΔＦＸが検出されると、目標対抗信号ｎ（ｔ）の変調帯域が第１対抗信号帯域ΔＦＮ１から第２対抗信号帯域ΔＦＮ２へ切替えられるように、制御器５から目標対抗信号変調器６へ制御信号を出力する。ここで、第２対抗信号帯域ΔＦＮ２は目標レーダ帯域ΔＦＸと一致する帯域である。第２対抗信号帯域ΔＦＮ２の目標対抗信号ｎ（ｔ）（図２（ｂ））は、目標対抗信号変調器６によって変調され、広帯域送信器７を経て送受信空中線１から目標Ｘへ送信される。
【００４４】
この時点での目標対抗信号ｎ（ｔ）の変調帯域は、目標レーダ帯域ΔＦＸと一致する第２対抗信号帯域ΔＦＮ２であり、目標レーダ帯域ΔＦＸのみに対して送信されるので、従来で課題となっていた過剰帯域ΔＦＵ１，ΔＦＵ２への無駄な送信を行なうことなく、目標レーダ帯域ΔＦＸだけに対して効率的な送信を行うことができ、目標Ｘのレーダ性能を低下させることが可能となる。
【００４５】
以上のように、この実施の形態１によれば、第１対抗信号帯域ΔＦＮ１の目標対抗信号ｎ（ｔ）が目標Ｘで反射した目標反射信号ｒ（ｔ）を送受信空中線１・広帯域受信器２が受信し、第１対抗信号帯域ΔＦＮ１の目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜から目標レーダ帯域ΔＦＸを信号処理器３・周波数分析器４が求め、目標レーダ帯域ΔＦＸを第２対抗信号帯域ΔＦＮ２として目標対抗信号ｎ（ｔ）を制御器５・目標対抗信号変調器６が変調するようにしたので、従来と異なり、過剰帯域ΔＦＵ１，ΔＦＵ２へ無駄な送信を行なうことなく、目標レーダ帯域ΔＦＸだけに対して効率的な目標対抗信号ｎ（ｔ）の送信を行うことができ、目標Ｘのレーダ性能を低下させることができるという効果が得られる。
【００４６】
また、この実施の形態１によれば、第１対抗信号帯域ΔＦＮ１内で平滑な周波数特性｜Ｎ（ｆ）｜を有する目標対抗信号ｎ（ｔ）を制御器５・目標対抗信号変調器６が変調し、第１対抗信号帯域ΔＦＮ１の目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜から算出されるレベル平均値Ａｖｇより一定値だけ低いレベル閾値Ｔｈを信号処理器３・周波数分析器４が設定し、レベル閾値Ｔｈ以下のレベルを有する帯域を目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜から信号処理器３・周波数分析器４が求めて目標レーダ帯域ΔＦＸとするようにしたので、目標Ｘのレーダ開口面における共振現象を利用して、目標レーダ帯域ΔＦＸを求めることができるという効果が得られる。
【００４７】
実施の形態２．
この実施の形態２では、目標対抗信号ｎ（ｔ）と目標反射信号ｒ（ｔ）との両信号を利用して、目標レーダ帯域ΔＦＸを求める手法について説明する。
【００４８】
図３はこの発明の実施の形態２による目標対抗装置の構成を示す図である。図１と同一符号は同一または相当する構成である。
図３において、８は目標対抗信号変調器６が変調した目標対抗信号ｎ（ｔ）を周波数分析器４へ入力する分岐経路（信号変調手段）である。
【００４９】
図４はこの発明の実施の形態２による目標対抗装置の動作を説明するための図である。横軸は周波数、縦軸はレベルをそれぞれ表している。
【００５０】
実施の形態１と同様に、この実施の形態２の目標対抗装置は、目標Ｘからの目標レーダ信号ｘ（ｔ）を受信すると、目標対抗信号ｎ（ｔ）を送受信空中線１から送信して、送受信空中線１で受信した目標反射信号ｒ（ｔ）を周波数分析器４へ入力する。
【００５１】
そして、この実施の形態２では、分岐経路８を設けて目標対抗信号ｎ（ｔ）を目標反射信号ｒ（ｔ）とともに周波数分析器４へ入力している。周波数分析器４は、図４（ａ）に示す目標対抗信号ｎ（ｔ）の周波数特性｜Ｎ（ｆ）｜と、図４（ｂ）に示す目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜を正規化したものとから目標レーダ帯域ΔＦＸを求める。
【００５２】
目標反射信号ｒ（ｔ）の正規化周波数特性｜Ｒ（ｆ）｜／Ｋは式（３）から次式のようになる。
【００５３】
｜Ｒ（ｆ）｜／Ｋ＝｜Ｇ（ｆ）｜｜Ｎ（ｆ）｜ （４）
【００５４】
このとき、周波数分析器４は、分岐経路８からの目標対抗信号ｎ（ｔ）から算出される周波数特性｜Ｎ（ｆ）｜によって式（４）を除算（デシベル表示では減算）し、式（５）の結果を得る。
【００５５】
［｜Ｒ（ｆ）｜／Ｋ］／｜Ｎ（ｆ）｜＝｜Ｇ（ｆ）｜ （５）
【００５６】
このように、目標反射信号ｒ（ｔ）の正規化周波数特性｜Ｒ（ｆ）｜／Ｋを目標対抗信号ｎ（ｔ）の周波数特性｜Ｎ（ｆ）｜で除算することにより、目標Ｘのレーダ開口面の周波数特性｜Ｇ（ｆ）｜が得られ、以下実施の形態１と同様に、レベル閾値Ｔｈを周波数特性｜Ｇ（ｆ）｜に用いることで（図４（ｂ））、レベルＲＭＩＮとなる目標レーダ帯域ΔＦＸが求められる（図４（ｃ））。
【００５７】
特にこの実施の形態２の手法によれば、目標対抗信号ｎ（ｔ）の周波数特性｜Ｎ（ｆ）｜で平滑なレベルを実現する必要がなく、目標レーダ帯域ΔＦＸを求めることが可能となる。
【００５８】
以上のように、この実施の形態２によれば、第１対抗信号帯域ΔＦＮ１で変調された目標対抗信号ｎ（ｔ）を送受信空中線１・広帯域送信器７および周波数分析器４へ目標対抗信号変調器６がそれぞれ出力し、目標対抗信号ｎ（ｔ）の周波数特性｜Ｎ（ｆ）｜によって目標反射信号ｒ（ｔ）の正規化周波数特性｜Ｒ（ｆ）｜／Ｋを信号処理器３・周波数分析器４が除算して目標レーダ帯域ΔＦＸを求めるようにしたので、第１対抗信号帯域ΔＦＮ１において平滑な周波数特性を持たない目標対抗信号ｎ（ｔ）の場合でも、目標レーダ帯域ΔＦＸを求めることができるという効果が得られる。
【００５９】
実施の形態３．
目標対抗信号ｎ（ｔ）の代わりに、パルス信号ｐ（ｔ）を目標Ｘへ送信し、このパルス信号ｐ（ｔ）とその目標反射パルス信号ｒｐ（ｔ）とを利用して、目標レーダ帯域ΔＦＸを求めても良い。
【００６０】
図５はこの発明の実施の形態３による目標対抗装置の構成を示す図である。図１，３と同一符号は同一または相当する構成である。
図５において、９は目標対抗信号変調器６と並列に設けられたパルス変調器（信号変調手段、パルス変調手段）、１０Ａ，１０Ｂはそれぞれ切替器（信号変調手段）である。また、ｐ（ｔ），ｒｐ（ｔ）はそれぞれ目標Ｘへ送信するパルス信号、目標Ｘから受信する目標反射パルス信号である。
【００６１】
図５において、極めてパルス幅の小さい広帯域（第１対抗信号帯域ΔＦＮ１相当）のパルス信号ｐ（ｔ）の変調がパルス変調器９によって行われる。このパルス信号ｐ（ｔ）は、広帯域送信器７を経て送受信空中線１から目標Ｘへ送信される。
【００６２】
パルス信号ｐ（ｔ）は目標Ｘで反射され、目標反射パルス信号ｒｐ（ｔ）として送受信空中線１に受信され、広帯域受信器２，信号処理器３を経て、周波数分析器４に入力される。実施の形態２と同様に、周波数分析器４には、目標Ｘへ送信されるパルス信号ｐ（ｔ）と、目標Ｘから受信される目標反射パルス信号ｒｐ（ｔ）とが与えられる。
【００６３】
図６はこの発明の実施の形態３による目標対抗装置の動作を説明するための図である。横軸は周波数、縦軸はレベルをそれぞれ表している。
図６において、｜Ｘ（ｆ）｜，｜Ｐ（ｆ）｜，｜ＲＰ（ｆ）｜はそれぞれ目標レーダ信号ｘ（ｔ），パルス信号ｐ（ｔ），目標反射パルス信号ｒｐ（ｔ）の周波数特性（絶対スペクトル）である。
【００６４】
周波数分析器４では、パルス信号ｐ（ｔ）の周波数特性｜Ｐ（ｆ）｜（図６（ａ））によって目標反射パルス信号ｒｐ（ｔ）の正規化周波数特性｜ＲＰ（ｆ）｜／Ｋ（図６（ｂ））が除算（デシベルで減算）され、図６（ｃ）の目標レーダ帯域ΔＦＸが得られる。
【００６５】
目標レーダ帯域ΔＦＸが求められると、図５では、切替器１０Ａ，１０Ｂが切替わってパルス変調器９が切り離され、代わりに目標対抗信号変調器６が広帯域送信器７および制御器５に接続される。以下、実施の形態１，２と同様に、第２対抗信号帯域ΔＦＮ２（＝ΔＦＸ）の目標対抗信号ｎ（ｔ）が目標対抗信号変調器６で変調され、送受信空中線１から目標Ｘへ送信される。
【００６６】
このように、パルス信号ｐ（ｔ）１波の送受信が行われる瞬時の間に目標レーダ帯域ΔＦＸを求めることが可能となり、目標Ｘに対する対抗を速く行なうことができる。
【００６７】
以上のように、この実施の形態３によれば、第１対抗信号帯域ΔＦＮ１のパルス信号ｐ（ｔ）を変調して送受信空中線１・広帯域送信器７および周波数分析器４へそれぞれ出力するパルス変調器９を目標対抗信号変調器６と切替器１０Ａ，１０Ｂによって並列に備え、送受信空中線１がパルス信号ｐ（ｔ）を目標Ｘへ送信するとともに、目標Ｘで反射したパルス信号ｐ（ｔ）である目標反射パルス信号ｒｐ（ｔ）を送受信空中線１・広帯域受信器２が目標Ｘから受信し、パルス信号ｐ（ｔ）の周波数特性｜Ｒ（ｆ）｜によって目標反射パルス信号ｒｐ（ｔ）の正規化周波数特性｜ＲＰ（ｆ）｜／Ｋを周波数分析器４が除算して目標レーダ帯域ΔＦＸを求めるようにしたので、パルス信号ｐ（ｔ）１波の送受信が行われる瞬時の間に目標レーダ帯域ΔＦＸを求めることが可能となり、第２対抗信号帯域ΔＦＮ２の目標対抗信号ｎ（ｔ）を目標Ｘへ速く送信できるという効果が得られる。
【００６８】
実施の形態４．
目標対抗信号ｎ（ｔ）の代わりに、チャープ変調のように広帯域にわたって短時間で高速スイープするＣＷ（英：Ｃｏｎｔｉｎｕｏｕｓ Ｗａｖｅ，連続波）信号ｃ（ｔ）を目標Ｘへ送信し、その目標反射ＣＷ信号ｒｃ（ｔ）を利用して、目標レーダ帯域ΔＦＸを求めても良い。
【００６９】
図７はこの発明の実施の形態４による目標対抗装置の構成を示す図である。図１，５と同一符号は同一または相当する構成である。
図７において、１１は切替器１０Ａ，１０Ｂによって目標対抗信号変調器６と並列に設けられたＣＷ変調器（信号変調手段、ＣＷ変調手段）、１２は局部信号発振器（送受信手段）、１３Ａ，１３Ｂはそれぞれ乗算器（送受信手段）である。
【００７０】
図７に示すように、まずＣＷ変調器１１によってＣＷ変調が行われＣＷ信号ｃ（ｔ）が生成される。ここでは、ＣＷ信号ｃ（ｔ）は第１対抗信号帯域ΔＦＮ１において平滑な特性を持つものとする。このＣＷ信号ｃ（ｔ）は、広帯域送信器７を経て乗算器１３Ａへ入力される。乗算器１３Ａでは、局部信号発振器１２から入力されるスィープ信号とＣＷ信号ｃ（ｔ）とがミキシングされる。
【００７１】
局部信号発振器１２からのスィープ信号は、目標レーダ帯域を含む広い周波数帯域（第１対抗信号帯域ΔＦＮ１相当）にわたってその周波数が変化するので、乗算器１３Ａから出力されて送受信空中線１から目標Ｘへ送信されるＣＷ信号ｃ（ｔ）は、チャープ変調のように短時間の間に送受信空中線１から目標Ｘへスイープ送信される。
【００７２】
ＣＷ信号ｃ（ｔ）は目標Ｘで反射され、目標反射ＣＷ信号ｒｃ（ｔ）として送受信空中線１で受信される。この目標反射ＣＷ信号ｒｃ（ｔ）は乗算器１３Ｂへ入力され、局部信号発振器１２からのスィープ信号とのミキシングのよってスィープ受信される。その後に目標反射ＣＷ信号ｒｃ（ｔ）は、広帯域受信器２，信号処理器３を経て周波数分析器４へ入力される。
【００７３】
図８はこの発明の実施の形態４による目標対抗装置の動作を説明するための図である。横軸は周波数、縦軸はレベルをそれぞれ表している。
図８において、｜Ｘ（ｆ）｜，｜Ｎ（ｆ）｜，｜ＲＣ（ｆ）｜はそれぞれ目標レーダ信号ｘ（ｔ），目標対抗信号ｎ（ｔ），目標反射ＣＷ信号ｒｃ（ｔ）の周波数特性（絶対スペクトル）である。
【００７４】
周波数分析器４では、局部信号発振器１２からのスィープ信号の周波数が参照され、実施の形態１と同様に、目標反射ＣＷ信号ｒｃ（ｔ）の周波数特性｜ＲＣ（ｆ）｜が求められる（図８（ａ））。そして、周波数特性｜ＲＣ（ｆ）｜のレベル平均値Ａｖｇより一定値低いレベルに設定されたレベル閾値Ｔｈ以下となる帯域を求めることにより、目標レーダ帯域ΔＦＸを求めることが可能となる。
【００７５】
このようにすることで、ＣＷ信号ｃ（ｔ）をスイープさせる短時間の間に目標レーダ帯域ΔＦＸを求めることが可能となる。
【００７６】
以後の動作は、実施の形態３と同様に、切替器１０Ａ，１０Ｂによって目標対抗信号変調器６がＣＷ変調器１１に代わって制御器５，広帯域送信器７に接続され、第２対抗信号帯域ΔＦＮ２（＝ΔＦＸ）の帯域で目標対抗信号変調器６に変調された目標対抗信号ｎ（ｔ）（図８（ｂ））が広帯域送信器７，送受信空中線１を経て目標Ｘへ送信される。第２対抗信号帯域ΔＦＮ２の目標対抗信号ｎ（ｔ）が送信される際には、局部信号発振器１２からはスィープ信号が出力されず、乗算器１３Ａ，１３Ｂはスルー状態になる。
【００７７】
なお、スイープさせる第１対抗信号帯域ΔＦＮ１相当の帯域において、平滑な周波数特性をＣＷ信号ｃ（ｔ）で実現できない場合には、実施の形態２と同様に、目標Ｘへ送信されるＣＷ信号ｃ（ｔ）の周波数特性｜Ｃ（ｆ）｜によって目標Ｘから受信される目標反射ＣＷ信号ｒｃ（ｔ）の正規化周波数特性｜ＲＣ（ｆ）｜／Ｋを除算して、目標レーダ帯域ΔＦＸを求めても良い。
【００７８】
以上のように、この実施の形態４によれば、第１対抗信号帯域ΔＦＮ１内で平滑な周波数特性を有するＣＷ信号ｃ（ｔ）を変調するＣＷ変調器１１を切替器１０Ａ，１０Ｂによって目標対抗信号変調器６と並列に備え、第１対抗信号帯域ΔＦＮ１にわたってＣＷ信号ｃ（ｔ）を広帯域送信器７・局部信号発振器１２・乗算器１３Ａ・送受信空中線１が目標Ｘへスィープ送信するとともに、目標Ｘで反射したＣＷ信号ｃ（ｔ）である目標反射ＣＷ信号ｒｃ（ｔ）を第１対抗信号帯域ΔＦＮ１にわたって送受信空中線１・局部信号発振器１２・乗算器１３Ｂ・広帯域受信器２が目標Ｘからスィープ受信し、第１対抗信号帯域ΔＦＮ１の目標反射ＣＷ信号ｒｃ（ｔ）の周波数特性｜ＲＣ（ｆ）｜から算出されるレベル平均値Ａｖｇより一定値だけ低いレベル閾値Ｔｈを周波数分析器４が設定し、レベル閾値Ｔｈ以下のレベルを有する帯域を目標反射ＣＷ信号ｒｃ（ｔ）の周波数特性｜ＲＣ（ｆ）｜から周波数分析器４が求めて目標レーダ帯域ΔＦＸとするようにしたので、短時間の間に目標レーダ帯域ΔＦＸを求めることができるという効果が得られる。
【００７９】
以上のように、この実施の形態４によれば、ＣＷ信号ｃ（ｔ）を変調して広帯域送信器７・局部信号発振器１２・乗算器１３Ａ・送受信空中線１および周波数分析器４へそれぞれ出力するＣＷ変調器１１を切替器１０Ａ，１０Ｂによって目標対抗信号変調器６と並列に備え、第１対抗信号帯域ΔＦＮ１内にわたってＣＷ信号ｃ（ｔ）を広帯域送信器７・局部信号発振器１２・乗算器１３Ａ・送受信空中線１が目標Ｘへスィープ送信するとともに、目標Ｘで反射したＣＷ信号ｃ（ｔ）である目標反射ＣＷ信号ｒｃ（ｔ）を第１対抗信号帯域ΔＦＮ１にわたって送受信空中線１・局部信号発振器１２・乗算器１３Ｂ・広帯域受信器２が目標Ｘからスィープ受信し、ＣＷ信号ｃ（ｔ）の周波数特性｜Ｃ（ｆ）｜によって目標反射ＣＷ信号ｒｃ（ｔ）の正規化周波数特性｜ＲＣ（ｆ）｜／Ｋを周波数分析器４が除算して目標レーダ帯域ΔＦＸを求めるようにしたので、第１対抗信号帯域ΔＦＮ１において平滑な周波数特性を持たないＣＷ信号ｃ（ｔ）の場合でも、短時間の間に目標レーダ帯域ΔＦＸを求めることができるという効果が得られる。
【００８０】
実施の形態５．
第１対抗信号帯域ΔＦＮ１の目標対抗信号ｎ（ｔ）の代わりに、狭帯域（第１対抗信号帯域ΔＦＮ１未満）の目標対抗信号ｎ’（ｔ）を第１対抗信号帯域ΔＦＮ１にわたってスイープ送信し、その目標反射信号ｒ’（ｔ）を利用して目標レーダ帯域ΔＦＸを求めても良い。
【００８１】
図９はこの発明の実施の形態５による目標対抗装置の構成を示す図である。図１，７と同一符号は同一または相当する構成である。
図９において、１４は狭帯域受信器（送受信手段）、１５は狭帯域送信器（送受信手段）である。また、ｎ’（ｔ）は狭帯域目標対抗信号、ｒ’（ｔ）は狭帯域目標反射信号である。
【００８２】
図９に示すように、目標対抗信号変調器６によって狭帯域目標対抗信号ｎ’（ｔ）の変調が行われる。この狭帯域目標対抗信号ｎ’（ｔ）はスイープさせる周波数帯域において平滑な特性を持つものとする。狭帯域目標対抗信号ｎ’（ｔ）は狭帯域送信器１５を経て乗算器１３Ａへ入力し、実施の形態４と同様に、局部信号発振器１２からのスィープ信号と乗算器１３Ａによってミキシングされ、目標レーダ帯域ΔＦＸを含む広い周波数帯域（第１対抗信号帯域ΔＦＮ１相当）にわたって、送受信空中線１から目標Ｘへスイープ送信される。
【００８３】
狭帯域目標対抗信号ｎ’（ｔ）は目標Ｘで反射され、実施の形態４と同様に、狭帯域目標対抗信号ｎ’（ｔ）として目標Ｘから送受信空中線１でスィープ受信される。スィープ受信された狭帯域目標対抗信号ｎ’（ｔ）は、狭帯域受信器１４，信号処理器３を経て、周波数分析器４へ入力される。
【００８４】
図１０はこの発明の実施の形態５による目標対抗装置の動作を説明するための図である。横軸は周波数、縦軸はレベルをそれぞれ表している。
図１０において、｜Ｘ（ｆ）｜，｜Ｎ’（ｆ）｜，｜Ｒ’（ｆ）｜はそれぞれ目標レーダ信号ｘ（ｔ），狭帯域目標対抗信号ｎ’（ｔ），狭帯域目標反射信号ｒ’（ｔ）の周波数特性（絶対スペクトル）である。
【００８５】
周波数分析器４では、実施の形態１，４と同様に、狭帯域目標反射信号ｒ’（ｔ）の周波数特性｜Ｒ’（ｆ）｜が求められ、図１０（ａ）に示すように、周波数特性｜Ｒ’（ｆ）｜のレベル平均値Ａｖｇより一定値低いレベルに設定されたレベル閾値Ｔｈ以下となる帯域を求めることにより、目標レーダ帯域ΔＦＸを求めることが可能となる。
【００８６】
このようにすることで、狭帯域受信器１４および狭帯域送信器１５を用いる場合においても、目標レーダ帯域ΔＦＸを求めることが可能となる。
【００８７】
なお、スイープさせる第１対抗信号帯域ΔＦＮ１相当の帯域において、平滑な周波数特性を狭帯域目標対抗信号ｎ’（ｔ）で実現できない場合には、実施の形態２と同様に、目標Ｘへ送信される狭帯域目標対抗信号ｎ’（ｔ）の周波数特性｜Ｎ’（ｆ）｜と、目標Ｘから受信される狭帯域目標反射信号ｒ’（ｔ）の正規化周波数特性｜Ｒ’（ｆ）｜／Ｋと用いて、目標レーダ帯域ΔＦＸを求めても良い。
【００８８】
以上のように、この実施の形態５によれば、第１対抗信号帯域ΔＦＮ１内で平滑な周波数特性を有し、第１対抗信号帯域ΔＦＮ１未満の狭帯域で狭帯域目標対抗信号ｎ’（ｔ）を目標対抗信号変調器６が変調し、第１対抗信号帯域ΔＦＮ１にわたって狭帯域目標対抗信号ｎ’（ｔ）を狭帯域送信器１５・局部信号発振器１２・乗算器１３Ａ・送受信空中線１が目標Ｘへスィープ送信するとともに、目標Ｘで反射した狭帯域目標対抗信号ｎ’（ｔ）である狭帯域目標反射信号ｒ’（ｔ）を第１対抗信号帯域ΔＦＮ１にわたって送受信空中線１・局部信号発振器１２・乗算器１３Ｂ・狭帯域受信器１４が目標Ｘからスィープ受信し、狭帯域目標反射信号ｒ’（ｔ）の周波数特性｜Ｒ’（ｆ）｜から算出されるレベル平均値Ａｖｇより一定値だけ低いレベル閾値Ｔｈを周波数分析器４が設定し、レベル閾値Ｔｈ以下のレベルを有する帯域を狭帯域目標反射信号ｒ’（ｔ）の周波数特性｜Ｒ’（ｆ）｜から周波数分析器４が求めて目標レーダ帯域ΔＦＸとするようにしたので、目標対抗装置の送受信帯域が狭い場合でも、目標レーダ帯域ΔＦＸを求めることができるという効果が得られる。
【００８９】
また、この実施の形態５によれば、第１対抗信号帯域ΔＦＮ１内で平滑な周波数特性を有し、第１対抗信号帯域ΔＦＮ１未満の狭帯域で狭帯域目標対抗信号ｎ’（ｔ）を目標対抗信号変調器６が変調して狭帯域送信器１５・局部信号発振器１２・乗算器１３Ａ・送受信空中線１および周波数分析器４へそれぞれ出力し、第１対抗信号帯域ΔＦＮ１にわたって狭帯域目標対抗信号ｎ’（ｔ）を狭帯域送信器１５・局部信号発振器１２・乗算器１３Ａ・送受信空中線１が目標Ｘへスィープ送信するとともに、目標Ｘで反射した狭帯域目標対抗信号ｎ’（ｔ）である狭帯域目標反射信号ｒ’（ｔ）を第１対抗信号帯域ΔＦＮ１にわたって送受信空中線１・局部信号発振器１２・乗算器１３Ｂ・狭帯域受信器１４が目標Ｘからスィープ受信し、狭帯域目標対抗信号ｎ’（ｔ）の周波数特性｜Ｎ’（ｆ）｜によって狭帯域目標反射信号ｒ’（ｔ）の正規化周波数特性｜Ｒ’（ｆ）｜／Ｋを周波数分析器４が除算して目標レーダ帯域ΔＦＸを求めるようにしたので、目標対抗装置の送受信帯域が狭く、第１対抗信号帯域ΔＦＮ１において平滑な周波数特性を持たない狭帯域目標対抗信号ｎ’（ｔ）の場合でも、目標レーダ帯域ΔＦＸを求めることができるという効果が得られる。
【００９０】
実施の形態６．
第１対抗信号帯域ΔＦＮ１の目標対抗信号ｎ（ｔ）の代わりに、目標対抗信号ｎ（ｔ）を目標Ｘのレーダの送信帯域δｆＸに合わせて送信し、その後、目標対抗信号ｎ（ｔ）の変調帯域を送信帯域δｆＸから順次広げて変調し、目標反射信号ｒ（ｔ）を利用して目標レーダ帯域ΔＦＸを求めても良い。
【００９１】
図１１はこの発明の実施の形態６による目標対抗装置の構成を示す図である。図１，９と同一符号は同一または相当する構成である。
【００９２】
図１１に示す構成において、まず目標対抗信号変調器６にてその変調帯域が送信帯域δｆＸに一致するように目標対抗信号ｎ（ｔ）が変調され、次に目標対抗信号ｎ（ｔ）の変調帯域を送信帯域δｆＸから順次広げていく。
【００９３】
図１２はこの発明の実施の形態６による目標対抗装置の動作を説明するための図である。横軸は周波数、縦軸はレベルをそれぞれ表している。
図１２において、｜Ｘ（ｆ）｜，｜Ｎ（ｆ）｜はそれぞれ目標レーダ信号ｘ（ｔ），目標対抗信号ｎ（ｔ）の周波数特性（絶対スペクトル）である。
【００９４】
図１２（ａ）に示すように、目標対抗信号ｎ（ｔ）の変調帯域が目標レーダ帯域ΔＦＸよりも大きくなると、送受信空中線１で受信される目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜のレベルが変化して高くなる。ここでこの目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜のレベル平均値Ａｖｇより一定値高いレベルに設定されたレベル閾値Ｔｈ以上となる帯域を求めることにより、目標レーダ帯域ΔＦＸを求めることが可能となる。
【００９５】
このようにすることで、目標対抗初期における目標対抗信号ｎ（ｔ）の変調帯域が目標Ｘのレーダの送信帯域δｆＸから外れることを防ぐことが可能となる。
【００９６】
なお、送信させる目標対抗信号ｎ（ｔ）の第１対抗信号帯域ΔＦＮ１において平滑な周波数特性を実現できない場合には、実施の形態２と同様に、目標Ｘへ送信される目標対抗信号ｎ（ｔ）の周波数特性｜Ｎ（ｆ）｜によって目標Ｘから受信される目標反射信号ｒ（ｔ）の正規化周波数特性｜Ｒ（ｆ）｜／Ｋを除算して、目標レーダ帯域ΔＦＸを求めても良い。
【００９７】
以上のように、この実施の形態６によれば、目標レーダ信号ｘ（ｔ）の送信帯域δｆＸと第１対抗信号帯域ΔＦＮ１とを一致させて目標対抗信号ｎ（ｔ）を目標対抗信号変調器６が変調するとともに、第１対抗信号帯域ΔＦＮ１を送信帯域δｆＸから順次広げて目標対抗信号ｎ（ｔ）を目標対抗信号変調器６が変調し、第１対抗信号帯域ΔＦＮ１の目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜から算出されるレベル平均値Ａｖｇより一定値だけ低いレベル閾値Ｔｈを周波数分析器４が設定し、レベル閾値Ｔｈ以上のレベルを有する帯域を目標反射信号ｒ（ｔ）の周波数特性｜Ｒ（ｆ）｜から周波数分析器４が求めて目標レーダ帯域ΔＦＸとするようにしたので、目標対抗の初期において、目標レーダ帯域ΔＦＸを求めるために目標対抗信号ｎ（ｔ）が目標Ｘのレーダの送信帯域δｆＸから外れることを防ぎながら、目標レーダ帯域ΔＦＸを求めることができるという効果が得られる。
【００９８】
また、この実施の形態６によれば、目標レーダ信号ｘ（ｔ）の送信帯域δｆＸと第１対抗信号帯域ΔＦＮ１とを一致させて目標対抗信号ｎ（ｔ）を目標対抗信号変調器６が変調するとともに、第１対抗信号帯域ΔＦＮ１を送信帯域δｆＸから順次広げて目標対抗信号ｎ（ｔ）を変調して広帯域送信器７・送受信空中線１および周波数分析器４へ目標対抗信号変調器６がそれぞれ出力し、目標対抗信号ｎ（ｔ）の周波数特性｜Ｎ（ｆ）｜によって目標反射信号ｒ（ｔ）の正規化周波数特性｜Ｒ（ｆ）｜／Ｋを周波数分析器４が除算して目標レーダ帯域ΔＦＸを求めるようにしたので、第１対抗信号帯域ΔＦＮ１において平滑な周波数特性を持たない目標対抗信号ｎ（ｔ）の場合でも、目標対抗の初期において、目標レーダ帯域ΔＦＸを求めるために目標対抗信号ｎ（ｔ）が目標Ｘのレーダの送信帯域δｆＸから外れることを防ぎながら、目標レーダ帯域ΔＦＸを求めることができるという効果が得られる。
【００９９】
実施の形態７．
発明の形態１では、目標レーダ帯域ΔＦＸに絞って目標対抗信号ｎ（ｔ）を送信して、目標のレーダ性能を低下させる場合について述べたが、さらに目標反射信号ｒ（ｔ）を利用して目標Ｘに対する対抗効果の判定を行うようにしても良い。
【０１００】
図１３はこの発明の実施の形態７による目標対抗装置の構成を示す図である。図１と同一符号は同一または相当する構成である。
図１３において、１６は対抗効果判定処理器（対抗効果判定処理手段）、１７はデコイディスペンサー（対抗装置投入手段）である。
【０１０１】
図１３では、実施の形態１に加え、目標Ｘの接近が継続しているか否かによって、目標対抗信号ｎ（ｔ）による対抗効果の判定を行う。目標Ｘの接近度合いの変化により目標反射信号に含まれるドップラ周波数が変化することを利用し、周波数分析器４によって目標レーダ帯域ΔＦＸの変化が検出され、対抗効果判定処理器１６によって対抗効果が判別される。
【０１０２】
図１４はこの発明の実施の形態７による目標対抗装置の動作を説明するための図である。横軸は周波数、縦軸はレベルをそれぞれ表している。
【０１０３】
目標対抗信号ｎ（ｔ）を送信した後（図１４（ａ））、図１４（ｂ）に示すように目標レーダ帯域ΔＦＸが周波数の低い方に変化した場合、目標Ｘが接近しなくなったことを指すので、目標レーダの機能を低下させることができたと判断され、目標対抗信号ｎ（ｔ）による対抗効果は高いと判定される。
【０１０４】
また、図１４（ｃ）に示すように目標レーダ帯域ΔＦＸに変化が無い場合、接近中であることを指すので、目標レーダの機能低下が行えていないと判断され、目標対抗信号ｎ（ｔ）による対抗効果は低いと判定される。
【０１０５】
判定結果は制御器５に出力され、制御器５では、対抗効果の高い場合はそれまでの目標対抗信号ｎ（ｔ）による対抗が継続される。対抗効果の低い場合は対抗装置の追加・変更として、デコイディスペンサー１７が起動されて、目標レーダ探知妨害用のデコイ（おとり、英：ｄｅｃｏｙ）が異なる対抗装置として新たに投入される。
【０１０６】
このようにすることで、目標対抗装置にレーダ装置を備えていない場合でも、目標対抗信号ｎ（ｔ）による対抗効果の判定を行なうことができ、対抗効果の判定によって対抗装置の追加・変更が可能となる。
【０１０７】
以上のように、この実施の形態７によれば、目標反射信号ｎ（ｔ）に含まれるドップラ周波数の変化を検出し、ドップラ周波数の変化に応じて対抗効果を判定する対抗効果判定処理器１６と、対抗効果判定処理器１６で判定された対抗効果によって起動され、目標レーダ探知妨害用のデコイを新たに投入するデコイディスペンサー１７とを備えるようにしたので、目標対抗装置にレーダ装置を備えていない場合でも、目標対抗信号ｎ（ｔ）による対抗効果の判定を行なうことができるという効果が得られ、また対抗効果の判定によって対抗装置の追加・変更ができるという効果が得られる。
【０１０８】
また、この実施の形態７によれば、ドップラ周波数が低い方に変化した場合に対抗効果判定処理器１６が対抗効果を高いと判定するようにしたので、目標Ｘのレーダ機能低下を判定できるという効果が得られる。
【０１０９】
さらに、この実施の形態７によれば、ドップラ周波数が変化していない場合に対抗効果判定処理器１６が対抗効果を低いと判定するようにしたので、目標Ｘのレーダ機能維持を判定できるという効果が得られる。
【０１１０】
なお、この実施の形態７は、実施の形態１への適用に限定されるわけではなく、実施の形態２〜６に適用しても良い。
【０１１１】
また、対抗装置はデコイディスペンサー１７から投入されるデコイに限定されるものではなく、他の対抗装置を追加・変更しても良く、さらに、対抗装置の方式も特に限定されるものではない。
【０１１２】
実施の形態８．
発明の形態１などの手法によって目標レーダ帯域ΔＦＸが明らかになっているので、目標レーダ帯域ΔＦＸを避けた帯域においてレーダ装置の運用を行っても良い。
【０１１３】
図１５はこの発明の実施の形態８による目標対抗装置の構成を示す図である。図１と同一符号は同一または相当する構成である。
図１５において、１８はレーダ装置である。レーダ装置１８は、目標レーダ帯域ΔＦＸが制御器５から与えられ、この目標レーダ帯域ΔＦＸ外においてレーダ信号ｓ（ｔ）を目標Ｘに対して送信するものである。
【０１１４】
このように、この実施の形態８では、実施の形態１の構成（図１）に加えて、目標レーダ帯域ΔＦＸを制御器５から与えられるレーダ装置１８を設け、この目標レーダ帯域ΔＦＸを避けた帯域でレーダ信号ｓ（ｔ）をレーダ装置１８が目標Ｘに対して送信する。
【０１１５】
図１６はこの発明の実施の形態８による目標対抗装置の動作を説明するための図である。横軸は周波数、縦軸はレベルをそれぞれ表している。
図１６において、｜Ｘ（ｆ）｜，｜Ｎ（ｆ）｜，｜Ｓ（ｆ）｜はそれぞれ目標レーダ信号ｘ（ｔ），目標対抗信号ｎ（ｔ），レーダ装置のレーダ信号ｓ（ｔ）の周波数特性（絶対スペクトル）である。
【０１１６】
図１６に示すように、レーダ装置１８の送信するレーダ信号ｓ（ｔ）の対抗レーダ帯域δｆｓは、目標レーダ帯域ΔＦＸや目標対抗信号の第２対抗信号帯域ΔＦＮ２と異なる周波数帯域で運用される。
【０１１７】
このように、目標レーダ信号ｘ（ｔ）や目標対抗信号ｎ（ｔ）などの影響をほとんど受けない周波数帯域で、目標Ｘのレーダ探知が可能となる。
【０１１８】
以上のように、この実施の形態８によれば、周波数分析器４で検出された目標レーダ帯域ΔＦＸを与えられ、目標レーダ帯域ΔＦＸ外においてレーダ信号ｓ（ｔ）を目標Ｘへ送信するレーダ装置１８を備えるようにしたので、目標レーダ信号ｘ（ｔ）や目標対抗信号ｎ（ｔ）などの影響を受けることなく、目標Ｘをレーダ探知できるという効果が得られる。
【０１１９】
なお、この実施の形態８は、実施の形態１への適用に限定されるわけではなく、実施の形態２〜７に適用しても良い。
【０１２０】
【発明の効果】
以上のように、この発明によれば、目標レーダ帯域内の送信帯域で送信される目標レーダ信号を目標から受信し、目標対抗信号を上記目標へ送信する送受信手段と、上記目標レーダ信号から上記送信帯域を検出する信号分析手段と、上記目標レーダ帯域および過剰帯域からなる第１対抗信号帯域で上記目標対抗信号を変調する信号変調手段と、この信号変調手段の変調帯域を切替える制御手段とを備えた目標対抗装置において、上記送受信手段は、上記第１対抗信号帯域にて変調された目標対抗信号を送信して上記目標から反射された目標反射信号を受信し、上記信号分析手段は、上記目標反射信号の周波数特性を求め、その信号レベルの変化から上記目標レーダ帯域を求め、上記制御手段は、上記目標レーダ帯域にて上記目標対抗信号が変調されるよう前記信号変調手段の変調帯域を上記第１対抗信号帯域から上記目標レーダ帯域に切替えるので、従来と異なり、過剰帯域へ無駄な送信を行なうことなく、目標レーダ帯域だけに対して効率的な目標対抗信号の送信を行うことができ、目標のレーダ性能を低下させることができるという効果が得られる。
【０１２１】
この発明によれば、第１対抗信号帯域内で平滑な周波数特性を有する目標対抗信号を信号変調手段が変調し、第１対抗信号帯域の目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を信号分析手段が設定し、レベル閾値以下のレベルを有する帯域を目標反射信号の周波数特性から信号分析手段が求めて目標レーダ帯域とするようにしたので、目標のレーダ開口面における共振現象を利用して、目標レーダ帯域を求めることができるという効果が得られる。
【０１２２】
この発明によれば、第１対抗信号帯域で変調された目標対抗信号を送受信手段および信号分析手段へ信号変調手段がそれぞれ出力し、目標対抗信号の周波数特性によって目標反射信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたので、第１対抗信号帯域において平滑な周波数特性を持たない目標対抗信号の場合でも、目標レーダ帯域を求めることができるという効果が得られる。
【０１２３】
この発明によれば、第１対抗信号帯域のパルス信号を変調して送受信手段および信号分析手段へそれぞれ出力するパルス変調手段を信号変調手段が備え、送受信手段がパルス信号を目標へ送信するとともに、目標で反射したパルス信号である目標反射パルス信号を送受信手段が目標から受信し、パルス信号の周波数特性によって目標反射パルス信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたので、パルス信号１波の送受信が行われる瞬時の間に目標レーダ帯域を求めることが可能となり、第２対抗信号帯域の目標対抗信号を目標へ速く送信できるという効果が得られる。
【０１２４】
この発明によれば、第１対抗信号帯域内で平滑な周波数特性を有するＣＷ信号を変調するＣＷ変調手段を信号変調手段が備え、第１対抗信号帯域にわたってＣＷ信号を目標へ送受信手段がスィープ送信するとともに、目標で反射したＣＷ信号である目標反射ＣＷ信号を第１対抗信号帯域にわたって目標から送受信手段がスィープ受信し、第１対抗信号帯域の目標反射ＣＷ信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を信号分析手段が設定し、レベル閾値以下のレベルを有する帯域を目標反射ＣＷ信号の周波数特性から信号分析手段が求めて目標レーダ帯域とするようにしたので、短時間の間に目標レーダ帯域を求めることができるという効果が得られる。
【０１２５】
この発明によれば、ＣＷ信号を変調して送受信手段および信号分析手段へそれぞれ出力するＣＷ変調手段を信号変調手段が備え、第１対抗信号帯域内にわたってＣＷ信号を目標へ送受信手段がスィープ送信するとともに、目標で反射したＣＷ信号である目標反射ＣＷ信号を第１対抗信号帯域にわたって目標から送受信手段がスィープ受信し、ＣＷ信号の周波数特性によって目標反射ＣＷ信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたので、第１対抗信号帯域において平滑な周波数特性を持たないＣＷ信号の場合でも、短時間の間に目標レーダ帯域を求めることができるという効果が得られる。
【０１２６】
この発明によれば、第１対抗信号帯域内で平滑な周波数特性を有し、第１対抗信号帯域未満の狭帯域で狭帯域目標対抗信号を信号変調手段が変調し、第１対抗信号帯域にわたって狭帯域目標対抗信号を目標へ送受信手段がスィープ送信するとともに、目標で反射した狭帯域目標対抗信号である狭帯域目標反射信号を第１対抗信号帯域にわたって目標から送受信手段がスィープ受信し、狭帯域目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を信号分析手段が設定し、レベル閾値以下のレベルを有する帯域を狭帯域目標反射信号の周波数特性から信号分析手段が求めて目標レーダ帯域とするようにしたので、目標対抗装置の送受信帯域が狭い場合でも、目標レーダ帯域を求めることができるという効果が得られる。
【０１２７】
この発明によれば、第１対抗信号帯域内で平滑な周波数特性を有し、第１対抗信号帯域未満の狭帯域で狭帯域目標対抗信号を信号変調手段が変調して送受信手段および信号分析手段へそれぞれ出力し、第１対抗信号帯域にわたって狭帯域目標対抗信号を目標へ送受信手段がスィープ送信するとともに、目標で反射した狭帯域目標対抗信号である狭帯域目標反射信号を第１対抗信号帯域にわたって目標から送受信手段がスィープ受信し、狭帯域目標対抗信号の周波数特性によって狭帯域目標反射信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたので、目標対抗装置の送受信帯域が狭く、第１対抗信号帯域において平滑な周波数特性を持たない狭帯域目標対抗信号の場合でも、目標レーダ帯域を求めることができるという効果が得られる。
【０１２８】
この発明によれば、目標レーダ信号の送信帯域と第１対抗信号帯域とを一致させて目標対抗信号を信号変調手段が変調するとともに、第１対抗信号帯域を送信帯域から順次広げて目標対抗信号を信号変調手段が変調し、第１対抗信号帯域の目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を信号分析手段が設定し、レベル閾値以上のレベルを有する帯域を目標反射信号の周波数特性から信号分析手段が求めて目標レーダ帯域とするようにしたので、目標対抗の初期において、目標レーダ帯域を求めるために目標対抗信号が目標のレーダの送信帯域から外れることを防ぎながら、目標レーダ帯域を求めることができるという効果が得られる。
【０１２９】
この発明によれば、目標レーダ信号の送信帯域と第１対抗信号帯域とを一致させて目標対抗信号を信号変調手段が変調するとともに、第１対抗信号帯域を送信帯域から順次広げて目標対抗信号を変調して送受信手段および信号分析手段へ信号変調手段がそれぞれ出力し、目標対抗信号の周波数特性によって目標反射信号の正規化周波数特性を信号分析手段が除算して目標レーダ帯域を求めるようにしたので、第１対抗信号帯域において平滑な周波数特性を持たない目標対抗信号の場合でも、目標対抗の初期において、目標レーダ帯域を求めるために目標対抗信号が目標のレーダの送信帯域から外れることを防ぎながら、目標レーダ帯域を求めることができるという効果が得られる。
【０１３０】
この発明によれば、目標反射信号に含まれるドップラ周波数の変化を検出し、ドップラ周波数の変化に応じて対抗効果を判定する対抗効果判定処理手段と、対抗効果判定処理手段で判定された対抗効果によって起動され、異なる対抗装置を新たに投入する対抗装置投入手段とを備えるようにしたので、目標対抗装置にレーダ装置を備えていない場合でも、目標対抗信号による対抗効果の判定を行なうことができるという効果が得られ、また対抗効果の判定によって対抗装置の追加・変更ができるという効果が得られる。
【０１３１】
この発明によれば、ドップラ周波数が低い方に変化した場合に対抗効果判定処理手段が対抗効果を高いと判定するようにしたので、目標のレーダ機能低下を判定できるという効果が得られる。
【０１３２】
この発明によれば、ドップラ周波数が変化していない場合に対抗効果判定処理手段が対抗効果を低いと判定するようにしたので、目標のレーダ機能維持を判定できるという効果が得られる。
【０１３３】
この発明によれば、信号分析手段で検出された目標レーダ帯域を与えられ、目標レーダ帯域外においてレーダ信号を目標へ送信するレーダ装置を備えるようにしたので、目標レーダ信号や目標対抗信号などの影響を受けることなく、目標をレーダ探知できるという効果が得られる。
【図面の簡単な説明】
【図１】 この発明の実施の形態１による目標対抗装置の構成を示す図である。
【図２】 この発明の実施の形態１による目標対抗装置の動作を説明するための図である。
【図３】 この発明の実施の形態２による目標対抗装置の構成を示す図である。
【図４】 この発明の実施の形態２による目標対抗装置の動作を説明するための図である。
【図５】 この発明の実施の形態３による目標対抗装置の構成を示す図である。
【図６】 この発明の実施の形態３による目標対抗装置の動作を説明するための図である。
【図７】 この発明の実施の形態４による目標対抗装置の構成を示す図である。
【図８】 この発明の実施の形態４による目標対抗装置の動作を説明するための図である。
【図９】 この発明の実施の形態５による目標対抗装置の構成を示す図である。
【図１０】 この発明の実施の形態５による目標対抗装置の動作を説明するための図である。
【図１１】 この発明の実施の形態６による目標対抗装置の構成を示す図である。
【図１２】 この発明の実施の形態６による目標対抗装置の動作を説明するための図である。
【図１３】 この発明の実施の形態７による目標対抗装置の構成を示す図である。
【図１４】 この発明の実施の形態７による目標対抗装置の動作を説明するための図である。
【図１５】 この発明の実施の形態８による目標対抗装置の構成を示す図である。
【図１６】 この発明の実施の形態８による目標対抗装置の動作を説明するための図である。
【図１７】 従来の目標対抗装置の構成を示す図である。
【図１８】 従来の目標対抗装置の動作を説明するための図である。
【符号の説明】
１ 送受信空中線（送受信手段）、２ 広帯域受信器（送受信手段）、３ 信号処理器（信号分析手段）、４ 周波数分析器（信号分析手段）、５ 制御器（信号変調手段）、６ 目標対抗信号変調器（信号変調手段）、７ 広帯域送信器（送受信手段）、８ 分岐経路（信号変調手段）、９ パルス変調器（信号変調手段、パルス変調手段）、１０Ａ，１０Ｂ 切替器（信号変調手段）、１１ ＣＷ変調器（信号変調手段、ＣＷ変調手段）、１２ 局部信号発振器（送受信手段）、１３Ａ，１３Ｂ 乗算器（送受信手段）、１４ 狭帯域受信器（送受信手段）、１５ 狭帯域送信器（送受信手段）、１６ 対抗効果判定処理器（対抗効果判定処理手段）、１７ デコイディスペンサー（対抗装置投入手段）、１８ レーダ装置。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a target countermeasure device that efficiently transmits a target countermeasure signal to a target such as an approaching flying object and lowers the radar performance of the target.
[0002]
[Prior art]
FIG. 17 is a diagram showing a configuration of a conventional target countermeasure apparatus.
In FIG. 17, 101 is a transmission / reception antenna (transmission / reception means), 102 is a broadband receiver (transmission / reception means), 103 is a signal processor (signal analysis means), 105 is a controller (signal modulation means), and 106 is target counter signal modulation. Numeral 107 (signal modulation means), 107 is a broadband transmitter (transmission / reception means). Moreover, the code | symbol X is targets, such as a flying body. Further, x (t) is a target radar signal from the target X, and n (t) is a target counter signal transmitted to the target X.
[0003]
Next, the operation will be described.
The target radar signal x (t) from the target X approaching the target countermeasure device is received by the transmission / reception antenna 101, and the transmission band δfX of the target radar signal x (t) is detected by the signal processor 103 via the broadband receiver 102. Is done. When the detection of the transmission band δfX is transmitted from the signal processor 103 to the controller 105, the target counter signal n (t) is transmitted to the target X in order to reduce the radar performance of the target X.
[0004]
That is, a control signal is output from the controller 105 to the target counter signal modulator 106, and the target counter signal modulator 106 modulates the target counter signal n (t). This target countermeasure signal n (t) is transmitted from the transmission / reception antenna 101 to the target X via the broadband transmitter 107. In this way, the radar performance of the target X is lowered.
[0005]
Here, frequency characteristics of the target radar signal x (t) and the target counter signal n (t) will be described.
[0006]
FIG. 18 is a diagram for explaining the operation of the conventional target countermeasure apparatus. The horizontal axis represents the frequency f, and the vertical axis represents the level.
In FIG. 18, | X (f) | and | N (f) | are frequency characteristics (absolute spectrum) of the target radar signal x (t) and the target counter signal n (t), respectively.
[0007]
ΔFX is a usable frequency band of the target radar signal x (t) (hereinafter referred to as a target radar band), ΔFN is a transmission frequency band of the target counter signal n (t) (hereinafter referred to as a counter signal band), ΔFU1 and ΔFU2 is an unnecessary transmission frequency band (hereinafter referred to as an excess band), and has a relationship of ΔFN = ΔFU1 + ΔFX + ΔFU2.
[0008]
As shown in FIG. 18, the target counter signal modulator 106 sets the target counter signal so that the frequency characteristic | N (f) | of the wide counter signal band ΔFN including the transmission band δfX of the frequency characteristic | X (f) | n (t) is modulated. This wideband modulation of the target counter signal n (t) is to cope with a change in the transmission band δfX due to frequency hopping or the like, and the counter signal band ΔFN is added to the target radar band ΔFX of the target radar signal x (t). It includes excess bands ΔFU1, ΔFU2.
[0009]
[Problems to be solved by the invention]
Since the conventional target countermeasure device is configured as described above, there is a problem that transmission of the target countermeasure signal becomes inefficient because the target countermeasure signal is transmitted also to a frequency band outside the target radar band. .
[0010]
This is because the target radar band cannot be detected by the conventional target countermeasure device, so the excessive band must be included in the counter signal band, and the target counter signal modulated by covering the vicinity of the transmission frequency of the target radar over a wide band is transmitted. Because.
[0011]
The present invention has been made to solve the above-described problems, and obtains a target radar band using a target reflection signal from a target, and efficiently transmits a target countermeasure signal by narrowing down to the target radar band. Thus, an object of the present invention is to configure a target countermeasure device capable of reducing the performance of the target radar.
[0012]
[Means for Solving the Problems]
The target countermeasure device according to the present invention is: A transmission / reception means for receiving a target radar signal transmitted in a transmission band within a target radar band from the target, and transmitting a target counter signal to the target; a signal analysis means for detecting the transmission band from the target radar signal; and In a target countermeasure device comprising a signal modulating means for modulating the target counter signal in a first counter signal band consisting of a target radar band and an excess band, and a control means for switching the modulation band of the signal modulating means, the transmitting / receiving means comprises: ,the above First counter signal band Modulated by Target opposition signal Sent and reflected from the target above Target reflection signal Received Belief The signal analysis means is the above Frequency characteristics of target reflected signal Change of its signal level From the above Target radar band Seeking The The control means switches the modulation band of the signal modulation means from the first counter signal band to the target radar band so that the target counter signal is modulated in the target radar band. Is.
[0013]
In the target countermeasure apparatus according to the present invention, the signal modulation means modulates the target countermeasure signal having a smooth frequency characteristic within the first counter signal band, and the level is calculated from the frequency characteristic of the target reflected signal in the first counter signal band. The signal analysis means sets a level threshold value lower than the average value by a certain value, and the signal analysis means obtains a band having a level equal to or lower than the level threshold value from the frequency characteristic of the target reflected signal as the target radar band. .
[0014]
In the target countermeasure apparatus according to the present invention, the signal modulation means outputs the target countermeasure signal modulated in the first counter signal band to the transmission / reception means and the signal analysis means, respectively, and normalizes the target reflected signal according to the frequency characteristic of the target countermeasure signal. The signal analysis means divides the frequency characteristics to obtain the target radar band.
[0015]
The target countermeasure apparatus according to the present invention includes a pulse modulation means that modulates a pulse signal in the first counter signal band and outputs the modulated pulse signal to the transmission / reception means and the signal analysis means, respectively, and the transmission / reception means transmits the pulse signal to the target. In addition, the transmission / reception means receives the target reflected pulse signal, which is a pulse signal reflected by the target, from the target, and the signal analysis means divides the normalized frequency characteristic of the target reflected pulse signal by the frequency characteristic of the pulse signal to obtain the target radar band. Is to ask for.
[0016]
In the target countermeasure apparatus according to the present invention, the signal modulation means includes CW modulation means for modulating a CW signal having a smooth frequency characteristic within the first counter signal band, and the transmission / reception means targets the CW signal over the first counter signal band. The transmission / reception means sweeps the target reflected CW signal, which is a CW signal reflected by the target, over the first counter signal band from the target, and is calculated from the frequency characteristics of the target reflected CW signal in the first counter signal band. The signal analysis means sets a level threshold that is lower than the average level by a certain value, and the signal analysis means obtains a band having a level equal to or lower than the level threshold from the frequency characteristic of the target reflected CW signal as the target radar band. Is.
[0017]
In the target countermeasure apparatus according to the present invention, the signal modulation means includes CW modulation means for modulating the CW signal and outputting the modulated CW signal to the transmission / reception means and the signal analysis means, respectively, and the transmission / reception means sends the CW signal to the target over the first counter signal band. In addition to sweep transmission, the transmission / reception means sweeps the target reflected CW signal, which is a CW signal reflected by the target, from the target over the first counter signal band, and signals the normalized frequency characteristic of the target reflected CW signal according to the frequency characteristic of the CW signal. The analysis means divides and obtains the target radar band.
[0018]
The target countermeasure device according to the present invention has a smooth frequency characteristic within the first counter signal band, the signal modulation means modulates the narrow band target counter signal in a narrow band less than the first counter signal band, and the first counter signal band. The transmission / reception means sweeps and transmits the narrowband target counter signal over the signal band to the target, and the transmission / reception means sweeps and receives the narrowband target reflection signal reflected by the target over the first counter signal band from the target. The signal analysis means sets a level threshold value that is lower than the level average value calculated from the frequency characteristic of the narrow band target reflected signal by a certain value, and a band having a level equal to or lower than the level threshold is signaled from the frequency characteristic of the narrow band target reflected signal The analysis means obtains the target radar band.
[0019]
The target countermeasure apparatus according to the present invention has a smooth frequency characteristic within the first counter signal band, and the signal modulation means modulates the narrow band target counter signal in a narrow band less than the first counter signal band, and the transmission / reception means and Each of the signals is output to the signal analysis means, and the transmission / reception means sweeps and transmits the narrowband target counter signal to the target over the first counter signal band, and the narrowband target reflection signal that is the narrowband target counter signal reflected by the target is the first counter signal. The transmission / reception unit sweeps from the target over the signal band, and the signal analysis unit divides the normalized frequency characteristic of the narrowband target reflected signal by the frequency characteristic of the narrowband target counter signal to obtain the target radar band. .
[0020]
In the target countermeasure apparatus according to the present invention, the signal modulation means modulates the target countermeasure signal by matching the transmission band of the target radar signal with the first counter signal band, and sequentially expands the first counter signal band from the transmission band. The signal modulation unit modulates the target counter signal, and the signal analysis unit sets a level threshold lower than the level average value calculated from the frequency characteristic of the target reflected signal in the first counter signal band, and the level is equal to or higher than the level threshold. Is obtained from the frequency characteristics of the target reflected signal by the signal analysis means to obtain the target radar band.
[0021]
In the target countermeasure apparatus according to the present invention, the signal modulation means modulates the target countermeasure signal by matching the transmission band of the target radar signal with the first counter signal band, and sequentially expands the first counter signal band from the transmission band. The target counter signal is modulated and output to the transmission / reception unit and the signal analysis unit, respectively, and the signal analysis unit divides the normalized frequency characteristic of the target reflected signal by the frequency characteristic of the target counter signal to obtain the target radar band. It is what I did.
[0022]
The target countermeasure device according to the present invention detects a change in Doppler frequency included in the target reflection signal, and is determined by a countermeasure effect determination processing means and a countermeasure effect determination processing means for determining a countermeasure effect according to the change in the Doppler frequency. And a counter device input means that is activated by the counter effect and newly inputs a different counter device.
[0023]
In the target countermeasure apparatus according to the present invention, when the Doppler frequency changes to a lower one, the countermeasure effect determination processing means determines that the countermeasure effect is high.
[0024]
In the target countermeasure device according to the present invention, when the Doppler frequency is not changed, the countermeasure effect determination processing means determines that the countermeasure effect is low.
[0025]
A target countermeasure apparatus according to the present invention is provided with a radar apparatus which is provided with a target radar band detected by a signal analysis means and transmits a radar signal to a target outside the target radar band.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below.
Embodiment 1 FIG.
1 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 1 of the present invention.
In FIG. 1, 1 is a transmission / reception antenna (transmission / reception means), 2 is a broadband receiver (transmission / reception means), 3 is a signal processor (signal analysis means), 4 is a frequency analyzer (signal analysis means), and 5 is a controller ( Signal modulation means), 6 is a target counter signal modulator (signal modulation means), and 7 is a broadband transmitter (transmission / reception means). Moreover, the code | symbol X is targets, such as a flying body. Further, x (t) is a target radar signal transmitted from the target X, n (t) is a target counter signal transmitted to the target X, and r (t) is a target reflection signal received from the target X.
[0027]
Next, the operation will be described.
A target radar signal x (t) from a target X approaching the target counter unit is received by a transmission / reception antenna 1 and input to a signal processor 3 and a frequency analyzer 4 via a broadband receiver 2, and the target radar signal x The transmission band δfX of (t) is detected. When the detection of the transmission band δfX is transmitted from the signal processor 3 / frequency analyzer 4 to the controller 5, a target counter signal n (t) is transmitted to the target X in order to reduce the radar performance of the target X.
[0028]
That is, a control signal is output from the controller 5 to the target counter signal modulator 6, and the target counter signal modulator 6 modulates the target counter signal n (t) in the first counter signal band ΔFN 1. The target counter signal n (t) is transmitted from the transmission / reception antenna 1 to the target X via the broadband transmitter 7.
[0029]
The modulation band of the target counter signal n (t) at this time is the first counter signal band ΔFN1 including the excess bands ΔFU1 and ΔFU2 in addition to the target radar band ΔFX of the target radar signal x (t), as in the prior art. In addition, the frequency characteristic of the target counter signal n (t) is smooth over the first counter signal band ΔFN1.
[0030]
The transmitted target countermeasure signal n (t) is reflected by the target X and is received by the transmitting / receiving antenna 1 as the target reflected signal r (t). This target reflected signal r (t) is input to the frequency analyzer 4 via the broadband receiver 2 and the signal processor 3.
[0031]
On the radar aperture surface of the target X, the electromagnetic wave in the target radar band ΔFX, which is the usable frequency band of the target radar signal x (t), resonates, and part of it is absorbed. The same applies to the broadband target counter signal n (t) transmitted from the transmission / reception antenna 1 to the target X, and a part of the target counter signal n (t) corresponding to the target radar band ΔFX in the first counter signal band ΔFN1. Resonates and is absorbed by the radar aperture of the target X, and the remainder is reflected from the target X as a target reflection signal r (t).
[0032]
That is, if the band absorbed by the radar aperture of the target X is detected from the target reflected signal r (t) of the first counter signal band ΔFN1, the resonance characteristic of the radar aperture of the target X is grasped, and the target radar bandwidth It can be seen that ΔFX is obtained.
[0033]
For example, the signal propagation time and loss between the transmission / reception antenna 1 and the target X are T and K, respectively, the Fourier transform result of the target counter signal n (t) is N (f), and the impulse response of the radar aperture of the target X is g (T), when the Fourier transform result of this impulse response g (t) is G (f), the target reflected signal r (t) and the Fourier transform result R (f) are expressed by the equations (1) and (2), respectively. )become that way.
[0034]
r (t) = Kg (t) * n (t−T) (1)
(However, * is an operator representing convolution)
[0035]
R (f) = KG (f) N (f) exp (−j2πfT) (2)
(Where exp is an exponential function, j is an imaginary number, and π is a pi)
[0036]
In the first embodiment, a smooth frequency characteristic over the first counter signal band ΔFN1, that is, | N (f) | = A (where f1 <f <f2, ΔFN = f2-f1, A is a non-zero constant) ), The target counter signal n (t) is modulated by the target counter signal modulator 6, and therefore the frequency characteristic (absolute spectrum) | R (f) | of the target reflected signal r (t) It becomes like 3).
[0037]
| R (f) | = K | G (f) || N (f) | = KA | G (f) | (3)
(However, || is an absolute value symbol)
[0038]
In this way, the frequency characteristic | G (f) | of the radar aperture of the target X is obtained from the frequency characteristic | R (f) | of the target reflected signal r (t), and this | G (f) | The target radar band ΔFX can be determined from the resonance characteristics of the radar aperture surface of the target X.
[0039]
Specific processing will be described next.
FIG. 2 is a diagram for explaining the operation of the target countermeasure apparatus according to Embodiment 1 of the present invention. The horizontal axis represents frequency and the vertical axis represents level.
In FIG. 2, | X (f) |, | N (f) |, and | R (f) | are the target radar signal x (t), target counter signal n (t), and target reflection signal r (t), respectively. It is a frequency characteristic (absolute spectrum).
[0040]
As shown in FIG. 2A, the frequency analyzer 4 determines the frequency characteristic | R (f) | of the target reflected signal r (t). As described above, in the frequency characteristic | R (f) |, the electromagnetic wave corresponding to the target radar band ΔFX of the target X is absorbed, and the smooth level of the target counter signal n (t) is not maintained.
[0041]
That is, the frequency characteristic | R (f) | of FIG. 2A is RMAX (= KA) in the band outside the target radar band ΔFX, but in the band corresponding to the target radar band ΔFX, The level is reduced from RMAX to RMIN (RMIN <RMAX) due to the resonance characteristics of the radar aperture.
[0042]
The frequency analyzer 4 calculates the level average value Avg of the frequency characteristic | R (f) | over the first counter signal band ΔFN1 from the frequency f1 to the frequency f2 (RMIN <Avg <RMAX), and from this average value Avg A level threshold Th that is lower by a certain value is set (RMIN <Th ≦ Avg <RMAX). Then, the frequency analyzer 4 obtains a region that is equal to or lower than the level threshold Th, that is, a band that has the RMIN level, from the frequency characteristic | R (f) |. The band below the level threshold Th is the resonance band of the radar aperture surface of the target X, and is output from the frequency analyzer 4 to the controller 5 as the target radar band ΔFX.
[0043]
When the target radar band ΔFX is detected from the target reflected signal r (t), the controller is configured to switch the modulation band of the target counter signal n (t) from the first counter signal band ΔFN1 to the second counter signal band ΔFN2. 5 outputs a control signal to the target counter signal modulator 6. Here, the second counter signal band ΔFN2 is a band that matches the target radar band ΔFX. The target counter signal n (t) (FIG. 2B) in the second counter signal band ΔFN2 is modulated by the target counter signal modulator 6 and transmitted from the transmission / reception antenna 1 to the target X via the broadband transmitter 7.
[0044]
The modulation band of the target counter signal n (t) at this point is the second counter signal band ΔFN2 that matches the target radar band ΔFX, and is transmitted only to the target radar band ΔFX, which is a problem in the past. Efficient transmission can be performed only for the target radar band ΔFX without performing unnecessary transmission to the excess bands ΔFU1 and ΔFU2, and the radar performance of the target X can be reduced.
[0045]
As described above, according to the first embodiment, the target reflected signal r (t) reflected by the target counter signal n (t) in the first counter signal band ΔFN1 at the target X is transmitted / received to the transmission / reception antenna 1 and the broadband receiver 2. The signal processor 3 and the frequency analyzer 4 obtain the target radar band ΔFX from the frequency characteristic | R (f) | of the target reflected signal r (t) of the first counter signal band ΔFN1, and the target radar band ΔFX is obtained. Since the controller 5 and the target counter signal modulator 6 modulate the target counter signal n (t) as the second counter signal band ΔFN2, unlike the prior art, without unnecessary transmission to the excess bands ΔFU1, ΔFU2. Thus, it is possible to efficiently transmit the target counter signal n (t) only to the target radar band ΔFX, and the effect that the radar performance of the target X can be reduced is obtained.
[0046]
Further, according to the first embodiment, the controller 5 and the target counter signal modulator 6 generate the target counter signal n (t) having a smooth frequency characteristic | N (f) | within the first counter signal band ΔFN1. The level threshold Th that is modulated and is lower than the level average value Avg calculated from the frequency characteristic | R (f) | of the target reflected signal r (t) in the first counter signal band ΔFN1 by a certain value is the signal processor 3 / frequency analysis. The signal processor 3 and the frequency analyzer 4 obtain a band having a level equal to or lower than the level threshold Th from the frequency characteristic | R (f) | of the target reflected signal r (t), and the target radar band ΔFX. As a result, it is possible to obtain the target radar band ΔFX using the resonance phenomenon in the radar aperture surface of the target X.
[0047]
Embodiment 2. FIG.
In the second embodiment, a method for obtaining the target radar band ΔFX using both the target counter signal n (t) and the target reflection signal r (t) will be described.
[0048]
FIG. 3 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 2 of the present invention. The same reference numerals as those in FIG. 1 denote the same or corresponding configurations.
In FIG. 3, reference numeral 8 denotes a branch path (signal modulating means) for inputting the target counter signal n (t) modulated by the target counter signal modulator 6 to the frequency analyzer 4.
[0049]
FIG. 4 is a diagram for explaining the operation of the target countermeasure apparatus according to Embodiment 2 of the present invention. The horizontal axis represents frequency and the vertical axis represents level.
[0050]
Similar to the first embodiment, when receiving the target radar signal x (t) from the target X, the target countermeasure device according to the second embodiment transmits the target countermeasure signal n (t) from the transmission / reception antenna 1. The target reflected signal r (t) received by the transmitting / receiving antenna 1 is input to the frequency analyzer 4.
[0051]
In the second embodiment, the branch path 8 is provided, and the target counter signal n (t) is input to the frequency analyzer 4 together with the target reflection signal r (t). The frequency analyzer 4 has a frequency characteristic | N (f) | of the target counter signal n (t) shown in FIG. 4A and a frequency characteristic | R of the target reflected signal r (t) shown in FIG. (F) The target radar band ΔFX is obtained from the normalized |.
[0052]
The normalized frequency characteristic | R (f) | / K of the target reflection signal r (t) is expressed by the following equation from the equation (3).
[0053]
| R (f) | / K = | G (f) || N (f) | (4)
[0054]
At this time, the frequency analyzer 4 divides (subtracts in decibels) the equation (4) by the frequency characteristic | N (f) | calculated from the target counter signal n (t) from the branch path 8 to obtain the equation ( The result of 5) is obtained.
[0055]
[| R (f) | / K] / | N (f) | = | G (f) | (5)
[0056]
Thus, by dividing the normalized frequency characteristic | R (f) | / K of the target reflected signal r (t) by the frequency characteristic | N (f) | of the target counter signal n (t), The frequency characteristic | G (f) | of the radar aperture is obtained, and the level threshold value Th is used for the frequency characteristic | G (f) | as in the first embodiment (FIG. 4B). A target radar band ΔFX serving as RMIN is obtained (FIG. 4C).
[0057]
In particular, according to the method of the second embodiment, it is not necessary to realize a smooth level with the frequency characteristic | N (f) | of the target counter signal n (t), and the target radar band ΔFX can be obtained. .
[0058]
As described above, according to the second embodiment, the target counter signal n (t) modulated in the first counter signal band ΔFN1 is transmitted to the transmission / reception antenna 1 and the broadband transmitter 7 and the frequency analyzer 4 as target counter signal modulation. The output of the unit 6 respectively outputs the normalized frequency characteristic | R (f) | / K of the target reflected signal r (t) according to the frequency characteristic | N (f) | of the target counter signal n (t). Since the frequency analyzer 4 divides to obtain the target radar band ΔFX, the target radar band ΔFX is obtained even in the case of the target counter signal n (t) that does not have a smooth frequency characteristic in the first counter signal band ΔFN1. The effect that it can be obtained.
[0059]
Embodiment 3 FIG.
Instead of the target counter signal n (t), a pulse signal p (t) is transmitted to the target X, and this pulse signal p (t) and the target reflected pulse signal rp (t) are used to generate a target radar band. ΔFX may be obtained.
[0060]
FIG. 5 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 3 of the present invention. 1 and 3 are the same or corresponding configurations.
In FIG. 5, 9 is a pulse modulator (signal modulation means, pulse modulation means) provided in parallel with the target counter signal modulator 6, and 10A and 10B are switches (signal modulation means). P (t) and rp (t) are a pulse signal transmitted to the target X and a target reflected pulse signal received from the target X, respectively.
[0061]
In FIG. 5, a pulse modulator 9 modulates a pulse signal p (t) in a wide band (corresponding to the first counter signal band ΔFN1) having a very small pulse width. The pulse signal p (t) is transmitted from the transmission / reception antenna 1 to the target X via the broadband transmitter 7.
[0062]
The pulse signal p (t) is reflected by the target X, received by the transmitting / receiving antenna 1 as the target reflected pulse signal rp (t), and input to the frequency analyzer 4 through the broadband receiver 2 and the signal processor 3. Similar to the second embodiment, the frequency analyzer 4 is provided with a pulse signal p (t) transmitted to the target X and a target reflected pulse signal rp (t) received from the target X.
[0063]
FIG. 6 is a diagram for explaining the operation of the target countermeasure apparatus according to Embodiment 3 of the present invention. The horizontal axis represents frequency and the vertical axis represents level.
In FIG. 6, | X (f) |, | P (f) |, and | RP (f) | are respectively the target radar signal x (t), the pulse signal p (t), and the target reflected pulse signal rp (t). It is a frequency characteristic (absolute spectrum).
[0064]
In the frequency analyzer 4, the normalized frequency characteristic | RP (f) | / K of the target reflected pulse signal rp (t) based on the frequency characteristic | P (f) | (FIG. 6A) of the pulse signal p (t). (FIG. 6 (b)) is divided (subtracted in decibels) to obtain the target radar band ΔFX of FIG. 6 (c).
[0065]
When the target radar band ΔFX is obtained, in FIG. 5, the switches 10A and 10B are switched to disconnect the pulse modulator 9, and instead the target counter signal modulator 6 is connected to the broadband transmitter 7 and the controller 5. The Thereafter, as in the first and second embodiments, the target counter signal n (t) in the second counter signal band ΔFN2 (= ΔFX) is modulated by the target counter signal modulator 6 and transmitted from the transmission / reception antenna 1 to the target X. The
[0066]
Thus, it becomes possible to obtain the target radar band ΔFX during the moment when the transmission / reception of one pulse signal p (t) is performed, and the countermeasure against the target X can be performed quickly.
[0067]
As described above, according to the third embodiment, the pulse modulation that modulates the pulse signal p (t) of the first counter signal band ΔFN1 and outputs the modulated signal to the transmission / reception antenna 1 and the broadband transmitter 7 and the frequency analyzer 4, respectively. The counter 9 is provided in parallel by the target counter signal modulator 6 and the switches 10A and 10B, and the transmission / reception antenna 1 transmits the pulse signal p (t) to the target X, and the pulse signal p (t) reflected by the target X The target reflected pulse signal rp (t) is received from the target X by the transmission / reception antenna 1 and the broadband receiver 2, and the target reflected pulse signal rp (t) is determined by the frequency characteristic | R (f) | of the pulse signal p (t). Since the frequency analyzer 4 divides the normalized frequency characteristic | RP (f) | / K to obtain the target radar band ΔFX, the target is instantaneously transmitted and received for one wave of the pulse signal p (t). Radar band The range ΔFX can be obtained, and the effect that the target counter signal n (t) in the second counter signal band ΔFN2 can be transmitted to the target X quickly is obtained.
[0068]
Embodiment 4 FIG.
Instead of the target counter signal n (t), a CW (Continuous Wave, continuous wave) signal c (t) that sweeps quickly in a short time over a wide band like chirp modulation is transmitted to the target X, and the target reflection CW The target radar band ΔFX may be obtained using the signal rc (t).
[0069]
FIG. 7 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 4 of the present invention. 1 and 5 have the same or corresponding configurations.
In FIG. 7, 11 is a CW modulator (signal modulation means, CW modulation means) provided in parallel with the target counter signal modulator 6 by the switches 10A, 10B, 12 is a local signal oscillator (transmission / reception means), and 13A, 13B. Are multipliers (transmission / reception means).
[0070]
As shown in FIG. 7, first, CW modulation is performed by the CW modulator 11 to generate a CW signal c (t). Here, it is assumed that the CW signal c (t) has a smooth characteristic in the first counter signal band ΔFN1. The CW signal c (t) is input to the multiplier 13A via the broadband transmitter 7. In the multiplier 13A, the sweep signal input from the local signal oscillator 12 and the CW signal c (t) are mixed.
[0071]
Since the frequency of the sweep signal from the local signal oscillator 12 changes over a wide frequency band (corresponding to the first counter signal band ΔFN1) including the target radar band, it is output from the multiplier 13A and transmitted from the transmission / reception antenna 1 to the target X. The CW signal c (t) to be transmitted is sweep-transmitted from the transmission / reception antenna 1 to the target X in a short time like chirp modulation.
[0072]
The CW signal c (t) is reflected by the target X and received by the transmitting / receiving antenna 1 as the target reflected CW signal rc (t). This target reflected CW signal rc (t) is input to the multiplier 13B and is swept by mixing with the sweep signal from the local signal oscillator 12. Thereafter, the target reflected CW signal rc (t) is input to the frequency analyzer 4 through the broadband receiver 2 and the signal processor 3.
[0073]
FIG. 8 is a diagram for explaining the operation of the target countermeasure apparatus according to Embodiment 4 of the present invention. The horizontal axis represents frequency and the vertical axis represents level.
In FIG. 8, | X (f) |, | N (f) |, and | RC (f) | are a target radar signal x (t), a target counter signal n (t), and a target reflection CW signal rc (t), respectively. Frequency characteristics (absolute spectrum).
[0074]
The frequency analyzer 4 refers to the frequency of the sweep signal from the local signal oscillator 12 and obtains the frequency characteristic | RC (f) | of the target reflected CW signal rc (t) as in the first embodiment (see FIG. 8 (a)). The target radar band ΔFX can be obtained by obtaining a band that is equal to or lower than the level threshold value Th set to a level lower than the level average value Avg of the frequency characteristic | RC (f) |.
[0075]
By doing so, it is possible to obtain the target radar band ΔFX in a short time during which the CW signal c (t) is swept.
[0076]
In the subsequent operation, the target counter signal modulator 6 is connected to the controller 5 and the broadband transmitter 7 in place of the CW modulator 11 by the switches 10A and 10B, as in the third embodiment, and the second counter signal band. The target counter signal n (t) (FIG. 8B) modulated by the target counter signal modulator 6 in the band of ΔFN2 (= ΔFX) is transmitted to the target X through the broadband transmitter 7 and the transmission / reception antenna 1. When the target counter signal n (t) in the second counter signal band ΔFN2 is transmitted, the sweep signal is not output from the local signal oscillator 12, and the multipliers 13A and 13B enter the through state.
[0077]
If a smooth frequency characteristic cannot be realized with the CW signal c (t) in the band corresponding to the first counter signal band ΔFN1 to be swept, the CW signal c transmitted to the target X is the same as in the second embodiment. The target radar band ΔFX is obtained by dividing the normalized frequency characteristic | RC (f) | / K of the target reflected CW signal rc (t) received from the target X by the frequency characteristic | C (f) | of (t). You may ask.
[0078]
As described above, according to the fourth embodiment, the CW modulator 11 that modulates the CW signal c (t) having a smooth frequency characteristic within the first counter signal band ΔFN1 is switched to the target counter by the switches 10A and 10B. In parallel with the signal modulator 6, the broadband transmitter 7, the local signal oscillator 12, the multiplier 13A, and the transmission / reception antenna 1 sweep the CW signal c (t) over the first counter signal band ΔFN1 to the target X. The target reflected CW signal rc (t), which is the CW signal c (t) reflected by X, is transmitted / received from the target X by the transmitting / receiving antenna 1, local signal oscillator 12, multiplier 13B, and broadband receiver 2 over the first counter signal band ΔFN1. Received and lower than the level average value Avg calculated from the frequency characteristic | RC (f) | of the target reflected CW signal rc (t) in the first counter signal band ΔFN1 by a certain value The frequency threshold value Th is set by the frequency analyzer 4 and the frequency analyzer 4 obtains a band having a level equal to or lower than the level threshold value Th from the frequency characteristic | RC (f) | of the target reflected CW signal rc (t). Since ΔFX is set, it is possible to obtain the target radar band ΔFX in a short time.
[0079]
As described above, according to the fourth embodiment, the CW signal c (t) is modulated and output to the broadband transmitter 7, the local signal oscillator 12, the multiplier 13 A, the transmission / reception antenna 1 and the frequency analyzer 4, respectively. The CW modulator 11 is provided in parallel with the target counter signal modulator 6 by the switches 10A and 10B, and the CW signal c (t) is transmitted over the first counter signal band ΔFN1 to the wide band transmitter 7, the local signal oscillator 12, and the multiplier 13A. The transmission / reception antenna 1 sweeps to the target X, and the target reflected CW signal rc (t), which is the CW signal c (t) reflected by the target X, is transmitted / received to the transmission / reception antenna 1 / local signal oscillator 12 over the first counter signal band ΔFN1. The multiplier 13B and the broadband receiver 2 receive the sweep from the target X, and the frequency characteristic | C (f) | of the CW signal c (t) indicates the target reflected CW signal rc (t). Since the frequency analyzer 4 divides the normalized frequency characteristic | RC (f) | / K to obtain the target radar band ΔFX, the CW signal c () having no smooth frequency characteristic in the first counter signal band ΔFN1. Even in the case of t), the effect that the target radar band ΔFX can be obtained in a short time is obtained.
[0080]
Embodiment 5 FIG.
Instead of the target counter signal n (t) in the first counter signal band ΔFN1, the target counter signal n ′ (t) in the narrow band (less than the first counter signal band ΔFN1) is transmitted in a sweep over the first counter signal band ΔFN1. The target radar band ΔFX may be obtained using the target reflection signal r ′ (t).
[0081]
FIG. 9 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 5 of the present invention. 1 and 7 have the same or corresponding configurations.
In FIG. 9, 14 is a narrow band receiver (transmission / reception means), and 15 is a narrow band transmitter (transmission / reception means). Further, n ′ (t) is a narrowband target counter signal, and r ′ (t) is a narrowband target reflection signal.
[0082]
As shown in FIG. 9, the target counter signal modulator 6 modulates the narrowband target counter signal n ′ (t). This narrow-band target counter signal n ′ (t) has smooth characteristics in the frequency band to be swept. The narrowband target counter signal n ′ (t) is input to the multiplier 13A through the narrowband transmitter 15 and is mixed by the sweep signal from the local signal oscillator 12 and the multiplier 13A as in the fourth embodiment, Sweep transmission is performed from the transmission / reception antenna 1 to the target X over a wide frequency band including the radar band ΔFX (corresponding to the first counter signal band ΔFN1).
[0083]
The narrowband target counter signal n ′ (t) is reflected by the target X, and is sweep-received from the target X by the transmission / reception antenna 1 as the narrowband target counter signal n ′ (t), as in the fourth embodiment. The narrowband target counter signal n ′ (t) received by the sweep is input to the frequency analyzer 4 through the narrowband receiver 14 and the signal processor 3.
[0084]
FIG. 10 is a diagram for explaining the operation of the target countermeasure apparatus according to Embodiment 5 of the present invention. The horizontal axis represents frequency and the vertical axis represents level.
In FIG. 10, | X (f) |, | N ′ (f) |, | R ′ (f) | are the target radar signal x (t), the narrowband target counter signal n ′ (t), and the narrowband target, respectively. It is a frequency characteristic (absolute spectrum) of the reflected signal r ′ (t).
[0085]
In the frequency analyzer 4, as in the first and fourth embodiments, the frequency characteristic | R ′ (f) | of the narrowband target reflected signal r ′ (t) is obtained, and as shown in FIG. The target radar band ΔFX can be obtained by obtaining a band that is equal to or lower than the level threshold value Th set to a level lower than the level average value Avg of the frequency characteristic | R ′ (f) |.
[0086]
Thus, even when the narrow band receiver 14 and the narrow band transmitter 15 are used, the target radar band ΔFX can be obtained.
[0087]
If a smooth frequency characteristic cannot be realized with the narrow band target counter signal n ′ (t) in the band corresponding to the first counter signal band ΔFN1 to be swept, it is transmitted to the target X as in the second embodiment. Frequency characteristic | N ′ (f) | of the narrowband target counter signal n ′ (t) and the normalized frequency characteristic | R ′ (f) of the narrowband target reflection signal r ′ (t) received from the target X | / K may be used to determine the target radar band ΔFX.
[0088]
As described above, according to the fifth embodiment, the narrow-band target counter signal n ′ (t having a smooth frequency characteristic in the first counter-signal band ΔFN1 and a narrow band less than the first counter-signal band ΔFN1. ) Is modulated by the target counter signal modulator 6, and the narrow band target counter signal n ′ (t) over the first counter signal band ΔFN 1 is targeted by the narrow band transmitter 15, the local signal oscillator 12, the multiplier 13 A, and the transmission / reception antenna 1. A narrowband target reflected signal r ′ (t), which is a narrowband target counter signal n ′ (t) reflected by the target X, is transmitted / received to X over the first counter signal band ΔFN1. The multiplier 13B and the narrowband receiver 14 receive the sweep from the target X, and only a fixed value from the level average value Avg calculated from the frequency characteristic | R ′ (f) | of the narrowband target reflected signal r ′ (t). Low level threshold The frequency analyzer 4 sets Th, and the frequency analyzer 4 obtains a band having a level equal to or lower than the level threshold Th from the frequency characteristic | R ′ (f) | of the narrowband target reflected signal r ′ (t). Since the band ΔFX is used, the target radar band ΔFX can be obtained even when the transmission / reception band of the target countermeasure device is narrow.
[0089]
Further, according to the fifth embodiment, the target frequency is a narrow band target counter signal n ′ (t) having a smooth frequency characteristic in the first counter signal band ΔFN1 and a narrow band less than the first counter signal band ΔFN1. The counter signal modulator 6 modulates and outputs to the narrow band transmitter 15, the local signal oscillator 12, the multiplier 13A, the transmitting / receiving antenna 1 and the frequency analyzer 4, respectively, and the narrow band target counter signal n over the first counter signal band ΔFN1. Narrowband target counter signal n ′ (t) reflected by target X while narrow band transmitter 15, local signal oscillator 12, multiplier 13 A, and transmission / reception antenna 1 sweep to transmit “(t)”. The transmission / reception antenna 1, the local signal oscillator 12, the multiplier 13B, and the narrow band receiver 14 sweep the band target reflected signal r ′ (t) from the target X over the first counter signal band ΔFN1, The frequency analyzer 4 divides the normalized frequency characteristic | R ′ (f) | / K of the narrowband target reflected signal r ′ (t) by the frequency characteristic | N ′ (f) | of the signal n ′ (t). Since the target radar band ΔFX is obtained, even in the case of the narrowband target counter signal n ′ (t) in which the transmission / reception band of the target counter apparatus is narrow and the first counter signal band ΔFN1 does not have a smooth frequency characteristic, the target radar The effect that the band ΔFX can be obtained is obtained.
[0090]
Embodiment 6 FIG.
Instead of the target counter signal n (t) in the first counter signal band ΔFN1, the target counter signal n (t) is transmitted in accordance with the transmission band δfX of the radar of the target X, and then the target counter signal n (t) The modulation may be performed by sequentially expanding the modulation band from the transmission band δfX, and the target radar band ΔFX may be obtained using the target reflected signal r (t).
[0091]
FIG. 11 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 6 of the present invention. 1 and 9 have the same or corresponding configurations.
[0092]
In the configuration shown in FIG. 11, the target counter signal n (t) is first modulated by the target counter signal modulator 6 so that the modulation band coincides with the transmission band δfX, and then the target counter signal n (t) is modulated. The band is sequentially expanded from the transmission band δfX.
[0093]
FIG. 12 is a diagram for explaining the operation of the target countermeasure apparatus according to Embodiment 6 of the present invention. The horizontal axis represents frequency and the vertical axis represents level.
In FIG. 12, | X (f) | and | N (f) | are frequency characteristics (absolute spectrum) of the target radar signal x (t) and the target counter signal n (t), respectively.
[0094]
As shown in FIG. 12A, when the modulation band of the target counter signal n (t) becomes larger than the target radar band ΔFX, the frequency characteristic | R (of the target reflected signal r (t) received by the transmission / reception antenna 1 f) The level of | changes and becomes higher. Here, the target radar band ΔFX is obtained by obtaining a band that is equal to or higher than the level threshold value Th set to a level higher than the level average value Avg of the frequency characteristic | R (f) | of the target reflected signal r (t). It can be obtained.
[0095]
In this way, it is possible to prevent the modulation band of the target counter signal n (t) at the initial stage of target countering from deviating from the transmission band δfX of the radar of the target X.
[0096]
If smooth frequency characteristics cannot be realized in the first counter signal band ΔFN1 of the target counter signal n (t) to be transmitted, the target counter signal n (t) transmitted to the target X is the same as in the second embodiment. ) To obtain the target radar band ΔFX by dividing the normalized frequency characteristic | R (f) | / K of the target reflected signal r (t) received from the target X by the frequency characteristic | N (f) | good.
[0097]
As described above, according to the sixth embodiment, the target counter signal n (t) is made the target counter signal modulator by matching the transmission band δfX of the target radar signal x (t) with the first counter signal band ΔFN1. 6 modulates the target counter signal band ΔFN1 sequentially from the transmission band δfX to modulate the target counter signal n (t) by the target counter signal modulator 6, and the target reflected signal r (1) of the first counter signal band ΔFN1. The frequency analyzer 4 sets a level threshold Th that is lower than the level average value Avg calculated from the frequency characteristic | R (f) | of t) by a certain value, and a band having a level equal to or higher than the level threshold Th is set as the target reflected signal r. Since the frequency analyzer 4 obtains the target radar band ΔFX from the frequency characteristic | R (f) | of (t) and sets it as the target radar band ΔFX, in order to obtain the target radar band ΔFX in the initial stage of the target competition, the target counter signal n While preventing that t) deviates from the transmission band δfX radar target X, there is an advantage that it is possible to determine a target radar band DerutaFX.
[0098]
Further, according to the sixth embodiment, the target counter signal modulator 6 modulates the target counter signal n (t) by matching the transmission band δfX of the target radar signal x (t) with the first counter signal band ΔFN1. At the same time, the first counter signal band ΔFN1 is sequentially expanded from the transmission band δfX to modulate the target counter signal n (t), and the target counter signal modulator 6 is supplied to the wideband transmitter 7, the transmission / reception antenna 1 and the frequency analyzer 4, respectively. The frequency analyzer 4 divides the normalized frequency characteristic | R (f) | / K of the target reflected signal r (t) by the frequency characteristic | N (f) | of the target counter signal n (t). Since the radar band ΔFX is obtained, in order to obtain the target radar band ΔFX at the initial stage of the target competition even in the case of the target competition signal n (t) having no smooth frequency characteristic in the first counter signal band ΔFN1. While preventing that the target counter signal n (t) is out of the transmission band δfX radar target X, there is an advantage that it is possible to determine a target radar band DerutaFX.
[0099]
Embodiment 7 FIG.
In the first aspect of the invention, the case has been described in which the target opposition signal n (t) is transmitted by narrowing down to the target radar band ΔFX and the radar performance of the target is lowered, but the target reflection signal r (t) is further used. You may make it determine the opposition effect with respect to the target X. FIG.
[0100]
FIG. 13 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 7 of the present invention. The same reference numerals as those in FIG. 1 denote the same or corresponding configurations.
In FIG. 13, 16 is a counter effect determination processing device (counter effect determination processing means), and 17 is a decoy dispenser (counter device input means).
[0101]
In FIG. 13, in addition to the first embodiment, the counter effect is determined by the target counter signal n (t) depending on whether or not the target X is approaching. Utilizing the fact that the Doppler frequency included in the target reflection signal changes due to the change in the degree of approach of the target X, the frequency analyzer 4 detects the change in the target radar band ΔFX, and the counter effect determination processor 16 determines the counter effect. Is done.
[0102]
FIG. 14 is a diagram for explaining the operation of the target countermeasure apparatus according to Embodiment 7 of the present invention. The horizontal axis represents frequency and the vertical axis represents level.
[0103]
After transmitting the target counter signal n (t) (FIG. 14 (a)), the target X is no longer approaching when the target radar band ΔFX changes to the lower frequency as shown in FIG. 14 (b). Therefore, it is determined that the function of the target radar has been reduced, and it is determined that the counter effect by the target counter signal n (t) is high.
[0104]
Further, as shown in FIG. 14C, when there is no change in the target radar band ΔFX, it means that the target radar is approaching. Therefore, it is determined that the function of the target radar has not been reduced, and the target counter signal n (t) It is determined that the counter effect by is low.
[0105]
The determination result is output to the controller 5. In the controller 5, when the counter effect is high, the countering by the target counter signal n (t) so far is continued. When the countermeasure effect is low, the decoy dispenser 17 is activated as a countermeasure device addition / change, and the target radar detection decoy (decoy) is newly introduced as a different countermeasure device.
[0106]
By doing in this way, even when the target countermeasure device is not equipped with a radar device, it is possible to determine the counter effect by the target counter signal n (t), and the counter device can be added or changed by the determination of the counter effect. It becomes possible.
[0107]
As described above, according to the seventh embodiment, a countermeasure effect determination processor 16 that detects a change in Doppler frequency included in the target reflection signal n (t) and determines a countermeasure effect according to the change in Doppler frequency. And the decoy dispenser 17 that is activated by the counter effect determined by the counter effect determination processor 16 and newly inputs a decoy for disturbing the target radar detection. Even when there is not, the effect that the counter effect can be determined by the target counter signal n (t) is obtained, and the effect that the counter device can be added or changed by the determination of the counter effect is obtained.
[0108]
Further, according to the seventh embodiment, when the Doppler frequency is changed to a lower one, the countermeasure effect determination processor 16 determines that the countermeasure effect is high, so that it is possible to determine the radar function deterioration of the target X. An effect is obtained.
[0109]
Furthermore, according to the seventh embodiment, when the Doppler frequency is not changed, the countermeasure effect determination processor 16 determines that the countermeasure effect is low, so that it is possible to determine whether the radar function maintenance of the target X can be determined. Is obtained.
[0110]
The seventh embodiment is not limited to the application to the first embodiment, and may be applied to the second to sixth embodiments.
[0111]
Further, the counter device is not limited to the decoy that is input from the decoy dispenser 17, other counter devices may be added or changed, and the method of the counter device is not particularly limited.
[0112]
Embodiment 8 FIG.
Since the target radar band ΔFX has been clarified by the method of the first aspect of the invention, the radar apparatus may be operated in a band that avoids the target radar band ΔFX.
[0113]
FIG. 15 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 8 of the present invention. The same reference numerals as those in FIG. 1 denote the same or corresponding configurations.
In FIG. 15, 18 is a radar apparatus. The radar apparatus 18 is provided with a target radar band ΔFX from the controller 5 and transmits a radar signal s (t) to the target X outside the target radar band ΔFX.
[0114]
As described above, in the eighth embodiment, in addition to the configuration of the first embodiment (FIG. 1), the radar device 18 provided with the target radar band ΔFX from the controller 5 is provided, and the target radar band ΔFX is avoided. The radar device 18 transmits the radar signal s (t) to the target X in the band.
[0115]
FIG. 16 is a view for explaining the operation of the target countermeasure apparatus according to Embodiment 8 of the present invention. The horizontal axis represents frequency and the vertical axis represents level.
In FIG. 16, | X (f) |, | N (f) |, and | S (f) | are the target radar signal x (t), the target counter signal n (t), and the radar signal s (t) of the radar apparatus, respectively. ) Frequency characteristics (absolute spectrum).
[0116]
As shown in FIG. 16, the radar radar band δfs of the radar signal s (t) transmitted by the radar apparatus 18 is operated in a frequency band different from the target radar band ΔFX and the second counter signal band ΔFN2 of the target counter signal.
[0117]
Thus, radar detection of the target X can be performed in a frequency band that is hardly affected by the target radar signal x (t), the target counter signal n (t), and the like.
[0118]
As described above, according to the eighth embodiment, the radar apparatus is provided with the target radar band ΔFX detected by the frequency analyzer 4 and transmits the radar signal s (t) to the target X outside the target radar band ΔFX. 18 is provided, the effect that the target X can be detected by the radar without being affected by the target radar signal x (t), the target counter signal n (t), or the like can be obtained.
[0119]
The eighth embodiment is not limited to the application to the first embodiment, and may be applied to the second to seventh embodiments.
[0120]
【The invention's effect】
As described above, according to the present invention, A transmission / reception means for receiving a target radar signal transmitted in a transmission band within a target radar band from the target, and transmitting a target counter signal to the target; a signal analysis means for detecting the transmission band from the target radar signal; and In a target countermeasure device comprising a signal modulating means for modulating the target counter signal in a first counter signal band consisting of a target radar band and an excess band, and a control means for switching the modulation band of the signal modulating means, the transmitting / receiving means comprises: ,the above First counter signal band Modulated by Target opposition signal Sent and reflected from the target above Target reflection signal Received Belief The signal analysis means is the above Frequency characteristics of target reflected signal Change of its signal level From the above Target radar band Seeking The The control means switches the modulation band of the signal modulation means from the first counter signal band to the target radar band so that the target counter signal is modulated in the target radar band. Therefore, unlike the conventional case, the target counter signal can be efficiently transmitted only to the target radar band without wasteful transmission to the excessive band, and the target radar performance can be reduced. Is obtained.
[0121]
According to this invention, the signal modulation means modulates the target counter signal having a smooth frequency characteristic within the first counter signal band, and the level average value calculated from the frequency characteristic of the target reflected signal in the first counter signal band. Since the signal analysis means sets a level threshold that is lower by a certain value, and the band having a level equal to or lower than the level threshold is determined by the signal analysis means from the frequency characteristics of the target reflected signal, it is set as the target radar band. The effect that the target radar band can be obtained by using the resonance phenomenon in the surface is obtained.
[0122]
According to the present invention, the signal modulation unit outputs the target counter signal modulated in the first counter signal band to the transmission / reception unit and the signal analysis unit, respectively, and the normalized frequency characteristic of the target reflection signal is determined by the frequency characteristic of the target counter signal. Since the signal analysis means divides and obtains the target radar band, the target radar band can be obtained even in the case of a target counter signal that does not have a smooth frequency characteristic in the first counter signal band. .
[0123]
According to the present invention, the signal modulation means includes the pulse modulation means for modulating the pulse signal of the first counter signal band and outputting the modulated signal to the transmission / reception means and the signal analysis means, respectively, and the transmission / reception means transmits the pulse signal to the target, The transmission / reception means receives the target reflected pulse signal, which is a pulse signal reflected at the target, from the target, and the signal analysis means divides the normalized frequency characteristic of the target reflected pulse signal by the frequency characteristic of the pulse signal to obtain the target radar band. As a result, the target radar band can be obtained at the instant when one pulse signal is transmitted and received, and the target counter signal in the second counter signal band can be quickly transmitted to the target.
[0124]
According to the present invention, the signal modulation means includes the CW modulation means for modulating the CW signal having smooth frequency characteristics within the first counter signal band, and the transmission / reception means sweeps the CW signal to the target over the first counter signal band. In addition, the target reflected CW signal, which is the CW signal reflected by the target, is swept from the target by the transmission / reception means over the first counter signal band, and the level average calculated from the frequency characteristic of the target reflected CW signal in the first counter signal band Since the signal analysis means sets a level threshold lower than the value by a certain value, and the signal analysis means obtains a band having a level equal to or lower than the level threshold from the frequency characteristic of the target reflected CW signal, it is set as the target radar band. The effect is that the target radar band can be obtained during the time.
[0125]
According to the present invention, the signal modulation means includes the CW modulation means for modulating the CW signal and outputting it to the transmission / reception means and the signal analysis means, respectively, and the transmission / reception means sweeps the CW signal to the target within the first counter signal band. At the same time, the target reflection CW signal, which is the CW signal reflected from the target, is swept from the target by the transmission / reception means over the first counter signal band, and the signal analysis means obtains the normalized frequency characteristic of the target reflection CW signal according to the frequency characteristic of the CW signal. Since the target radar band is obtained by division, an effect is obtained that the target radar band can be obtained in a short time even in the case of a CW signal having no smooth frequency characteristic in the first counter signal band. .
[0126]
According to this invention, the signal modulation means has a smooth frequency characteristic within the first counter signal band, the narrow band target counter signal is modulated in a narrow band less than the first counter signal band, and the first counter signal band is spread over the first counter signal band. The transmitter / receiver sweeps the narrowband target counter signal to the target, and the transmitter / receiver sweeps the narrowband target reflected signal, which is a narrowband target counter signal reflected by the target, from the target over the first counter signal band. The signal analysis means sets a level threshold lower than the level average value calculated from the frequency characteristic of the target reflection signal by a certain value, and the signal analysis means sets the band having a level equal to or lower than the level threshold from the frequency characteristic of the narrowband target reflection signal. Since the target radar band is obtained, the target radar band can be obtained even when the transmission / reception band of the target countermeasure device is narrow. It is.
[0127]
According to the present invention, the signal modulating means modulates the narrow band target counter signal in a narrow band less than the first counter signal band and has a smooth frequency characteristic within the first counter signal band, and the transmitting / receiving means and the signal analyzing means The transmission / reception means sweeps and transmits the narrowband target counter signal over the first counter signal band to the target, and the narrowband target counter signal reflected by the target is transmitted over the first counter signal band. The transmitter / receiver sweeps from the target, and the signal analysis means divides the normalized frequency characteristic of the narrowband target reflected signal by the frequency characteristic of the narrowband target counter signal so as to obtain the target radar band. The target radar band can be obtained even in the case of a narrow band target counter signal that has a narrow transmission / reception band and does not have a smooth frequency characteristic in the first counter signal band. The effect of wear can be obtained.
[0128]
According to the present invention, the target modulation signal is modulated by the signal modulation means by matching the transmission band of the target radar signal with the first counter signal band, and the first counter signal band is sequentially expanded from the transmission band to target the target signal. The signal modulation means modulates the signal, and the signal analysis means sets a level threshold value lower than the level average value calculated from the frequency characteristic of the target reflected signal in the first counter signal band by the signal analysis means, and has a level equal to or higher than the level threshold value. Since the signal analysis means obtains the target radar band from the frequency characteristics of the target reflected signal, the target counter signal must deviate from the transmission band of the target radar in order to obtain the target radar band in the initial stage of the target opposition. The effect that the target radar band can be obtained while preventing the problem is obtained.
[0129]
According to the present invention, the target modulation signal is modulated by the signal modulation means by matching the transmission band of the target radar signal with the first counter signal band, and the first counter signal band is sequentially expanded from the transmission band to target the target signal. The signal modulation means outputs the signal to the transmission / reception means and the signal analysis means, and the signal analysis means divides the normalized frequency characteristic of the target reflected signal by the frequency characteristic of the target counter signal to obtain the target radar band. Therefore, even in the case of a target counter signal that does not have a smooth frequency characteristic in the first counter signal band, the target counter signal is prevented from deviating from the target radar transmission band in order to obtain the target radar band in the initial stage of the target counter. However, it is possible to obtain the target radar band.
[0130]
According to the present invention, a change in the Doppler frequency included in the target reflection signal is detected, and a counter effect determination processing unit that determines a counter effect according to the change in the Doppler frequency, and a counter effect determined by the counter effect determination processing unit And a counter-device input means for newly inputting a different counter device, so that even if the target counter device is not equipped with a radar device, it is possible to determine the counter effect using the target counter signal. In addition, it is possible to add or change a countermeasure device by determining the countermeasure effect.
[0131]
According to the present invention, when the Doppler frequency is changed to a lower one, the countermeasure effect determination processing unit determines that the countermeasure effect is high, so that it is possible to determine the target radar function deterioration.
[0132]
According to the present invention, when the Doppler frequency is not changed, the countermeasure effect determination processing means determines that the countermeasure effect is low, so that an effect of determining whether the target radar function is maintained can be obtained.
[0133]
According to the present invention, the radar device is provided which is provided with the target radar band detected by the signal analysis means and transmits the radar signal to the target outside the target radar band. The effect is obtained that the target can be detected by the radar without being affected.
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 1 of the present invention.
FIG. 2 is a diagram for explaining the operation of a target countermeasure device according to Embodiment 1 of the present invention;
FIG. 3 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 2 of the present invention.
FIG. 4 is a diagram for explaining the operation of a target countermeasure device according to Embodiment 2 of the present invention;
FIG. 5 is a diagram showing a configuration of a target countermeasure device according to Embodiment 3 of the present invention.
FIG. 6 is a diagram for explaining the operation of a target countermeasure device according to Embodiment 3 of the present invention;
FIG. 7 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 4 of the present invention.
FIG. 8 is a diagram for explaining the operation of a target countermeasure device according to Embodiment 4 of the present invention;
FIG. 9 is a diagram showing a configuration of a target countermeasure device according to Embodiment 5 of the present invention.
FIG. 10 is a diagram for explaining the operation of a target countermeasure device according to Embodiment 5 of the present invention;
FIG. 11 is a diagram showing a configuration of a target countermeasure apparatus according to Embodiment 6 of the present invention.
FIG. 12 is a diagram for explaining the operation of a target countermeasure device according to Embodiment 6 of the present invention;
FIG. 13 is a diagram showing a configuration of a target countermeasure device according to Embodiment 7 of the present invention.
FIG. 14 is a diagram for explaining the operation of a target countermeasure device according to Embodiment 7 of the present invention;
FIG. 15 is a diagram showing a configuration of a target countermeasure device according to Embodiment 8 of the present invention.
FIG. 16 is a diagram for explaining the operation of a target countermeasure device according to Embodiment 8 of the present invention;
FIG. 17 is a diagram showing a configuration of a conventional target countermeasure device.
FIG. 18 is a diagram for explaining the operation of a conventional target countermeasure device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Transmission / reception antenna (transmission / reception means), 2 Broadband receiver (transmission / reception means), 3 Signal processor (signal analysis means), 4 Frequency analyzer (signal analysis means), 5 Controller (signal modulation means), 6 Target opposition signal Modulator (signal modulation means), 7 Broadband transmitter (transmission / reception means), 8 Branch path (signal modulation means), 9 Pulse modulator (signal modulation means, pulse modulation means), 10A, 10B Switch (signal modulation means) , 11 CW modulator (signal modulation means, CW modulation means), 12 local signal oscillator (transmission / reception means), 13A, 13B multiplier (transmission / reception means), 14 narrowband receiver (transmission / reception means), 15 narrowband transmitter ( (Transmission / reception means), 16 counter effect determination processor (counter effect determination processing means), 17 decoy dispenser (counter device input means), 18 radar device.

Claims (14)

目標レーダ帯域内の送信帯域で送信される目標レーダ信号を目標から受信し、目標対抗信号を上記目標へ送信する送受信手段と、上記目標レーダ信号から上記送信帯域を検出する信号分析手段と、上記目標レーダ帯域および過剰帯域からなる第１対抗信号帯域で上記目標対抗信号を変調する信号変調手段と、この信号変調手段の変調帯域を切替える制御手段とを備えた目標対抗装置において、
上記送受信手段は、上記第１対抗信号帯域にて変調された目標対抗信号を送信して上記目標から反射された目標反射信号を受信し、
上記信号分析手段は、上記目標反射信号の周波数特性を求め、その信号レベルの変化から上記目標レーダ帯域を求め、
上記制御手段は、上記目標レーダ帯域にて上記目標対抗信号が変調されるよう前記信号変調手段の変調帯域を上記第１対抗信号帯域から上記目標レーダ帯域に切替えることを特徴とする目標対抗装置。 Receiving a target radar signal transmitted by the transmission band of the target radar band from the target, a receiving means for a target opposing signal transmitted to the target, a signal analyzing means for detecting the transmission bandwidth from the target radar signal, the In a target countermeasure device comprising a signal modulating means for modulating the target opposing signal in a first opposing signal band comprising a target radar band and an excess band, and a control means for switching the modulation band of the signal modulating means ,
The transmitting / receiving means transmits a target counter signal modulated in the first counter signal band and receives a target reflected signal reflected from the target;
Said signal analyzing means obtains a frequency characteristic of the above Symbol targets reflected signal, prompted the target radar band from the change in the signal level,
The target countermeasure device, wherein the control means switches the modulation band of the signal modulation means from the first counter signal band to the target radar band so that the target counter signal is modulated in the target radar band . 信号変調手段は、第１対抗信号帯域内で平滑な周波数特性を有する目標対抗信号を変調し、
信号分析手段は、上記第１対抗信号帯域の目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を設定し、上記レベル閾値以下のレベルを有する帯域を上記目標反射信号の周波数特性から求めて目標レーダ帯域とすることを特徴とする請求項１記載の目標対抗装置。The signal modulation means modulates a target counter signal having a smooth frequency characteristic within the first counter signal band,
The signal analysis means sets a level threshold that is lower than the level average value calculated from the frequency characteristic of the target reflected signal in the first counter signal band by a certain value, and sets a band having a level equal to or lower than the level threshold to the target reflected signal. 2. The target countermeasure apparatus according to claim 1, wherein the target radar band is obtained from the frequency characteristics of the target radar band. 信号変調手段は、第１対抗信号帯域で変調された目標対抗信号を送受信手段および信号分析手段へそれぞれ出力し、
上記信号分析手段は、上記目標対抗信号の周波数特性によって目標反射信号の正規化周波数特性を除算して目標レーダ帯域を求めることを特徴とする請求項１記載の目標対抗装置。The signal modulation unit outputs the target counter signal modulated in the first counter signal band to the transmission / reception unit and the signal analysis unit, respectively.
2. The target countermeasure apparatus according to claim 1, wherein the signal analyzing means obtains a target radar band by dividing the normalized frequency characteristic of the target reflected signal by the frequency characteristic of the target counter signal. 信号変調手段は、第１対抗信号帯域のパルス信号を変調して送受信手段および信号分析手段へそれぞれ出力するパルス変調手段を備え、
上記送受信手段は、上記パルス信号を目標へ送信するとともに、上記目標で反射した上記パルス信号である目標反射パルス信号を上記目標から受信し、
上記信号分析手段は、上記パルス信号の周波数特性によって上記目標反射パルス信号の正規化周波数特性を除算して目標レーダ帯域を求めることを特徴とする請求項１記載の目標対抗装置。The signal modulation means includes pulse modulation means for modulating the pulse signal in the first counter signal band and outputting the modulated pulse signal to the transmission / reception means and the signal analysis means,
The transmission / reception means transmits the pulse signal to the target, receives the target reflected pulse signal that is the pulse signal reflected by the target from the target,
2. The target countermeasure apparatus according to claim 1, wherein the signal analysis means obtains a target radar band by dividing the normalized frequency characteristic of the target reflected pulse signal by the frequency characteristic of the pulse signal. 信号変調手段は、第１対抗信号帯域内で平滑な周波数特性を有するＣＷ信号を変調するＣＷ変調手段を備え、
上記送受信手段は、上記第１対抗信号帯域にわたって上記ＣＷ信号を目標へスィープ送信するとともに、上記目標で反射した上記ＣＷ信号である目標反射ＣＷ信号を上記第１対抗信号帯域にわたって上記目標からスィープ受信し、
信号分析手段は、上記第１対抗信号帯域の目標反射ＣＷ信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を設定し、上記レベル閾値以下のレベルを有する帯域を上記目標反射ＣＷ信号の周波数特性から求めて目標レーダ帯域とすることを特徴とする請求項１記載の目標対抗装置。The signal modulation means includes CW modulation means for modulating a CW signal having a smooth frequency characteristic within the first counter signal band,
The transmission / reception means sweeps the CW signal to the target over the first counter signal band, and receives the target reflected CW signal, which is the CW signal reflected by the target, from the target over the first counter signal band. And
The signal analysis means sets a level threshold that is lower than the level average value calculated from the frequency characteristic of the target reflection CW signal in the first counter signal band by a certain value, and sets a band having a level equal to or lower than the level threshold to the target reflection. 2. The target countermeasure apparatus according to claim 1, wherein the target radar band is obtained from the frequency characteristics of the CW signal. 信号変調手段は、ＣＷ信号を変調して送受信手段および信号分析手段へそれぞれ出力するＣＷ変調手段を備え、
上記送受信手段は、第１対抗信号帯域内にわたって上記ＣＷ信号を目標へスィープ送信するとともに、上記目標で反射した上記ＣＷ信号である目標反射ＣＷ信号を上記第１対抗信号帯域にわたって上記目標からスィープ受信し、
信号分析手段は、上記ＣＷ信号の周波数特性によって上記目標反射ＣＷ信号の正規化周波数特性を除算して目標レーダ帯域を求めることを特徴とする請求項１記載の目標対抗装置。The signal modulation means includes CW modulation means for modulating the CW signal and outputting it to the transmission / reception means and the signal analysis means,
The transmission / reception means sweeps the CW signal to the target over the first counter signal band and receives the target reflected CW signal, which is the CW signal reflected by the target, from the target over the first counter signal band. And
2. The target countermeasure apparatus according to claim 1, wherein the signal analysis means obtains a target radar band by dividing the normalized frequency characteristic of the target reflected CW signal by the frequency characteristic of the CW signal. 信号変調手段は、第１対抗信号帯域内で平滑な周波数特性を有し、上記第１対抗信号帯域未満の狭帯域で狭帯域目標対抗信号を変調し、
上記送受信手段は、上記第１対抗信号帯域にわたって上記狭帯域目標対抗信号を目標へスィープ送信するとともに、上記目標で反射した上記狭帯域目標対抗信号である狭帯域目標反射信号を上記第１対抗信号帯域にわたって上記目標からスィープ受信し、
信号分析手段は、上記狭帯域目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を設定し、上記レベル閾値以下のレベルを有する帯域を上記狭帯域目標反射信号の周波数特性から求めて目標レーダ帯域とすることを特徴とする請求項１記載の目標対抗装置。The signal modulation means has a smooth frequency characteristic within the first counter signal band, modulates the narrow band target counter signal in a narrow band less than the first counter signal band,
The transmission / reception means sweeps the narrowband target counter signal over the first counter signal band to the target, and transmits the narrowband target reflected signal, which is the narrowband target counter signal reflected by the target, to the first counter signal. Sweep received from the above target over the bandwidth,
The signal analysis means sets a level threshold value that is lower than the level average value calculated from the frequency characteristics of the narrowband target reflected signal by a certain value, and sets a band having a level equal to or lower than the level threshold to the frequency of the narrowband target reflected signal. 2. The target countermeasure apparatus according to claim 1, wherein the target radar band is obtained from the characteristics to be a target radar band. 信号変調手段は、第１対抗信号帯域内で平滑な周波数特性を有し、上記第１対抗信号帯域未満の狭帯域で狭帯域目標対抗信号を変調して送受信手段および信号分析手段へそれぞれ出力し、
上記送受信手段は、上記第１対抗信号帯域にわたって上記狭帯域目標対抗信号を目標へスィープ送信するとともに、上記目標で反射した上記狭帯域目標対抗信号である狭帯域目標反射信号を上記第１対抗信号帯域にわたって上記目標からスィープ受信し、
上記信号分析手段は、上記狭帯域目標対抗信号の周波数特性によって上記狭帯域目標反射信号の正規化周波数特性を除算して目標レーダ帯域を求めることを特徴とする請求項１記載の目標対抗装置。The signal modulating means has a smooth frequency characteristic within the first counter signal band, modulates the narrow band target counter signal in a narrow band less than the first counter signal band, and outputs it to the transmitting / receiving means and the signal analyzing means, respectively. ,
The transmission / reception means sweeps the narrowband target counter signal over the first counter signal band to the target, and transmits the narrowband target reflected signal, which is the narrowband target counter signal reflected by the target, to the first counter signal. Sweep received from the above target over the bandwidth,
2. The target countermeasure apparatus according to claim 1, wherein the signal analyzing means obtains a target radar band by dividing a normalized frequency characteristic of the narrowband target reflected signal by a frequency characteristic of the narrowband target counter signal. 信号変調手段は、目標レーダ信号の送信帯域と第１対抗信号帯域とを一致させて目標対抗信号を変調するとともに、上記第１対抗信号帯域を上記送信帯域から順次広げて上記目標対抗信号を変調し、
信号分析手段は、上記第１対抗信号帯域の目標反射信号の周波数特性から算出されるレベル平均値より一定値だけ低いレベル閾値を設定し、上記レベル閾値以上のレベルを有する帯域を上記目標反射信号の周波数特性から求めて目標レーダ帯域とすることを特徴とする請求項１記載の目標対抗装置。The signal modulation means modulates the target counter signal by matching the transmission band of the target radar signal with the first counter signal band, and modulates the target counter signal by sequentially expanding the first counter signal band from the transmission band. And
The signal analysis means sets a level threshold that is lower than the level average value calculated from the frequency characteristic of the target reflected signal in the first counter signal band by a certain value, and sets a band having a level equal to or higher than the level threshold to the target reflected signal. 2. The target countermeasure apparatus according to claim 1, wherein the target radar band is obtained from the frequency characteristics of the target radar band. 信号変調手段は、目標レーダ信号の送信帯域と第１対抗信号帯域とを一致させて目標対抗信号を変調するとともに、上記第１対抗信号帯域を上記送信帯域から順次広げて上記目標対抗信号を変調して送受信手段および信号分析手段へそれぞれ出力し、
上記信号分析手段は、上記目標対抗信号の周波数特性によって上記目標反射信号の正規化周波数特性を除算して目標レーダ帯域を求めることを特徴とする請求項１記載の目標対抗装置。The signal modulation means modulates the target counter signal by matching the transmission band of the target radar signal with the first counter signal band, and modulates the target counter signal by sequentially expanding the first counter signal band from the transmission band. Output to the transmission / reception means and the signal analysis means,
2. The target countermeasure apparatus according to claim 1, wherein the signal analysis means obtains a target radar band by dividing the normalized frequency characteristic of the target reflected signal by the frequency characteristic of the target counter signal. 目標反射信号に含まれるドップラ周波数の変化を検出し、上記ドップラ周波数の変化に応じて対抗効果を判定する対抗効果判定処理手段と、
上記上記対抗効果判定処理手段で判定された上記対抗効果によって起動され、異なる対抗装置を新たに投入する対抗装置投入手段とを備えることを特徴とする請求項１から請求項１０記載のうちのいずれか１項記載の目標対抗装置。A counter effect determination processing means for detecting a change in Doppler frequency included in the target reflection signal and determining a counter effect according to the change in the Doppler frequency;
11. The apparatus according to claim 1, further comprising: a counter device input unit that is activated by the counter effect determined by the counter effect determination processing unit and newly inputs a different counter device. A target countermeasure device according to claim 1. 対抗効果判定処理手段は、ドップラ周波数が低い方に変化した場合に対抗効果を高いと判定することを特徴とする請求項１１記載の目標対抗装置。12. The target countermeasure apparatus according to claim 11, wherein the counter effect determination processing means determines that the counter effect is high when the Doppler frequency changes to a lower one. 対抗効果判定処理手段は、ドップラ周波数が変化していない場合に対抗効果を低いと判定することを特徴とする請求項１１記載の目標対抗装置。12. The target countermeasure apparatus according to claim 11, wherein the counter effect determination processing means determines that the counter effect is low when the Doppler frequency does not change. 信号分析手段で検出された目標レーダ帯域を与えられ、上記目標レーダ帯域外においてレーダ信号を目標へ送信するレーダ装置を備えることを特徴とする請求項１から請求項１１のうちのいずれか１項記載の目標対抗装置。The radar apparatus according to any one of claims 1 to 11, further comprising a radar device that is provided with a target radar band detected by the signal analysis means and transmits a radar signal to the target outside the target radar band. The listed target combat device.
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