JP3866048B2 - Image radar device - Google Patents

Description

【００３６】
ただし、Ｔはベクトルの転置演算を表す。
これを各点Ｐｊごとにまとめると次式が得られる。
【００３７】
【数２】

【００３８】
ただし、ｓｓｎｘ，ｓｓｎｙ，ｓｓｎｚ（ｎ＝１，２，３）はベクトルｓｓｎの第一要素、第二要素、第三要素を表す。式（２）を変形すると次式が得られる。
【００３９】
【数３】

【００４０】
３次元形状復元回路１３では、式（３）に基づき点Ｐｊの３次元の位置ベクトルを算出し、その位置に点を配置する。
各点ごとに同じ処理を行うことで、観測目標に関して、その３次元形状を点の分布として得ることができる。
【００４１】
このような構成の画像レーダ装置においては、目標の３次元形状を知ることができるので識別性能が向上する。
【００４２】
実施の形態２．
図５は本発明の画像レーダ装置の実施の形態２を示すの処理ブロック図である。図において、２１は反射強度３次元分布構築回路である。
【００４３】
次に、図５を用いて、本実施の形態の処理内容を説明する。
本実施の形態では実施の形態１における３次元形状復元回路１３の出力である各反射点の位置に対して各レーダ画像収集装置１１で得られたＩＳＡＲ画像より反射強度を与える。
【００４４】
すなわち、反射強度３次元分布構築回路２１では、各レーダ画像収集装置１１で得られたＩＳＡＲ画像ｉｍａｇｅ＃１，ｉｍａｇｅ＃２，ｉｍａｇｅ＃３ごとに、それぞれ３次元形状復元回路１３で得られた各反射点の３次元座標に反射点Ｐｊの反射強度を割り当てる。こうして得られた３次元の反射強度分布は、目標を各レーダ画像収集装置１１方向から観測した場合の目標上の反射強度分布に対応する。
【００４５】
このような構成の画像レーダ装置においては、目標の３次元形状を知ることができるので識別性能が向上する。
また、目標の３次元反射強度分布を知ることができるので識別性能が向上する。
【００４６】
実施の形態３．
図６は本発明の画像レーダ装置の実施の形態３を示すの処理ブロック図である。図において、３１は強度考慮対応点判定回路である。
【００４７】
次に、図６を用いて本実施の形態の処理内容を説明する。
本実施の形態では、レーダ画像収集装置１１で得られた反射強度分布まで用いて各ｉｍａｇｅ＃ｎ間の反射点の対応づけを行う。
【００４８】
強度考慮対応点判定回路３１では、各画像における反射点の強度の情報を踏まえて、反射点の対応づけを行う。これは、例えば、レーダ画像収集装置１１からみた目標の方向が類似する場合には、同じ反射点の反射強度は近い値をとることを利用している。
【００４９】
このような構成の画像レーダ装置においては、目標の３次元形状を知ることができるので識別性能が向上する。
また、目標の３次元反射強度分布を知ることができるので識別性能が向上する。
さらには、反射強度を利用して３次元形状を構築するので、３次元形状の構築精度が向上する。
【００５０】
実施の形態４．
図７は本発明の画像レーダ装置の実施の形態４を示すの処理ブロック図である。図において、４１はＮ画像対応点判定回路である。図８は本実施の形態の処理を説明するための図である。
【００５１】
次に図７、図８を用いて本実施の形態の処理内容を説明する。
実施の形態１では、異なる位置に配置された３台のレーダ画像収集装置１１で得られたＩＳＡＲ画像ｉｍａｇｅ＃１，ｉｍａｇｅ＃２，ｉｍａｇｅ＃３を用いて観測目標の３次元形状を復元した。
【００５２】
しかし、これを行う場合には反射点が上記３枚の画像で対応がとれている必要がある。しかし、反射点の位置、反射特性等によってはいずれかの画像で検出されない可能性がある。そこで３台以上のＮ台のレーダ画像収集装置１１を用意し、ＩＳＡＲ画像ｉｍａｇｅ＃１〜ｉｍａｇｅ＃Ｎを得る。
【００５３】
Ｎ画像対応点判定回路４１では、これらＮ枚の画像から各反射点ごとに反射点を確認できる３枚の画像を各反射点ごとに選びだす。これに対して３次元形状復元回路１３では、実施の形態１同様式（３）を適用して３次元の位置ベクトルを得る。
【００５４】
このような構成の画像レーダ装置においては、目標の３次元形状を知ることができるので識別性能が向上する。
また、多数の枚数の画像を用いて３次元形状を構築するので例えば、３枚の画像では、反射点がある画像で見えないとき、３台のレーダ画像収集装置ではそのレンジベクトルが一次独立ではない場合にも対応できる。
【００５５】
実施の形態５．
図９は本発明の画像レーダ装置の実施の形態５を示すの処理ブロック図である。図において、５１は基準点選定回路、５２は基準位置推定回路、５３は回転角速度ベクトル推定回路、５４は回転軸位置推定回路、５５は回転運動推定回路を表す。図１０は本実施の形態の処理内容を説明するための図である。
【００５６】
次に図９、図１０を用いて本実施の形態の処理内容を説明する。
３台のレーダ画像収集装置１１でレーダ画像ｉｍａｇｅ＃１，ｉｍａｇｅ＃２，ｉｍａｇｅ＃３を得る。
基準点選定回路５１では、目標上の４点Ｐ０〜Ｐ３を選び出す。
【００５７】
基準位置推定回路５２では、各ｉｍａｇｅ＃ｎ上での反射点Ｐ０を基準とした各反射点Ｐｍの距離ｓｎｍ（ｎ＝１，２，３；ｍ＝１，２，３）を得る。さらに、各レーダ画像収集装置１１のレンジベクトルｓｓｎを用いて式（３）でＰ０を基準とした３次元位置ベクトルを得る。
【００５８】
回転角速度ベクトル推定回路５３では、ｉｍａｇｅ＃ｎにおいてＰ０を基準とした各反射点Ｐｍのドップラー周波数ｆｎｍを得て次式でＰ０を基準とした各反射点Ｐｍの相対速度ｖｎｍを得る。
【００５９】
【数４】

【００６０】
ただし、λは送信波長である。ｖｎｍとｓｓｎ、ｒｒｍ、回転角速度ベクトルＬＬの間には次式の関係がある。
【００６１】
【数５】

【００６２】
ただし、ＡＡ、ＢＢをベクトルとすると（ＡＡ・ＢＢ）はＡＡとＢＢの内積演算、（ＡＡ×ＢＢ）はＡＡとＢＢの外積演算を表す。
さてここで、ｎ，ｍを変化させた場合のベクトルｒｒｍ×ｓｓｎは９種類になる。これらのうちから、一次独立な３種類のベクトルを選びだし、これをｇｇｋ（ｋ＝１，２，３）とし、そのベクトルに対応する相対速度をｖｋとすると、次式が成立する。
【００６３】
【数６】

【００６４】
ただし、ｇｇｋｘ，ｇｇｋｙ，ｇｇｋｚ（ｋ＝１，２，３）はベクトルｇｇｋの第一、第二、第三要素である。よってＬＬは、次式で与えられる。
【００６５】
【数７】

【００６６】
すなわち、目標の回転運動を表す角速度ベクトルが定まった。
【００６７】
このような構成の画像レーダ装置においては、目標の回転運動を表す角速度ベクトルを得ることができるのでこの値を用いた識別が行えるようになる。
【００６８】
なお、本実施の形態においてレーダ画像収集装置の台数を３としたが、３台以上としても成立するのは言うまでもない。
【００６９】
実施の形態６．
図１１は本発明の画像レーダ装置の実施の形態６を示すの処理ブロック図である。図において、６１は回転運動履歴蓄積回路である。
【００７０】
次に図１１を用いて本実施の形態の処理内容を説明する。
レーダ画像収集装置１１で得られた３枚のＩＳＡＲ画像を用いて回転運動推定回路５５で回転角速度ベクトルＬＬを推定する処理は実施の形態５と同様である。本実施の形態では、この回転角速度ベクトルを回転運動履歴蓄積回路６１に蓄積する。
【００７１】
このような構成の画像レーダ装置においては、目標の回転運動を表す角速度ベクトルの時間変化を得ることができるので、例えば、Ｐｉｔｃｈ運動の周期のような運動情報を得ることができる。
【００７２】
実施の形態７．
図１２は本発明の画像レーダ装置の実施の形態７を示すの処理ブロック図である。図において、７１は投影面決定回路、７２はレンジ・クロスレンジ画像生成回路である。
【００７３】
次に図１２を用いて本実施の形態の処理内容を説明する。
本実施の形態では実施の形態５の回転運動推定回路５５で得られた角速度ベクトルＬＬを用いて、まず投影面決定回路７１で、各レーダ画像収集装置１１ごとの目標形状の投影面を決定する。目標上の反射点ＰｍのＰ０を基準とした位置ベクトルをｒｒｍとし、そのＩＳＡＲ画像上でのＰ０を基準としたレンジ、ドップラー周波数をｓｎｍ，ｆｎｍとすると、これらの変数の間には次式が成立する。
【００７４】
【数８】

【００７５】
【数９】

【００７６】
ここで、次式を満足するベクトルｃｃｎを導入する。
【００７７】
【数１０】

【００７８】
このｃｃｎはベクトルｓｓｎ×ＬＬと同じ方向の単位ベクトルであり、以下ではクロスレンジベクトルと呼ぶ。
式（８）（１０）より、空間中でｓｓｎとｃｃｎで定義された平面が、目標形状を投影する投影面である。なお式（９）（１０）の関係より次式が成立する。
【００７９】
【数１１】

【００８０】
ここで、右辺が反射点Ｐｍの位置ベクトルｒｒｍとｃｃｎの内積であることから左辺はｒｒｍのｃｃｎ方向への射影成分を表している事となる。このことを踏まえて、レンジ・クロスレンジ画像生成回路７２では収集したＩＳＡＲ画像ｉｍａｇｅ＃ｎ（ｎ＝１，２，３）を周波数方向に、−λ／（２｜｜ｓｓｎ×ＬＬ｜｜）倍する。
【００８１】
これにより、ｓｓｎ，ｃｃｎ方向ともに距離軸とするレンジクロスレンジ画像を得る。この時のクロスレンジ方向の長さをｃｎｍとする。
【００８２】
このような構成の画像レーダ装置においては、目標に関して各レーダ画像収集装置ごとにレンジ、およびそれに直交したクロスレンジ方向の長さを軸とした目標画像を得ることができるので、これを用いて目標識別性能を向上させることができる。
【００８３】
実施の形態８．
図１３は本発明の画像レーダ装置の実施の形態８を示すの処理ブロック図である。図において、８１は直線交差判定回路、８２は交差情報考慮型対応点判定回路である。
【００８４】
次に図１３を用いて本実施の形態の処理内容を説明する。
本実施の形態では、レンジ・クロスレンジ画像生成回路７２までの処理で、各レーダ画像収集装置１１ごとの投影面を決定するレンジベクトルｓｓｎ（ｎ＝１，２，３）、クロスレンジベクトルｃｃｎ（ｎ＝１，２，３）および、各ｉｍａｇｅ＃ｎ上の反射点の座標ｓｎｐ，ｃｎｐを用いて、３枚の画像上の反射点の対応づけを行った上で３次元形状を構築する。
【００８５】
直線交差判定回路８１では、まず、各レーダ画像収集装置１１ごとの投影面の法線ベクトルｔｔｎを次式で得る。
【００８６】
【数１２】

【００８７】
反射点Ｐを各投影面ｎへ投影した場合の位置ベクトルをｕｕｐｎとすると、ｕｕｐｎは次式で与えられる。
【００８８】
【数１３】

【００８９】
反射点Ｐはｕｕｐｎを通りｔｔｎ方向の軸上に存在する。
さて、面ｎａとｎｂで同一の点が観測された場合、上記の軸はある１点で交わる。よって、上記の軸が交わるかどうかを判定して、交わった場合には同一の反射点の組合わせの候補とする。軸が交わるかどうかの判定は、次式で行う。
【００９０】
【数１４】

【００９１】
上式のａが０の場合には２本の軸が交わる。それ以外の場合には２本の軸はねじれの位置にある。
【００９２】
直線交差判定回路８１では以上の情報をもとに各面上の反射点を通る軸間の交差を判定する。
【００９３】
交差情報考慮型対応点判定回路８２では、直線交差判定回路８１の情報を元に、上記の軸が同じ１点を通る各面上の点の組合わせを判定する。
３次元形状復元回路１３では交差情報考慮型対応点判定回路８２で得られた組合わせの情報を元に実施の形態１等と同じ方式で３次元形状を復元する。
【００９４】
このような構成の画像レーダ装置においては、目標に関して、軸の交差情報を利用して３次元形状を構築するので、３次元形状構築の精度が向上し、識別性能が向上する。
【００９５】
実施の形態９．
図１４は本発明の画像レーダ装置の実施の形態９を示すの処理ブロック図である。図において、９１は交点探索回路、９２は交点通過型対応点判定回路である。
【００９６】
次に図１４を用いて本実施の形態の処理内容を説明する。
実施の形態８と同様の処理で、ｉｍａｇｅ＃１〜ｉｍａｇｅ＃３のうちの２枚ｉｍａｇｅ＃ｎａ，ｉｍａｇｅ＃ｎｂの画像上の反射点が交差するかどうかを判定する。
【００９７】
交差していると判定されたｉｍａｇｅ＃ｎａ，ｉｍａｇｅ＃ｎｂ上の反射点の画像上での位置ベクトルをｒｒｎａｐ、ｒｒｎｂｐとすると交点の位置ベクトルｒｒｒは次式で与えられる。
【００９８】
【数１５】

【００９９】
ここで、α，βは未知数である。さて、ｔｔｎａ，ｔｔｎｂはいずれも３次元ベクトルであるが、このうちの２要素（たとえば第一要素と第二要素）を適当に選ぶ事で２次元ベクトルを生成できる。ｔｔｎａ，ｔｔｎｂで同じ２要素を選んで２次元ベクトルを生成する。これを（ｔｘａ，ｔｙａ），（ｔｘｂ，ｔｙｂ）とする。ただし、これらの２次元ベクトルとして互いに一次独立な組を選択する。また同じ要素に関してｒｒｎａｐ、ｒｒｎｂｐから生成した２次元ベクトルをそれぞれ（ｒｘａ，ｒｙａ），（ｒｘｂ，ｒｙｂ）とする。なお、これらの２次元ベクトルはいずれも列ベクトルで以下考える。
α、βは次式で定まる。
【０１００】
【数１６】

【０１０１】
よって、式（１５）のｒｒｒが定まる。
交点探索回路９１では上記の処理を行う。
【０１０２】
さて、ｉｍａｇｅ＃１〜ｉｍａｇｅ＃３のうちの残りの１枚ｉｍａｇｅ＃ｎｃ上で上記位置ベクトルｒｒｒの反射点に対応する点ｒｒｎｃｐが存在した場合、次式が成立する。
【０１０３】
【数１７】

【０１０４】
ここで、γは適当な定数である。よって、ｉｍａｇｅ＃ｎａ，ｉｍａｇｅ＃ｎｂ上の各反射点間で求まった各交点とｉｍａｇｅ＃ｎｃ上の各反射点に関して、式（１７）を適用し、これを満足する組が存在した場合には、上記の交点に関連する各画像上の反射点と、ｉｍａｇｅ＃ｎｃ上のこの反射点の対応がとれたと判定できる。
【０１０５】
交点通過型対応点判定回路９２は、上記の性質を踏まえて、各反射点間の対応を判定する。３次元形状復元回路１３ではこの結果を踏まえて３次元形状を復元する。
【０１０６】
このような構成の画像レーダ装置においては、軸の交差情報を利用して３次元形状を構築するので、３次元形状構築の精度が向上し、識別性能が向上する。
【０１０７】
実施の形態１０．
図１５は本発明の画像レーダ装置の実施の形態１０を示すの処理ブロック図である。図において、１０１は３次元形状照合回路である。
【０１０８】
次に図１５を用いて本実施の形態の処理内容を説明する。
３次元形状復元回路１３までの処理で観測目標の３次元形状を構築する処理は実施の形態１と同様である。３次元形状照合回路１０１では、目標形状データ蓄積手段５１２に蓄積された各候補目標の３次元形状と３次元形状復元回路１３で構築された観測目標の３次元形状を照合する。照合した結果最も一致すると判定された候補目標を観測目標の識別結果として出力する。
【０１０９】
このような構成の画像レーダ装置においては、観測目標の種類を３次元形状を用いて識別できるので識別性能が向上する。
【０１１０】
実施の形態１１．
図１６は本発明の画像レーダ装置の実施の形態１１を示すの処理ブロック図である。図において、１１１は反射強度３次元分布照合回路である。
【０１１１】
次に図１６を用いて本実施の形態の処理内容を説明する。
反射強度３次元分布構築回路２１までの処理で観測目標の反射強度３次元分布を得る処理は実施の形態２と同様である。
反射強度３次元分布照合回路１１１では、観測目標の反射強度３次元分布と目標形状データ蓄積手段５１２に蓄積された各候補目標の３次元形状にＲＣＳ算出手段５１０を適用して得られた候補目標の反射強度３次元分布を照合して、その種類を識別する。
【０１１２】
このような構成の画像レーダ装置においては、観測目標の種類を３次元の反射強度分布を用いて識別できるので識別性能が向上する。
【０１１３】
実施の形態１２．
図１７は本発明の画像レーダ装置の実施の形態１２を示すの処理ブロック図である。図において、１２１は受信専用画像収集装置である。図１８は図１７の受信専用画像収集装置１２１を詳細に示す処理ブロック図である。図において、１２２はバイスタレンジベクトル算出手段である。
【０１１４】
次に図１７、図１８を用いて本実施の形態の処理内容を説明する。
本実施の形態では、１機のレーダ画像収集装置１１と、２機の受信専用レーダ画像収集装置１２１で得られたレーダ画像を用いて目標の３次元形状を構築する。受信専用レーダ画像収集装置１２１では、レーダ画像収集装置１１から照射されて、目標で散乱された電波を受信アンテナ５０３を介して受信機５０４で受信してレーダ画像再生手段５０５でレーダ画像を再生する。
【０１１５】
バイスタレンジベクトル算出手段１２２では、反射波の到来方向およびレーダ画像収集装置１１から目標への照射方向から、バイスタティック構成におけるレンジベクトルを計算する。
以下、対応点判定回路１２、３次元形状復元回路１３での処理は実施の形態１と同様である。
【０１１６】
本実施の形態では、実施の形態１と同等の効果を、より簡単な構成で実現できる。
【０１１７】
実施の形態１３．
図１９は本発明の画像レーダ装置の実施の形態１３を示すの処理ブロック図である。図において、１３１は回転運動蓄積手段、１３２は回転運動照合回路である。
【０１１８】
次に図１９を用いて本実施の形態の処理内容を説明する。
本実施の形態では、実施の形態６と同様の処理で回転運動履歴蓄積回路６１に蓄積された目標の回転運動履歴を、事前に回転運動蓄積手段１３１に蓄積された候補目標の回転運動履歴（例えばｙａｗ、ｒｏｌｌ、ｐｉｔｃｈ運動の周期や振幅等）と比較して、その回転運動が類似する候補目標を目標の識別結果とする。
【０１１９】
このような構成の画像レーダ装置においては、各目標ごとに固有の運動情報を用いて識別を行うので識別性能が向上する。
【０１２０】
実施の形態１４．
図２０は本発明の画像レーダ装置の実施の形態１４を示すの処理ブロック図である。図において、１３１は移動レーダ画像収集装置である。図２１は図２０の移動レーダ画像収集装置１３１を詳細に示すの処理ブロック図である。図において、１３２はレーダ画像履歴蓄積手段、１３３はレンジベクトル履歴蓄積手段である。図２２は本実施の形態の処理内容を説明するための図である。
【０１２１】
次に図２０、図２１、図２２を用いて、本実施の形態の処理内容を説明する。
本実施の形態では、移動レーダ画像収集装置が、ｔ＝ｔ１，ｔ２，ｔ３と時刻が進むにつれ場所を移動しながら目標の観測を行う場合を想定する。
【０１２２】
移動レーダ画像収集装置１３１ではレーダ画像再生手段５０５、および、レンジベクトル算出手段１４までの処理は実施の形態１に示したレーダ画像収集装置１１と同様である。移動レーダ画像収集装置１３１ではレーダ画像再生手段の後段にレーダ画像履歴蓄積手段１３２を配置し、各時刻ｔｎにおけるレーダ画像ｒａｄａｒ＃ｎを蓄積する。また、レンジベクトル算出手段１４の後段にレンジベクトル履歴蓄積手段１３３を配置し、各時刻ｔｎにおけるレンジベクトルｓｓｎを蓄積する。以降対応点判定回路１２で各画像間の対応関係を判定し、３次元形状復元回路１３で、３次元形状を復元する処理は実施の形態１と同様である。
【０１２３】
すなわち、本実施の形態では、少ない台数のレーダ画像収集装置で実施の形態１と同じ効果を得れる利点がある。
【０１２４】
【発明の効果】
この発明に係るレーダ装置においては、目標に電波を照射し、目標からの反射波を利用して目標の形状情報をＩＳＡＲレーダ画像として得る画像レーダ装置であって、異なる位置に配置され目標のレーダ画像の収集およびレーダ位置を基準とした目標の存在方向の推定を行う複数のレーダ画像収集装置と、各レーダ画像収集装置の出力画像上の各反射点間の対応を判定する対応点判定回路と、対応点判定回路の出力である対応点の判定結果と各レーダ画像収集装置の出力であるレーダ画像および目標の存在方向とからそれぞれの画像における各反射点のレンジを抽出し、抽出した上記各反射点のレンジを組み合わせて目標の３次元形状を復元する３次元形状復元回路とを備えている。そのため、目標の３次元形状を知ることができ、識別性能を向上させることができる。
【０１２５】
また、この発明に係るレーダ装置においては、目標に電波を照射し、目標からの反射波を利用して目標の形状情報をＩＳＡＲレーダ画像として得る画像レーダ装置であって、異なる位置に配置され目標のレーダ画像の収集およびレーダ位置を基準とした目標の存在方向の推定を行う複数のレーダ画像収集装置と、各レーダ画像収集装置の出力画像上の各反射点間の対応を判定する対応点判定回路と、対応点判定回路の出力である対応点の判定結果と各レーダ画像収集装置の出力であるレーダ画像から得られるそれぞれの画像における各反射点のレンジおよび目標の存在方向とから目標上の反射強度に関する３次元分布を構築する反射強度３次元分布構築回路とを備えている。そのため、目標の３次元形状を知ることができ、識別性能を向上させることができるとともに、目標の３次元反射強度分布を知ることができるのでさらに識別性能が向上する。
【０１２６】
また、この発明に係るレーダ装置においては、目標に電波を照射し、目標からの反射波を利用して目標の形状情報をＩＳＡＲレーダ画像として得る画像レーダ装置であって、異なる位置に配置され目標のレーダ画像の収集およびレーダ位置を基準とした目標の存在方向の推定を行う複数のレーダ画像収集装置と、各レーダ画像収集装置の出力画像上の各反射点間の対応を、各反射点の振幅値情報をも用いて判定する強度考慮対応点判定回路と、強度考慮対応点判定回路の出力である対応点の判定結果と各レーダ画像収集装置の出力であるレーダ画像から得られるそれぞれの画像における各反射点のレンジおよび目標の存在方向とから目標の３次元形状を復元する３次元形状復元回路とを備えている。そのため、目標の３次元形状を知ることができ、識別性能を向上させることができるとともに、目標の３次元反射強度分布を知ることができるので識別性能が向上する。さらには、反射強度を利用して３次元形状を構築するので、３次元形状の構築精度が向上する。
【０１２７】
また、この発明に係るレーダ装置においては、目標に電波を照射し、目標からの反射波を利用して目標の形状情報をＩＳＡＲレーダ画像として得る画像レーダ装置であって、異なる位置に配置され目標のレーダ画像の収集およびレーダ位置を基準とした目標の存在方向の推定を行う複数のレーダ画像収集装置と、各レーダ画像収集装置の出力画像上の各反射点間を、各反射点毎に、多数の画像のうちいずれか３枚を用いて対応づけるＮ画像対応点判定回路と、Ｎ画像対応点判定回路の出力である対応点の判定結果と各レーダ画像収集装置の出力であるレーダ画像から得られるそれぞれの画像における各反射点のレンジおよび目標の存在方向とから目標の３次元形状を復元する３次元形状復元回路とを備えている。そのため、目標の３次元形状を知ることができるので識別性能が向上し、また、多数の枚数の画像を用いて３次元形状を構築するので例えば、３枚の画像では、反射点がある画像で見えないとき、３台のレーダ画像収集装置ではそのレンジベクトルが一次独立ではない場合にも対応できる。
【０１２８】
また、この発明に係るレーダ装置においては、目標に電波を照射し、目標からの反射波を利用して目標の形状情報をＩＳＡＲレーダ画像として得る画像レーダ装置であって、異なる位置に配置され目標のレーダ画像の収集およびレーダ位置を基準とした目標の存在方向の推定を行う複数のレーダ画像収集装置と、各レーダ画像収集装置の出力画像上の各反射点間のうち対応のとれる基準点を選定する基準点選定回路、基準点選定回路で得られた基準点に関してその空間位置を推定する基準位置推定回路、基準位置推定回路で得られた基準点の空間位置とレーダ画像収集装置で得られた各基準点の画像の画像上のレンジおよびドップラー周波数と各レーダ画像収集装置の位置を基準とした目標の方向とから目標の回転角速度ベクトルを推定する回転角速度ベクトル推定回路、および回転軸の位置を推定する回転軸位置推定回路を有する回転運動推定回路とを備えている。そのため、目標の回転運動を表す角速度ベクトルを得ることができるのでこの値を用いた識別が行えるようになり、さらに識別性能が向上する。
【０１２９】
また、回転運動推定回路の出力である回転運動の推定結果を各時刻で蓄積する回転運動履歴蓄積回路をさらに備えている。これにより、目標の回転運動を表す角速度ベクトルの時間変化を得ることができるので、例えばＰｉｔｃｈ運動の周期のような運動情報を得ることができる。
【０１３０】
また、回転運動推定回路の推定結果を基に各レーダ画像収集装置ごとのクロスレンジ軸と長さと周波数のスケーリングを推定する投影面決定回路と、投影面決定回路の推定結果を基に、レンジおよびレンジに直交するクロスレンジを長さで表現したレーダ画像を各レーダ画像収集装置ごとに得られたレーダ画像に関して生成するレンジ・クロスレンジ画像生成回路とをさらに備えている。そのため、目標に関して各レーダ画像収集装置ごとにレンジ、およびそれに直交したクロスレンジ方向の長さを軸とした目標画像を得ることができるので、これを用いて目標識別性能を向上させることができる。
【０１３１】
また、各レンジクロスレンジ画像生成回路上の各反射点ごとに、各反射点の存在範囲をそのレンジクロスレンジ画像上の反射点を通り、その平面に直交する直線上に限定し、各レンジクロスレンジ画像毎に現れる各軸が交わるか否かを判定する直線交差判定回路と、直線交差判定回路で得られた交差情報を基に、各面上の点に関する軸が全面で１点で交わるものを探索し、これに基づいて対応点を決定する交差情報考慮型対応点判定回路と、交差情報考慮型対応点判定回路の情報を基に目標の３次元形状を構築する３次元形状構築回路とをさらに備えている。そのため、目標に関して、軸の交差情報を利用して３次元形状を構築するので、３次元形状構築の精度が向上し、識別性能が向上する。
【０１３２】
また、各レンジクロスレンジ画像生成回路上の各反射点ごとに、各反射点の存在範囲をそのレンジクロスレンジ画像上の反射点を通り、その平面に直交する直線上に限定し、各レンジクロスレンジ画像ごとに現れる各軸が交わる否かを判定する直線交差判定回路と、交差していると判定された点の組に関して交点の３次元座標を決定する交点探索回路と、さらに別のレンジクロスレンジ画像に関して、各反射点ごとに軸を決定し、その軸が交点を通過するかどうかを調べ、通過した場合にはその点、および交点に関する各画像上の点の組を対応している、そうでなければ対応していないと判定する交点通過型対応点判定回路と、交点通過型対応点判定回路の情報を基に目標の３次元形状を構築する３次元形状構築回路とをさらに備えている。そのため、目標に関して、軸の交差情報を利用して３次元形状を構築するので、３次元形状構築の精度が向上し、識別性能が向上する。
【０１３３】
また、候補目標の形状データを蓄積する目標形状データ蓄積手段と、３次元形状復元回路で復元された観測目標の３次元形状と目標形状データ蓄積手段に蓄積された候補目標の形状データを照合して、類似している候補目標を出力する３次元形状照合回路とをさらに備えている。そのため、観測目標の種類を３次元形状を用いて識別でき、識別性能が向上する。
【０１３４】
また、候補目標の形状データを蓄積する目標形状データ蓄積手段と、目標形状データに蓄積された各候補目標の３次元形状データに電磁界理論を適用して、その反射強度の３次元分布を算出するＲＣＳ算出手段と、反射強度３次元分布構築回路で構築された観測目標の反射強度の３次元分布とＲＣＳ算出手段で得られた各候補目標の反射強度の３次元分布を照合して類似する候補目標を選択する反射強度３次元分布照合回路とをさらに備えている。そのため、観測目標の種類を３次元の反射強度分布を用いて識別でき、識別性能が向上する。
【０１３５】
また、この発明に係るレーダ装置においては、目標に電波を照射し、目標からの反射波を利用して目標の形状情報をＩＳＡＲレーダ画像として得る画像レーダ装置であって、異なる位置に配置して、目標に対して電波の送受信を行い、目標のレーダ画像の収集、およびレーダ位置を基準とした目標の存在方向の推定を行うレーダ画像収集装置と、所定のレーダ画像収集装置から目標に照射して反射された信号を用いて目標のレーダ画像とレーダ画像に関するレンジベクトルを得る受信専用レーダ画像収集装置と、レーダ画像収集装置または受信専用レーダ画像収集装置より得られた出力画像上の各反射点間の対応を判定する対応点判定回路と、対応点判定回路の出力である対応点の判定結果と各レーダ画像収集装置または受信専用レーダ画像収集装置の出力であるレーダ画像および目標の存在方向から目標の３次元形状を復元する３次元形状復元回路とを備えている。そのため、レーダ装置をより簡単な構成で実現でき、コストダウンを図ることができる。
【０１３６】
また、各候補目標ごとの回転運動情報を蓄積する回転運動蓄積手段と、回転運動履歴蓄積回路に蓄積された各時刻ごとの観測目標の回転運動の履歴と回転運動蓄積手段に蓄積した各候補目標ごとの回転運動情報を照合して、回転運動が類似する候補目標を出力する回転運動照合回路とをさらに備えている。このような構成においては、各目標ごとに固有の運動情報を用いて識別を行うので識別性能が向上する。
【０１３７】
また、レーダ画像収集装置は、目標に照射する高周波パルスを生成する送信機と、送信機で生成された高周波パルスを送受信する送受信アンテナと、目標により反射、散乱された高周波パルスの一部を送受信アンテナを介して受信・検波する受信機と、受信機で得られた受信信号を元に観測対象のレーダ画像を生成するレーダ画像再生手段と、受信信号の到来方向からレーダ画像収集装置の位置を基準とした目標の存在方向を単位ベクトルで得るレンジベクトル算出手段とを有する。そのため、反射波の到来方向をもとに、レーダ画像収集装置から見た目標方向の単位ベクトル、すなわち、レンジベクトルを得ることができる。
【０１３８】
また、レーダ画像収集装置は、目標により反射、散乱された高周波パルスの一部を送受信アンテナを介して受信・検波する受信機と、受信機で得られた受信信号を元に観測対象のレーダ画像を生成するレーダ画像再生手段と、受信信号の到来方向および、その受信信号を得るための送信を行ったレーダ画像収集装置の照射方向から、レンジ方向の単位ベクトルを推定するバイスタレンジベクトル算出手段とを有する。そのため、反射波の到来方向およびレーダ画像収集装置から目標への照射方向に基づいて、バイスタティック構成におけるレンジベクトルを計算することができる。
【０１３９】
また、この発明に係るレーダ装置においては、目標に照射する高周波パルスを生成する送信機、送信機で生成された高周波パルスを送受信する送受信アンテナ、目標により反射、散乱された高周波パルスの一部を送受信アンテナを介して受信・検波する受信機、受信機で得られた受信信号を基に観測対象のレーダ画像をＩＳＡＲレーダ画像として生成するレーダ画像再生手段、受信信号の到来方向から目標の存在方向を単位ベクトルで得るレンジベクトル算出手段、レーダと目標の相対運動により刻一刻と変化するレーダ画像再生手段の出力であるレーダ画像を蓄積するレーダ画像履歴蓄積手段、およびレーダと目標の相対運動により刻一刻と変化するレンジベクトル算出手段の出力であるレンジベクトルの算出結果を蓄積するレンジベクトル履歴蓄積手段を有する移動レーダ画像収集装置と、移動レーダ画像収集装置の出力である各時刻におけるレーダ画像から対応点を決定する対応点判定回路と、対応点判定回路の対応点判定結果と移動レーダ画像収集装置の出力であるレンジベクトルの履歴およびレーダ画像の履歴から目標の３次元形状を復元する３次元形状復元回路とを備えている。そのため、少ない台数のレーダ画像収集装置で同様の効果を得れる利点がある。
【図面の簡単な説明】
【図１】 本発明の画像レーダ装置の実施の形態１を示すの処理ブロック図である。
【図２】 図１のレーダ画像収集装置を詳細に示す処理ブロック図である。
【図３】 実施の形態１の処理を説明するためのジオメトリである。
【図４】 各レーダ画像収集装置で得られるＩＳＡＲ画像の例である。
【図５】 本発明の画像レーダ装置の実施の形態２を示すの処理ブロック図である。
【図６】 本発明の画像レーダ装置の実施の形態３を示すの処理ブロック図である。
【図７】 本発明の画像レーダ装置の実施の形態４を示すの処理ブロック図である。
【図８】 実施の形態４の処理を説明するための図である。
【図９】 本発明の画像レーダ装置の実施の形態５を示すの処理ブロック図である。
【図１０】 実施の形態５の処理内容を説明するための図である。
【図１１】 本発明の画像レーダ装置の実施の形態６を示すの処理ブロック図である。
【図１２】 本発明の画像レーダ装置の実施の形態７を示すの処理ブロック図である。
【図１３】 本発明の画像レーダ装置の実施の形態８を示すの処理ブロック図である。
【図１４】 本発明の画像レーダ装置の実施の形態９を示すの処理ブロック図である。
【図１５】 本発明の画像レーダ装置の実施の形態１０を示すの処理ブロック図である。
【図１６】 本発明の画像レーダ装置の実施の形態１１を示すの処理ブロック図である。
【図１７】 本発明の画像レーダ装置の実施の形態１２を示すの処理ブロック図である。
【図１８】 図１７の受信専用画像収集装置を詳細に示す処理ブロック図である。
【図１９】 本発明の画像レーダ装置の実施の形態１３を示すの処理ブロック図である。
【図２０】 本発明の画像レーダ装置の実施の形態１４を示すの処理ブロック図である。
【図２１】 図２０の移動レーダ画像収集装置を詳細に示すの処理ブロック図である。
【図２２】 実施の形態１４の処理内容を説明するための図である。
【図２３】 従来のレーダ装置の構成を示す図である。
【図２４】 観測時の目標とレーダとの位置関係および目標の運動を示す図である。
【図２５】 図２３で示したレーダ画像再生手段の内部を詳細に示したものである。
【図２６】 図２３で示したレーダ画像表示手段の内部を詳細に示したものである。
【符号の説明】
１１ レーダ画像収集装置、１２ 対応点判定回路、１３ ３次元形状復元回路、２１ 反射強度３次元分布構築回路、３１ 強度考慮対応点判定回路、４１Ｎ画像対応点判定回路、５１ 基準点選定回路、５２ 基準位置推定回路、５３ 回転角速度ベクトル推定回路、５４ 回転軸位置推定回路、５５ 回転運動推定回路、６１ 回転運動履歴蓄積回路、７１ 投影面決定回路、７２ レンジ・クロスレンジ画像生成回路、８１ 直線交差判定回路、８２ 交差情報考慮型対応点判定回路、９１ 交点探索回路、９２ 交点通過型対応点判定回路、５１２ 目標形状データ蓄積手段、１０１ ３次元形状照合回路、５１０ ＲＣＳ算出手段、１１１ 反射強度３次元分布照合回路、１２１ 受信専用レーダ画像収集装置、１３１ 回転運動蓄積手段、１３２ 回転運動照合回路、５０１ 送信機、５０３ 送受信アンテナ、５０４ 受信機、５０５ レーダ画像再生手段、１４ レンジベクトル算出手段、１２２ バイスタレンジベクトル算出手段、１３２ レーダ画像履歴蓄積手段、１３１ 移動レーダ画像収集装置[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image radar apparatus that recognizes and identifies a target using a radar image, and more particularly to an image radar apparatus that can improve identification performance.
[0002]
[Prior art]
FIG. 23 is a diagram showing a configuration of a conventional radar apparatus disclosed in, for example, Japanese Patent Laid-Open No. 6-174838. In the figure, 501 is a transmitter, 502 is a transmission / reception switch, 503 is a transmission / reception antenna, 504 is a receiver, 505 is a radar image reproduction means, 506 is a radar image display means, 507 is a target tracking means, and 508 is a point image response estimation. Means 509, target aspect angle estimation means, 510 RCS calculation means, 511 convolution integration means, 512 target shape data storage means, and 513 an operator.
[0003]
FIG. 24 is a diagram showing the positional relationship between the target and the radar and the motion of the target during observation. In the figure, reference numeral 521 denotes a target, and 522 denotes a radar apparatus.
FIG. 25 shows details of the inside of the radar image reproducing means 505 shown in FIG. In the figure, 531 is a range compression means, 532 is a motion compensation means, 533 is a cross range compression means, and 534 is a two-dimensional storage means.
FIG. 26 shows in detail the inside of the radar image display means 506 shown in FIG. In the figure, 541 indicates a two-dimensional display buffer, and 542 indicates a monitor TV.
[0004]
Next, the operation will be described with reference to the drawings. The high frequency signal generated by the transmitter 501 is radiated from the transmission / reception antenna 503 toward the target 521 via the transmission / reception switch 502. A part of the high-frequency signal irradiated to the target 521 is reflected in the direction of the radar device 522, received by the transmission / reception antenna 503, amplified and detected by the receiver 504 via the transmission / reception switch 502, and then by the radar image reproduction means 505. The radar image is converted into a radar image indicating an RCS (Radar Cross Section) distribution of the target 521 and displayed by the radar image display means 506.
[0005]
Hereinafter, a method for reproducing an image will be described in detail.
The received signal output from the receiver 504 is input to the radar image reproduction means 505, and first, the range compression means 531 performs processing for improving the range resolution, that is, pulse compression. The received signal after the range compression is stored in the two-dimensional storage means 534 according to the range bin number m and the pulse hit number n. In order to remove a random component harmful to image reproduction from the movement of the target 521, the received signal is read from the two-dimensional storage unit 534, and the motion compensation unit 532 is set so that the Doppler frequency at the center point of the target 521 becomes zero. Thus, phase compensation and range bin rearrangement are performed, and the result is stored again in the two-dimensional storage means 534.
[0006]
Assuming that the target 521 is rotating or moving straight by yaw motion as shown in FIG. 24, different points on the target existing in the same range bin generate reflected waves having different Doppler frequencies. . Utilizing this, the cross range compression means 533 improves the cross range resolution by performing FFT (Fast Fourier Transform) for each range bin on the received signal after the phase compensation. A radar image that has a high resolution in both the range and cross range directions and represents the RCS distribution of each target point is sent to the radar image display means 506, temporarily stored in the two-dimensional display buffer 541, and then displayed on the monitor TV 542 as an image. Is displayed. A radar apparatus that obtains the shape by utilizing the Doppler effect generated by the target motion is known as ISAR (Inverse Synthetic Aperture Radar).
[0007]
The received signal obtained by the receiver 504 is also supplied to the target tracking unit 507, and the target tracking unit 507 estimates motion characteristics such as the target traveling direction, position, velocity, and acceleration. The point image response estimation means 508 calculates a point image response function corresponding to the impulse response of the radar device from this result and the specifications of the radar device. At the same time, the target aspect angle estimation means 509 estimates the target aspect angle from the positions of the target 521 and the radar device 522 and the traveling direction of the target 521. The target shape data accumulating unit 512 stores three-dimensional shape data for each target. The RCS calculation unit 510 sequentially reads the three-dimensional shape data stored in the target shape data storage unit 512, and calculates the target RCS distribution based on the estimated target aspect angle. For calculating the RCS distribution, for example, well-known methods such as GTD (Geometrical Theory of Diffraction) and PTD (Physical Theory of Diffraction) can be used. At this time, since the resolution of the target shape data does not necessarily match the resolution of the radar apparatus, the convolution integration means 511 performs the convolution integration of the RCS distribution and the point image response function to recognize and identify. Generate a dictionary image for
Since the dictionary image generated in this way is displayed on the radar image display means 506 together with the reproduced radar image, the operator 513 can view it simultaneously, even if the radar image is different from the target image by visible light that is familiar to everyday life. Can be easily recognized and identified.
[0008]
[Problems to be solved by the invention]
The conventional radar apparatus has a problem that the identification performance is low because the target three-dimensional shape cannot be obtained.
Further, the conventional radar apparatus has a problem that the identification performance is low because the target three-dimensional RCS distribution cannot be obtained.
Further, the conventional radar apparatus has a problem that the identification performance is low because the target-specific feature quantity such as the target rotational motion cannot be estimated.
Further, the conventional radar apparatus has a problem that it cannot generate a two-dimensional image having a length of two axes.
[0009]
The present invention has been made to solve the above-described problems, and provides an image radar apparatus that can improve the identification performance and can generate a two-dimensional image having two axes as a length. For the purpose.
[0010]
[Means for Solving the Problems]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device Corresponding point determination circuit for determining the correspondence between each reflection point above, the corresponding point determination result that is the output of the corresponding point determination circuit, the radar image that is the output of each radar image collection device, and the presence direction of the target, respectively A three-dimensional shape restoration circuit that extracts a range of each reflection point in the image and combines the extracted range of each reflection point to restore a target three-dimensional shape.
[0011]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device Corresponding point determination circuit for determining the correspondence between each reflection point above, the determination result of the corresponding point that is the output of the corresponding point determination circuit, and each image in each image obtained from the radar image that is the output of each radar image collection device A reflection intensity three-dimensional distribution construction circuit for constructing a three-dimensional distribution of the reflection intensity on the target from the range of the reflection points and the direction in which the target exists.
[0012]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device Strength-corresponding corresponding point determination circuit for determining correspondence between each reflection point using amplitude value information of each reflection point, corresponding point determination result output from the intensity-considering corresponding point determination circuit, and each radar image A three-dimensional shape restoration circuit that restores the target three-dimensional shape from the range of each reflection point and the target existence direction in each image obtained from the radar image that is the output of the collection device;
[0013]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device An N image corresponding point determination circuit for associating each of the above reflection points for each reflection point using any three of a large number of images, and determination of a corresponding point as an output of the N image corresponding point determination circuit A three-dimensional shape restoration circuit that restores the target three-dimensional shape from the result and the range of each reflection point in each image obtained from the radar image that is the output of each radar image acquisition device and the direction in which the target exists; .
[0014]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device Obtained by a reference point selection circuit that selects a reference point that can be handled among the reflection points above, a reference position estimation circuit that estimates the spatial position of the reference point obtained by the reference point selection circuit, and a reference position estimation circuit The rotational angular velocity vector of the target based on the spatial position of the reference point, the range and Doppler frequency of the image of each reference point obtained by the radar image acquisition device, and the direction of the target based on the position of each radar image acquisition device And a rotational motion estimation circuit having a rotational axis position estimation circuit for estimating the position of the rotational axis.
[0015]
In addition, the apparatus further includes a rotational motion history storage circuit that stores rotational motion estimation results, which are output from the rotational motion estimation circuit, at each time.
[0016]
In addition, a projection plane determination circuit that estimates the scaling of the cross range axis, length, and frequency for each radar image acquisition device based on the estimation result of the rotational motion estimation circuit, and the range and the range based on the estimation result of the projection plane determination circuit It further includes a range / cross range image generation circuit that generates a radar image representing a cross range orthogonal to the range in terms of length with respect to a radar image obtained for each radar image acquisition device.
[0017]
In addition, for each reflection point on each range cross range image generation circuit, the range of each reflection point is limited to a straight line that passes through the reflection point on the range cross range image and is orthogonal to the plane. A straight line intersection determination circuit that determines whether or not the axes appearing in each range image intersect with each other, and the axes related to points on each surface intersect at one point on the entire surface based on the intersection information obtained by the straight line intersection determination circuit An intersection information-considered corresponding point determination circuit that determines a corresponding point based on the information, and a three-dimensional shape construction circuit that constructs a target three-dimensional shape based on information from the intersection information-considered correspondence point determination circuit Is further provided.
[0018]
In addition, for each reflection point on each range cross range image generation circuit, the range of each reflection point is limited to a straight line that passes through the reflection point on the range cross range image and is orthogonal to the plane. A straight line intersection determination circuit that determines whether or not the axes appearing for each range image intersect, an intersection search circuit that determines the three-dimensional coordinates of the intersection point for a set of points determined to intersect, and another range cross For a range image, determine an axis for each reflection point, check if the axis passes through the intersection, and if it passes, correspond to that point and a set of points on each image for the intersection, If not, it further includes an intersection passing type corresponding point determination circuit that determines that it does not correspond, and a three-dimensional shape construction circuit that constructs a target three-dimensional shape based on information of the intersection passing type corresponding point determination circuit. Yes.
[0019]
Further, the target shape data storage means for storing the candidate target shape data, the three-dimensional shape of the observation target restored by the three-dimensional shape restoration circuit, and the candidate target shape data stored in the target shape data storage means are collated. And a three-dimensional shape matching circuit that outputs similar candidate targets.
[0020]
Also, target shape data storage means for storing candidate target shape data, and electromagnetic field theory is applied to the three-dimensional shape data of each candidate target stored in the target shape data to calculate a three-dimensional distribution of the reflection intensity. The RCS calculation means to be similar to the three-dimensional distribution of the reflection intensity of the observation target constructed by the reflection intensity three-dimensional distribution construction circuit and the three-dimensional distribution of the reflection intensity of each candidate target obtained by the RCS calculation means are similar. And a reflection intensity three-dimensional distribution matching circuit for selecting candidate targets.
[0021]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image Radar image collection for obtaining an image radar device that is placed at different positions, transmitting and receiving radio waves to and from the target, collecting the radar image of the target, and estimating the direction of presence of the target based on the radar position Apparatus, a reception-only radar image acquisition apparatus that obtains a target radar image and a range vector related to the radar image using a signal reflected from a target irradiated from a predetermined radar image acquisition apparatus, and a radar image acquisition apparatus or a reception-only radar Corresponding point determination circuit for determining the correspondence between each reflection point on the output image obtained from the image acquisition device, the determination result of the corresponding point that is the output of the corresponding point determination circuit, and each radar image acquisition device or reception-only radar image A three-dimensional shape restoration circuit that restores the target three-dimensional shape from the radar image that is the output of the collection device and the direction in which the target exists.
[0022]
Further, the rotary motion storage means for storing the rotational motion information for each candidate target, the rotational motion history of the observation target for each time stored in the rotary motion history storage circuit, and each candidate target stored in the rotary motion storage means And a rotary motion verification circuit for verifying the rotational motion information for each and outputting candidate targets having similar rotational motion.
[0023]
The radar image acquisition device also transmits and receives a part of the high-frequency pulse reflected and scattered by the target, a transmitter that generates a high-frequency pulse to irradiate the target, a transmission and reception antenna that transmits and receives the high-frequency pulse generated by the transmitter. A receiver that receives and detects via an antenna, a radar image reproducing means that generates a radar image to be observed based on a received signal obtained by the receiver, and a position of the radar image collecting device from the arrival direction of the received signal Range vector calculating means for obtaining the reference target direction as a unit vector.
[0024]
In addition, the radar image collection device receives and detects a part of the high-frequency pulse reflected and scattered by the target via the transmission / reception antenna, and the radar image to be observed based on the received signal obtained by the receiver. Image generating means, and a Bister range vector calculating means for estimating a unit vector in the range direction from the direction of arrival of the received signal and the irradiation direction of the radar image collecting apparatus that has transmitted to obtain the received signal And have.
[0025]
In the radar apparatus according to the present invention, a transmitter that generates a high-frequency pulse to be irradiated to a target, a transmission / reception antenna that transmits and receives the high-frequency pulse generated by the transmitter, a part of the high-frequency pulse reflected and scattered by the target Receiver image that is received and detected via the transmitting / receiving antenna, and the radar image to be observed based on the received signal obtained by the receiver As an ISAR radar image A radar image reproducing means for generating, a range vector calculating means for obtaining the presence direction of the target as a unit vector from the arrival direction of the received signal, and a radar image which is an output of the radar image reproducing means changing every moment according to the relative motion of the radar and the target. A radar image history accumulating unit for accumulating, and a mobile radar image collecting device having a range vector history accumulating unit for accumulating a calculation result of a range vector which is an output of a range vector calculating unit which changes every moment according to the relative motion of the radar and the target; , Corresponding point determination circuit for determining corresponding points from radar images at each time as output of mobile radar image acquisition device, corresponding point determination result of corresponding point determination circuit, and history of range vector as output of mobile radar image acquisition device And a three-dimensional shape restoration circuit for restoring the target three-dimensional shape from the history of the radar image. That.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a processing block diagram showing Embodiment 1 of the image radar apparatus of the present invention. In the figure, 11 is a radar image collection device, 12 is a corresponding point determination circuit, and 13 is a three-dimensional shape restoration circuit.
[0027]
FIG. 2 is a processing block diagram showing in detail the radar image collection device 11 of FIG. In the figure, 501 is a transmitter, 502 is a transmission / reception switch, 503 is a transmission / reception antenna, 504 is a receiver, 505 is a radar image reproduction means, and 14 is a range vector calculation means.
[0028]
FIG. 3 is a geometry for explaining the processing of the present embodiment.
FIG. 4 is an example of an ISAR image obtained by each radar image collection device.
[0029]
Next, the processing content of this Embodiment is demonstrated using FIGS.
First, the processing contents of the radar image collection device 11 will be described. In the radar image collection device 11, the high-frequency signal generated by the transmitter 501 is radiated from the transmission / reception antenna 503 toward the target via the transmission / reception switch 502, and a part of the high-frequency signal irradiated to the target is the radar image collection device 11. The process of reflecting in the direction, receiving this by the transmitting / receiving antenna 503, amplifying / detecting by the receiver 504 via the transmission / reception switch 502, and then converting to a radar image indicating the target RCS by the radar image reproducing means 505 is conventional. It is the same.
[0030]
Further, the range vector calculation means 14 obtains a unit vector in the target direction viewed from the radar image collection device 11 based on the arrival direction of the reflected wave. This unit vector is hereinafter referred to as a range vector.
[0031]
In the present embodiment, as shown in FIG. 3, three radar image collection devices 11 are arranged at different positions. These are called radar # 1, radar # 2, and radar # 3 for convenience. An ISAR image obtained with each radar #n (n = 1, 2, 3) is represented as image #n (n = 1, 2, 3), and a range vector is represented as ssn (n = 1, 2, 3). In each image #n, an observed target image is obtained as shown in FIG. Note that different orientation images are obtained for the same target due to differences in observation direction.
[0032]
The corresponding point determination circuit 12 compares each reflection point on each image, and associates each image. For example, in the example of FIG. 4, it is assumed that the nose, the tip of the wing, the tip of the vertical tail, and the like are associated between the images.
[0033]
Here, the number of reflection points that can be handled is J + 1. One of these points is used as a reference point (the nose P0 in the example of FIG. 4), and the difference in range between this point and each reflection point Pj (j = 1, 2,..., J) in image # n is represented by snj ( n = 1, 2, 3; j = 1, 2,..., j).
[0034]
When the position vector of each reflection point Pj with reference to the point P0 is rrj, the equation (1) is established.
[0035]
[Expression 1]

[0036]
T represents a vector transposition operation.
When this is summarized for each point Pj, the following equation is obtained.
[0037]
[Expression 2]

[0038]
However, ssnx, ssny, and ssnz (n = 1, 2, 3) represent the first element, the second element, and the third element of the vector ssn. When the equation (2) is transformed, the following equation is obtained.
[0039]
[Equation 3]

[0040]
The three-dimensional shape restoration circuit 13 calculates a three-dimensional position vector of the point Pj based on the equation (3), and arranges the point at that position.
By performing the same process for each point, the three-dimensional shape of the observation target can be obtained as a point distribution.
[0041]
In the image radar apparatus having such a configuration, since the target three-dimensional shape can be known, the identification performance is improved.
[0042]
Embodiment 2. FIG.
FIG. 5 is a processing block diagram showing Embodiment 2 of the image radar apparatus of the present invention. In the figure, 21 is a reflection intensity three-dimensional distribution construction circuit.
[0043]
Next, the processing content of this Embodiment is demonstrated using FIG.
In the present embodiment, the reflection intensity is given to the position of each reflection point, which is the output of the three-dimensional shape restoration circuit 13 in the first embodiment, from the ISAR image obtained by each radar image collection device 11.
[0044]
That is, in the reflection intensity three-dimensional distribution construction circuit 21, for each ISAR image image # 1, image # 2, image # 3 obtained by each radar image collection device 11, each obtained by the three-dimensional shape restoration circuit 13 is obtained. The reflection intensity of the reflection point Pj is assigned to the three-dimensional coordinates of the reflection point. The three-dimensional reflection intensity distribution obtained in this way corresponds to the reflection intensity distribution on the target when the target is observed from the direction of each radar image collection device 11.
[0045]
In the image radar apparatus having such a configuration, since the target three-dimensional shape can be known, the identification performance is improved.
In addition, since the target three-dimensional reflection intensity distribution can be known, the identification performance is improved.
[0046]
Embodiment 3 FIG.
FIG. 6 is a processing block diagram showing Embodiment 3 of the image radar apparatus of the present invention. In the figure, 31 is a strength consideration corresponding point determination circuit.
[0047]
Next, the processing content of this Embodiment is demonstrated using FIG.
In the present embodiment, the reflection points between the image #n are associated with each other using the reflection intensity distribution obtained by the radar image collection device 11.
[0048]
The intensity-considered corresponding point determination circuit 31 associates reflection points based on information on the intensity of reflection points in each image. For example, when the target directions viewed from the radar image acquisition device 11 are similar, the reflection intensity at the same reflection point takes a close value.
[0049]
In the image radar apparatus having such a configuration, since the target three-dimensional shape can be known, the identification performance is improved.
In addition, since the target three-dimensional reflection intensity distribution can be known, the identification performance is improved.
Furthermore, since the three-dimensional shape is constructed using the reflection intensity, the construction accuracy of the three-dimensional shape is improved.
[0050]
Embodiment 4 FIG.
FIG. 7 is a processing block diagram showing Embodiment 4 of the image radar apparatus of the present invention. In the figure, reference numeral 41 denotes an N image corresponding point determination circuit. FIG. 8 is a diagram for explaining the processing of the present embodiment.
[0051]
Next, processing contents of the present embodiment will be described with reference to FIGS.
In the first embodiment, the three-dimensional shape of the observation target is restored using the ISAR images image # 1, image # 2, and image # 3 obtained by the three radar image collection devices 11 arranged at different positions.
[0052]
However, when this is done, it is necessary for the reflection point to correspond to the three images. However, depending on the position of the reflection point, reflection characteristics, etc., there is a possibility that it will not be detected in any image. Therefore, three or more N radar image collection devices 11 are prepared to obtain ISAR images image # 1 to image # N.
[0053]
The N image corresponding point determination circuit 41 selects, for each reflection point, three images from which these reflection points can be confirmed for each reflection point. On the other hand, the three-dimensional shape restoration circuit 13 obtains a three-dimensional position vector by applying Expression (3) as in the first embodiment.
[0054]
In the image radar apparatus having such a configuration, since the target three-dimensional shape can be known, the identification performance is improved.
In addition, since a three-dimensional shape is constructed using a large number of images, for example, when three images cannot be seen with an image having a reflection point, the range vectors of the three radar image collection devices are not linearly independent. It is possible to deal with cases where there is no such thing.
[0055]
Embodiment 5 FIG.
FIG. 9 is a processing block diagram showing Embodiment 5 of the image radar apparatus of the present invention. In the figure, 51 is a reference point selection circuit, 52 is a reference position estimation circuit, 53 is a rotation angular velocity vector estimation circuit, 54 is a rotation axis position estimation circuit, and 55 is a rotation motion estimation circuit. FIG. 10 is a diagram for explaining the processing contents of the present embodiment.
[0056]
Next, processing contents of the present embodiment will be described with reference to FIGS.
Radar images image # 1, image # 2, and image # 3 are obtained by the three radar image collection devices 11.
The reference point selection circuit 51 selects four points P0 to P3 on the target.
[0057]
The reference position estimation circuit 52 obtains a distance snm (n = 1, 2, 3; m = 1, 2, 3) of each reflection point Pm with reference to the reflection point P0 on each image # n. Furthermore, using the range vector ssn of each radar image collection device 11, a three-dimensional position vector based on P0 is obtained by Equation (3).
[0058]
The rotation angular velocity vector estimation circuit 53 obtains the Doppler frequency fnm of each reflection point Pm with reference to P0 in image # n, and obtains the relative velocity vnm of each reflection point Pm with reference to P0 by the following equation.
[0059]
[Expression 4]

[0060]
Where λ is the transmission wavelength. The relationship between vnm, ssn, rrm, and rotational angular velocity vector LL is as follows.
[0061]
[Equation 5]

[0062]
However, when AA and BB are vectors, (AA · BB) represents an inner product operation of AA and BB, and (AA × BB) represents an outer product operation of AA and BB.
Here, there are nine types of vectors rrm × ssn when n and m are changed. From these, three types of primary independent vectors are selected, which are set as ggk (k = 1, 2, 3), and the relative velocity corresponding to the vector is set as vk, the following equation is established.
[0063]
[Formula 6]

[0064]
However, ggkx, ggky, ggkz (k = 1, 2, 3) are the first, second and third elements of the vector ggk. Therefore, LL is given by the following equation.
[0065]
[Expression 7]

[0066]
That is, an angular velocity vector representing the target rotational motion is determined.
[0067]
In the image radar apparatus having such a configuration, an angular velocity vector representing a target rotational motion can be obtained, and thus identification using this value can be performed.
[0068]
In the present embodiment, the number of radar image collection devices is three. Needless to say, the number of radar image collection devices is three or more.
[0069]
Embodiment 6 FIG.
FIG. 11 is a processing block diagram showing Embodiment 6 of the image radar apparatus of the present invention. In the figure, reference numeral 61 denotes a rotational movement history accumulation circuit.
[0070]
Next, the processing content of this Embodiment is demonstrated using FIG.
The process of estimating the rotational angular velocity vector LL by the rotational motion estimation circuit 55 using the three ISAR images obtained by the radar image acquisition device 11 is the same as that of the fifth embodiment. In the present embodiment, this rotational angular velocity vector is stored in the rotational motion history storage circuit 61.
[0071]
In the image radar apparatus having such a configuration, the temporal change of the angular velocity vector representing the target rotational motion can be obtained, so that motion information such as the pitch motion cycle can be obtained.
[0072]
Embodiment 7 FIG.
FIG. 12 is a processing block diagram showing Embodiment 7 of the image radar apparatus of the present invention. In the figure, 71 is a projection plane determination circuit, and 72 is a range / cross-range image generation circuit.
[0073]
Next, processing contents of the present embodiment will be described with reference to FIG.
In the present embodiment, using the angular velocity vector LL obtained by the rotational motion estimation circuit 55 of the fifth embodiment, the projection plane determination circuit 71 first determines the projection plane of the target shape for each radar image collection device 11. . Assuming that the position vector with reference to P0 of the reflection point Pm on the target is rrm, the range with reference to P0 on the ISAR image, and the Doppler frequencies are snm and fnm, the following equations are given between these variables: To establish.
[0074]
[Equation 8]

[0075]
[Equation 9]

[0076]
Here, a vector ccn that satisfies the following equation is introduced.
[0077]
[Expression 10]

[0078]
This ccn is a unit vector in the same direction as the vector ssn × LL, and is hereinafter referred to as a cross range vector.
From Expressions (8) and (10), the plane defined by ssn and ccn in the space is the projection plane for projecting the target shape. The following equation is established from the relationship of equations (9) and (10).
[0079]
[Expression 11]

[0080]
Here, since the right side is the inner product of the position vector rrm and ccn of the reflection point Pm, the left side represents the projection component of rrm in the ccn direction. Based on this, the range / cross-range image generation circuit 72 multiplies the collected ISAR image image # n (n = 1, 2, 3) by −λ / (2 || ssn × LL ||) times in the frequency direction. To do.
[0081]
As a result, a range cross-range image having distance axes in both the ssn and ccn directions is obtained. The length in the cross range direction at this time is cnm.
[0082]
In the image radar apparatus having such a configuration, a target image can be obtained with respect to the target for each radar image collecting apparatus and the length in the cross range direction orthogonal to the range. Identification performance can be improved.
[0083]
Embodiment 8 FIG.
FIG. 13 is a processing block diagram showing Embodiment 8 of the image radar apparatus of the present invention. In the figure, 81 is a straight line intersection determination circuit, and 82 is an intersection information consideration type corresponding point determination circuit.
[0084]
Next, processing contents of the present embodiment will be described with reference to FIG.
In the present embodiment, the range vector ssn (n = 1, 2, 3) for determining the projection plane for each radar image acquisition device 11 and the cross range vector ccn ( n = 1, 2, 3) and the coordinates snp, cnp of the reflection points on each image # n are used to associate the reflection points on the three images, and then a three-dimensional shape is constructed.
[0085]
In the straight line intersection determination circuit 81, first, a normal vector ttn of the projection plane for each radar image collection device 11 is obtained by the following equation.
[0086]
[Expression 12]

[0087]
If the position vector when the reflection point P is projected on each projection plane n is uupn, upn is given by the following equation.
[0088]
[Formula 13]

[0089]
The reflection point P passes through upn and exists on the axis in the ttn direction.
Now, when the same points are observed on the surfaces na and nb, the above axes intersect at a certain point. Therefore, it is determined whether or not the above-mentioned axes intersect, and if they intersect, it is determined as a combination candidate of the same reflection point. The following formula is used to determine whether the axes intersect.
[0090]
[Expression 14]

[0091]
When a in the above equation is 0, the two axes intersect. Otherwise, the two shafts are in a twisted position.
[0092]
The straight line intersection determination circuit 81 determines intersection between axes passing through reflection points on each surface based on the above information.
[0093]
Based on the information from the straight line intersection determination circuit 81, the intersection information consideration type corresponding point determination circuit 82 determines a combination of points on each surface through which the same axis passes the same point.
The three-dimensional shape restoration circuit 13 restores the three-dimensional shape by the same method as in the first embodiment based on the combination information obtained by the intersection information consideration type corresponding point determination circuit 82.
[0094]
In the image radar apparatus having such a configuration, the three-dimensional shape is constructed using the axis intersection information regarding the target, so that the accuracy of the three-dimensional shape construction is improved and the identification performance is improved.
[0095]
Embodiment 9 FIG.
FIG. 14 is a processing block diagram showing Embodiment 9 of the image radar apparatus of the present invention. In the figure, 91 is an intersection search circuit, and 92 is an intersection passing type corresponding point determination circuit.
[0096]
Next, the processing content of this Embodiment is demonstrated using FIG.
In the same process as in the eighth embodiment, it is determined whether or not the reflection points on the images of image #na and image #nb of image # 1 to image # 3 intersect.
[0097]
If the position vectors on the image of the reflection points on image # na and image # nb determined to intersect are rrnap and rrnbp, the position vector rrr of the intersection is given by the following equation.
[0098]
[Expression 15]

[0099]
Here, α and β are unknowns. Now, ttna and ttnb are both three-dimensional vectors, but a two-dimensional vector can be generated by appropriately selecting two of these elements (for example, the first element and the second element). Two-dimensional vectors are generated by selecting the same two elements at ttna and ttnb. This is defined as (txa, tya), (txb, tyb). However, primary independent sets are selected as these two-dimensional vectors. In addition, the two-dimensional vectors generated from rrnap and rrnbp with respect to the same element are assumed to be (rxa, rya) and (rxb, ryb), respectively. Note that these two-dimensional vectors are all considered column vectors.
α and β are determined by the following equations.
[0100]
[Expression 16]

[0101]
Therefore, rrr in equation (15) is determined.
The intersection search circuit 91 performs the above processing.
[0102]
When the point rrncp corresponding to the reflection point of the position vector rrr exists on the remaining one image # nc of image # 1 to image # 3, the following equation is established.
[0103]
[Expression 17]

[0104]
Here, γ is an appropriate constant. Therefore, when Equation (17) is applied to each intersection obtained between each reflection point on image # na and image # nb and each reflection point on image # nc, and there is a set satisfying this, Thus, it can be determined that the reflection point on each image related to the intersection point is associated with the reflection point on image # nc.
[0105]
The intersection passing type corresponding point determination circuit 92 determines the correspondence between the reflection points based on the above-described properties. The three-dimensional shape restoration circuit 13 restores the three-dimensional shape based on this result.
[0106]
In the image radar apparatus having such a configuration, since the three-dimensional shape is constructed using the axis intersection information, the accuracy of the three-dimensional shape construction is improved and the identification performance is improved.
[0107]
Embodiment 10 FIG.
FIG. 15 is a processing block diagram showing Embodiment 10 of the image radar apparatus of the present invention. In the figure, reference numeral 101 denotes a three-dimensional shape matching circuit.
[0108]
Next, processing contents of the present embodiment will be described with reference to FIG.
The process of constructing the three-dimensional shape of the observation target by the process up to the three-dimensional shape restoration circuit 13 is the same as that of the first embodiment. In the three-dimensional shape matching circuit 101, the three-dimensional shape of each candidate target stored in the target shape data storage unit 512 and the three-dimensional shape of the observation target constructed by the three-dimensional shape restoration circuit 13 are checked. The candidate target determined to be the best match as a result of collation is output as the observation target identification result.
[0109]
In the image radar apparatus having such a configuration, since the type of observation target can be identified using a three-dimensional shape, the identification performance is improved.
[0110]
Embodiment 11 FIG.
FIG. 16 is a processing block diagram showing Embodiment 11 of the image radar apparatus of the present invention. In the figure, reference numeral 111 denotes a reflection intensity three-dimensional distribution matching circuit.
[0111]
Next, the processing content of this Embodiment is demonstrated using FIG.
The process of obtaining the three-dimensional distribution of reflection intensity of the observation target by the process up to the reflection intensity three-dimensional distribution construction circuit 21 is the same as in the second embodiment.
In the reflection intensity three-dimensional distribution matching circuit 111, the candidate target obtained by applying the RCS calculation means 510 to the three-dimensional shape of each candidate target accumulated in the reflection intensity three-dimensional distribution of the observation target and the target shape data accumulation means 512. The three-dimensional distribution of the reflection intensity is collated to identify the type.
[0112]
In the image radar apparatus having such a configuration, the type of observation target can be identified using a three-dimensional reflection intensity distribution, so that the identification performance is improved.
[0113]
Embodiment 12 FIG.
FIG. 17 is a processing block diagram showing Embodiment 12 of the image radar apparatus of the present invention. In the figure, reference numeral 121 denotes a reception-only image collection device. FIG. 18 is a processing block diagram showing in detail the reception-only image collection device 121 of FIG. In the figure, 122 is a Bister range vector calculation means.
[0114]
Next, processing contents of the present embodiment will be described with reference to FIGS. 17 and 18.
In the present embodiment, a target three-dimensional shape is constructed using radar images obtained by one radar image collection device 11 and two reception-only radar image collection devices 121. In the reception-only radar image collection device 121, the radio wave irradiated from the radar image collection device 11 and scattered by the target is received by the receiver 504 via the reception antenna 503, and the radar image reproduction means 505 reproduces the radar image. .
[0115]
The bistar range vector calculation means 122 calculates a range vector in the bistatic configuration from the arrival direction of the reflected wave and the irradiation direction from the radar image collection device 11 to the target.
Hereinafter, the processing in the corresponding point determination circuit 12 and the three-dimensional shape restoration circuit 13 is the same as that in the first embodiment.
[0116]
In the present embodiment, the same effect as in the first embodiment can be realized with a simpler configuration.
[0117]
Embodiment 13 FIG.
FIG. 19 is a processing block diagram showing Embodiment 13 of the image radar apparatus of the present invention. In the figure, 131 is a rotational motion accumulating means, and 132 is a rotational motion collating circuit.
[0118]
Next, the processing content of this Embodiment is demonstrated using FIG.
In the present embodiment, the target rotational motion history accumulated in the rotational motion history accumulation circuit 61 by the same processing as in the sixth embodiment is used as the candidate target rotational motion history (preliminarily accumulated in the rotational motion accumulation means 131 ( For example, a candidate target whose rotational motion is similar to that of a yaw, roll, pitch motion or the like is determined as a target identification result.
[0119]
In the image radar apparatus having such a configuration, identification performance is improved because identification is performed using motion information unique to each target.
[0120]
Embodiment 14 FIG.
FIG. 20 is a processing block diagram showing Embodiment 14 of the image radar apparatus of the present invention. In the figure, 131 is a mobile radar image collection device. FIG. 21 is a processing block diagram showing in detail the mobile radar image collection device 131 of FIG. In the figure, 132 is a radar image history storage means, and 133 is a range vector history storage means. FIG. 22 is a diagram for explaining the processing contents of the present embodiment.
[0121]
Next, processing contents of the present embodiment will be described with reference to FIGS. 20, 21, and 22.
In the present embodiment, it is assumed that the mobile radar image collection device observes a target while moving the place as time advances as t = t1, t2, t3.
[0122]
In the mobile radar image collection device 131, the processing up to the radar image reproduction means 505 and the range vector calculation means 14 is the same as that of the radar image collection device 11 shown in the first embodiment. In the mobile radar image collection device 131, a radar image history accumulating unit 132 is disposed after the radar image reproducing unit, and the radar image radar # n at each time tn is accumulated. Further, a range vector history accumulating unit 133 is arranged at the subsequent stage of the range vector calculating unit 14, and the range vector ssn at each time tn is accumulated. Thereafter, the corresponding point determination circuit 12 determines the correspondence between the images, and the three-dimensional shape restoration circuit 13 restores the three-dimensional shape in the same manner as in the first embodiment.
[0123]
In other words, this embodiment has an advantage that the same effect as that of the first embodiment can be obtained with a small number of radar image collection devices.
[0124]
【The invention's effect】
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device Corresponding point determination circuit for determining the correspondence between each reflection point above, the corresponding point determination result that is the output of the corresponding point determination circuit, the radar image that is the output of each radar image collection device, and the presence direction of the target, respectively A three-dimensional shape restoration circuit that extracts a range of each reflection point in the image and combines the extracted range of each reflection point to restore a target three-dimensional shape. Therefore, the target three-dimensional shape can be known, and the identification performance can be improved.
[0125]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device Corresponding point determination circuit for determining the correspondence between each reflection point above, the determination result of the corresponding point that is the output of the corresponding point determination circuit, and each image in each image obtained from the radar image that is the output of each radar image collection device A reflection intensity three-dimensional distribution construction circuit for constructing a three-dimensional distribution of the reflection intensity on the target from the range of the reflection points and the direction in which the target exists. For this reason, the target three-dimensional shape can be known, the identification performance can be improved, and the target three-dimensional reflection intensity distribution can be known, so that the identification performance is further improved.
[0126]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device Strength-corresponding corresponding point determination circuit for determining correspondence between each reflection point using amplitude value information of each reflection point, corresponding point determination result output from the intensity-considering corresponding point determination circuit, and each radar image A three-dimensional shape restoration circuit that restores the target three-dimensional shape from the range of each reflection point and the target existence direction in each image obtained from the radar image that is the output of the collection device; Therefore, the target three-dimensional shape can be known, the identification performance can be improved, and the target three-dimensional reflection intensity distribution can be known, so that the identification performance is improved. Furthermore, since the three-dimensional shape is constructed using the reflection intensity, the construction accuracy of the three-dimensional shape is improved.
[0127]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device An N image corresponding point determination circuit for associating each of the above reflection points for each reflection point using any three of a large number of images, and determination of a corresponding point as an output of the N image corresponding point determination circuit A three-dimensional shape restoration circuit that restores the target three-dimensional shape from the result and the range of each reflection point in each image obtained from the radar image that is the output of each radar image acquisition device and the direction in which the target exists; . Therefore, since the target three-dimensional shape can be known, the identification performance is improved, and a three-dimensional shape is constructed using a large number of images. When it is not visible, the three radar image acquisition devices can cope with the case where the range vectors are not linearly independent.
[0128]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image A plurality of radar image acquisition devices for acquiring target radar images arranged at different positions and estimating a target presence direction based on the radar position, and an output image of each radar image acquisition device Obtained by a reference point selection circuit that selects a reference point that can be handled among the reflection points above, a reference position estimation circuit that estimates the spatial position of the reference point obtained by the reference point selection circuit, and a reference position estimation circuit The rotational angular velocity vector of the target based on the spatial position of the reference point, the range and Doppler frequency of the image of each reference point obtained by the radar image acquisition device, and the direction of the target based on the position of each radar image acquisition device And a rotational motion estimation circuit having a rotational axis position estimation circuit for estimating the position of the rotational axis. Therefore, since an angular velocity vector representing the target rotational motion can be obtained, discrimination using this value can be performed, and the discrimination performance is further improved.
[0129]
In addition, the apparatus further includes a rotational motion history storage circuit that stores rotational motion estimation results, which are output from the rotational motion estimation circuit, at each time. Thereby, since the time change of the angular velocity vector showing the target rotational motion can be obtained, motion information such as the pitch motion cycle can be obtained.
[0130]
In addition, a projection plane determination circuit that estimates the scaling of the cross range axis, length, and frequency for each radar image acquisition device based on the estimation result of the rotational motion estimation circuit, and the range and the range based on the estimation result of the projection plane determination circuit It further includes a range / cross range image generation circuit that generates a radar image representing a cross range orthogonal to the range in terms of length with respect to a radar image obtained for each radar image acquisition device. Therefore, a target image can be obtained with respect to the target for each radar image acquisition device and the length in the cross range direction orthogonal thereto as an axis, and this can be used to improve target identification performance.
[0131]
In addition, for each reflection point on each range cross range image generation circuit, the range of each reflection point is limited to a straight line that passes through the reflection point on the range cross range image and is orthogonal to the plane. A straight line intersection determination circuit that determines whether or not the axes appearing in each range image intersect with each other, and the axes related to points on each surface intersect at one point on the entire surface based on the intersection information obtained by the straight line intersection determination circuit An intersection information-considered corresponding point determination circuit that determines a corresponding point based on the information, and a three-dimensional shape construction circuit that constructs a target three-dimensional shape based on information from the intersection information-considered correspondence point determination circuit Is further provided. Therefore, regarding the target, since the three-dimensional shape is constructed using the axis intersection information, the accuracy of the three-dimensional shape construction is improved and the identification performance is improved.
[0132]
In addition, for each reflection point on each range cross range image generation circuit, the range of each reflection point is limited to a straight line that passes through the reflection point on the range cross range image and is orthogonal to the plane. A straight line intersection determination circuit that determines whether or not the axes appearing for each range image intersect, an intersection search circuit that determines the three-dimensional coordinates of the intersection point for a set of points determined to intersect, and another range cross For a range image, determine an axis for each reflection point, check if the axis passes through the intersection, and if it passes, correspond to that point and a set of points on each image for the intersection, If not, it further includes an intersection passing type corresponding point determination circuit that determines that it does not correspond, and a three-dimensional shape construction circuit that constructs a target three-dimensional shape based on information of the intersection passing type corresponding point determination circuit. Yes. Therefore, regarding the target, since the three-dimensional shape is constructed using the axis intersection information, the accuracy of the three-dimensional shape construction is improved and the identification performance is improved.
[0133]
Further, the target shape data storage means for storing the candidate target shape data, the three-dimensional shape of the observation target restored by the three-dimensional shape restoration circuit, and the candidate target shape data stored in the target shape data storage means are collated. And a three-dimensional shape matching circuit that outputs similar candidate targets. Therefore, the type of observation target can be identified using the three-dimensional shape, and the identification performance is improved.
[0134]
Also, target shape data storage means for storing candidate target shape data, and electromagnetic field theory is applied to the three-dimensional shape data of each candidate target stored in the target shape data to calculate a three-dimensional distribution of the reflection intensity. The RCS calculation means to be similar to the three-dimensional distribution of the reflection intensity of the observation target constructed by the reflection intensity three-dimensional distribution construction circuit and the three-dimensional distribution of the reflection intensity of each candidate target obtained by the RCS calculation means are similar. And a reflection intensity three-dimensional distribution matching circuit for selecting candidate targets. Therefore, the type of observation target can be identified using the three-dimensional reflection intensity distribution, and the identification performance is improved.
[0135]
In the radar apparatus according to the present invention, the target is irradiated with radio waves, and the shape information of the target is obtained using the reflected wave from the target. As an ISAR radar image Radar image collection for obtaining an image radar device that is placed at different positions, transmitting and receiving radio waves to and from the target, collecting the radar image of the target, and estimating the direction of presence of the target based on the radar position Apparatus, a reception-only radar image acquisition apparatus that obtains a target radar image and a range vector related to the radar image using a signal reflected from a target irradiated from a predetermined radar image acquisition apparatus, and a radar image acquisition apparatus or a reception-only radar Corresponding point determination circuit for determining the correspondence between each reflection point on the output image obtained from the image acquisition device, the determination result of the corresponding point that is the output of the corresponding point determination circuit, and each radar image acquisition device or reception-only radar image A three-dimensional shape restoration circuit that restores the target three-dimensional shape from the radar image that is the output of the collection device and the direction in which the target exists. Therefore, the radar apparatus can be realized with a simpler configuration, and the cost can be reduced.
[0136]
Further, the rotary motion storage means for storing the rotational motion information for each candidate target, the rotational motion history of the observation target for each time stored in the rotary motion history storage circuit, and each candidate target stored in the rotary motion storage means And a rotary motion verification circuit for verifying the rotational motion information for each and outputting candidate targets having similar rotational motion. In such a configuration, the identification performance is improved because the identification is performed using the unique motion information for each target.
[0137]
The radar image acquisition device also transmits and receives a part of the high-frequency pulse reflected and scattered by the target, a transmitter that generates a high-frequency pulse to irradiate the target, a transmission and reception antenna that transmits and receives the high-frequency pulse generated by the transmitter. A receiver that receives and detects via an antenna, a radar image reproducing means that generates a radar image to be observed based on a received signal obtained by the receiver, and a position of the radar image collecting device from the arrival direction of the received signal Range vector calculating means for obtaining the reference target direction as a unit vector. Therefore, a unit vector in the target direction viewed from the radar image acquisition device, that is, a range vector, can be obtained based on the arrival direction of the reflected wave.
[0138]
In addition, the radar image collection device receives and detects a part of the high-frequency pulse reflected and scattered by the target via the transmission / reception antenna, and the radar image to be observed based on the received signal obtained by the receiver. Image generating means, and a Bister range vector calculating means for estimating a unit vector in the range direction from the direction of arrival of the received signal and the irradiation direction of the radar image collecting apparatus that has transmitted to obtain the received signal And have. Therefore, the range vector in the bistatic configuration can be calculated based on the arrival direction of the reflected wave and the irradiation direction from the radar image acquisition device to the target.
[0139]
In the radar apparatus according to the present invention, a transmitter that generates a high-frequency pulse to be irradiated to a target, a transmission / reception antenna that transmits and receives the high-frequency pulse generated by the transmitter, a part of the high-frequency pulse reflected and scattered by the target Receiver image that is received and detected via the transmitting / receiving antenna, and the radar image to be observed based on the received signal obtained by the receiver As an ISAR radar image A radar image reproducing means for generating, a range vector calculating means for obtaining the presence direction of the target as a unit vector from the arrival direction of the received signal, and a radar image which is an output of the radar image reproducing means changing every moment according to the relative motion of the radar and the target. A radar image history accumulating unit for accumulating, and a mobile radar image collecting device having a range vector history accumulating unit for accumulating a calculation result of a range vector which is an output of a range vector calculating unit which changes every moment according to the relative motion of the radar and the target; , Corresponding point determination circuit for determining corresponding points from radar images at each time as output of mobile radar image acquisition device, corresponding point determination result of corresponding point determination circuit, and history of range vector as output of mobile radar image acquisition device And a three-dimensional shape restoration circuit for restoring the target three-dimensional shape from the history of the radar image. That. Therefore, there is an advantage that the same effect can be obtained with a small number of radar image collection devices.
[Brief description of the drawings]
FIG. 1 is a processing block diagram showing a first embodiment of an image radar apparatus of the present invention.
FIG. 2 is a processing block diagram showing in detail the radar image collection apparatus of FIG. 1;
FIG. 3 is a geometry for explaining the processing of the first embodiment.
FIG. 4 is an example of an ISAR image obtained by each radar image collection device.
FIG. 5 is a processing block diagram showing a second embodiment of the image radar apparatus of the present invention.
FIG. 6 is a processing block diagram showing a third embodiment of the image radar apparatus of the present invention.
FIG. 7 is a processing block diagram showing Embodiment 4 of the image radar apparatus of the present invention.
FIG. 8 is a diagram for explaining processing of the fourth embodiment.
FIG. 9 is a processing block diagram showing Embodiment 5 of an image radar apparatus of the present invention.
FIG. 10 is a diagram for explaining the processing contents of a fifth embodiment.
FIG. 11 is a processing block diagram showing Embodiment 6 of an image radar apparatus of the present invention.
FIG. 12 is a processing block diagram showing Embodiment 7 of the image radar apparatus of the present invention.
FIG. 13 is a processing block diagram showing an eighth embodiment of the image radar apparatus of the present invention.
FIG. 14 is a processing block diagram showing Embodiment 9 of an image radar apparatus of the present invention.
FIG. 15 is a processing block diagram showing Embodiment 10 of an image radar apparatus of the present invention.
FIG. 16 is a processing block diagram showing an eleventh embodiment of the image radar apparatus of the present invention.
FIG. 17 is a processing block diagram showing Embodiment 12 of an image radar apparatus of the present invention.
FIG. 18 is a processing block diagram showing in detail the reception-only image collection device of FIG. 17;
FIG. 19 is a processing block diagram showing Embodiment 13 of an image radar apparatus of the present invention.
FIG. 20 is a processing block diagram showing Embodiment 14 of an image radar apparatus of the present invention.
FIG. 21 is a processing block diagram showing in detail the mobile radar image collection device of FIG. 20;
FIG. 22 is a diagram for explaining the processing content of the fourteenth embodiment;
FIG. 23 is a diagram showing a configuration of a conventional radar apparatus.
FIG. 24 is a diagram showing the positional relationship between the target and the radar and the motion of the target during observation.
25 shows in detail the inside of the radar image reproducing means shown in FIG.
26 shows in detail the inside of the radar image display means shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Radar image collection device, 12 Corresponding point determination circuit, 13 Three-dimensional shape restoration circuit, 21 Reflection intensity three-dimensional distribution construction circuit, 31 Intensity consideration corresponding point determination circuit, 41N image corresponding point determination circuit, 51 Reference point selection circuit, 52 Reference position estimation circuit, 53 Rotational angular velocity vector estimation circuit, 54 Rotational axis position estimation circuit, 55 Rotation motion estimation circuit, 61 Rotation motion history accumulation circuit, 71 Projection plane determination circuit, 72 Range / cross range image generation circuit, 81 Straight line intersection Determination circuit, 82 intersection information-considered corresponding point determination circuit, 91 intersection search circuit, 92 intersection passing type corresponding point determination circuit, 512 target shape data storage means, 101 three-dimensional shape matching circuit, 510 RCS calculation means, 111 reflection intensity 3 Dimensional distribution verification circuit, 121 Receive-only radar image acquisition device, 131 Rotation motion storage means, 132 Rotation motion verification Road, 501 transmitter, 503 transmit and receive antenna, 504 a receiver, 505 radar image reproducing means 14 range vector calculating means, 122 by static range vector calculating means, 132 radar image history storage means 131 moves the radar image acquisition device

Claims (16)

An image radar apparatus that irradiates a target with radio waves and uses a reflected wave from the target to obtain target shape information as an ISAR radar image ,
A plurality of radar image collection devices that are arranged at different positions and collect target radar images and estimate the direction of presence of the target based on the radar position;
A corresponding point determination circuit for determining a correspondence between each reflection point on the output image of each radar image collection device;
The range of each reflection point in each image is extracted from the determination result of the corresponding point that is the output of the corresponding point determination circuit, the radar image that is the output of each radar image collection device, and the direction of the target, and each of the extracted points A radar apparatus comprising: a three-dimensional shape restoration circuit that restores a target three-dimensional shape by combining ranges of reflection points. An image radar apparatus that irradiates a target with radio waves and uses a reflected wave from the target to obtain target shape information as an ISAR radar image ,
A plurality of radar image collection devices that are arranged at different positions and collect target radar images and estimate the direction of presence of the target based on the radar position;
A corresponding point determination circuit for determining a correspondence between each reflection point on the output image of each radar image collection device;
Reflection intensity on the target from the corresponding point determination result output from the corresponding point determination circuit and the range of each reflection point and target presence direction in each image obtained from the radar image output from each radar image acquisition device A radar apparatus comprising: a reflection intensity three-dimensional distribution construction circuit for constructing a three-dimensional distribution related to An image radar apparatus that irradiates a target with radio waves and uses a reflected wave from the target to obtain target shape information as an ISAR radar image ,
A plurality of radar image collection devices that are arranged at different positions and collect target radar images and estimate the direction of presence of the target based on the radar position;
An intensity-considered corresponding point determination circuit that determines the correspondence between each reflection point on the output image of each radar image collection device using the amplitude value information of each reflection point;
Based on the corresponding point determination result that is the output of the intensity-considered corresponding point determination circuit and the range of each reflection point and the target presence direction in each image obtained from the radar image that is the output of each radar image acquisition device, A radar apparatus comprising: a three-dimensional shape restoration circuit for restoring a three-dimensional shape. An image radar apparatus that irradiates a target with radio waves and uses a reflected wave from the target to obtain target shape information as an ISAR radar image ,
A plurality of radar image collection devices that are arranged at different positions and collect target radar images and estimate the direction of presence of the target based on the radar position;
An N image corresponding point determination circuit for associating each reflection point on the output image of each radar image collection device with each reflection point using any three of a large number of images;
The target 3 is determined based on the corresponding point determination result output from the N image corresponding point determination circuit, the range of each reflection point in each image obtained from the radar image output from each radar image collection device, and the target presence direction. A radar apparatus comprising: a three-dimensional shape restoration circuit for restoring a three-dimensional shape. An image radar apparatus that irradiates a target with radio waves and uses a reflected wave from the target to obtain target shape information as an ISAR radar image ,
A plurality of radar image collection devices that are arranged at different positions and collect target radar images and estimate the direction of presence of the target based on the radar position;
A reference point selection circuit for selecting a reference point that can be matched among the reflection points on the output image of each radar image acquisition device, and a reference position for estimating the spatial position of the reference point obtained by the reference point selection circuit The estimation circuit, the spatial position of the reference point obtained by the reference position estimation circuit, the range and Doppler frequency on the image of the image of each reference point obtained by the radar image collection device, and the position of each radar image collection device A rotational angular velocity vector estimation circuit that estimates a target rotational angular velocity vector from a reference target direction, and a rotational motion estimation circuit that has a rotational axis position estimation circuit that estimates a rotational axis position. Radar device. The radar apparatus according to claim 5, further comprising a rotational motion history accumulation circuit that accumulates a rotational motion estimation result that is an output of the rotational motion estimation circuit at each time. A projection plane determination circuit that estimates the cross-range axis, length, and frequency scaling for each radar image acquisition device based on the estimation result of the rotational motion estimation circuit;
Range / cross-range image generation based on the estimation result of the projection plane determination circuit, which generates a radar image that represents the range and the cross range orthogonal to the range in terms of the radar image obtained for each radar image acquisition device The radar apparatus according to claim 5, further comprising a circuit. For each reflection point on each range cross range image generation circuit, the range of each reflection point is limited to a straight line that passes through the reflection point on the range cross range image and is orthogonal to the plane. A straight line intersection determination circuit for determining whether or not the axes appearing for each image intersect;
Based on the intersection information obtained by the above-described straight intersection determination circuit, the intersection information-considered corresponding point determination is performed by searching for points where the axes related to the points on each surface intersect at one point on the entire surface, and determining corresponding points based on this. Circuit,
The radar apparatus according to claim 7, further comprising a three-dimensional shape construction circuit that constructs a target three-dimensional shape based on information of the intersection information consideration type corresponding point determination circuit. For each reflection point on each range cross range image generation circuit, the range of each reflection point is limited to a straight line that passes through the reflection point on the range cross range image and is orthogonal to the plane. A straight intersection determination circuit that determines whether or not the axes appearing for each image intersect;
An intersection search circuit for determining a three-dimensional coordinate of the intersection with respect to a set of points determined to intersect;
For yet another range cross-range image, determine an axis for each reflection point, check if the axis passes the intersection, and if so, the point and the point on each image for the intersection. An intersection-passing-type corresponding point determination circuit that determines that the pair corresponds, and otherwise does not correspond;
The radar apparatus according to claim 7, further comprising a three-dimensional shape construction circuit that constructs a target three-dimensional shape based on information of the intersection passing type corresponding point determination circuit. Target shape data storage means for storing candidate target shape data;
Three-dimensional shape verification that outputs similar candidate targets by comparing the three-dimensional shape of the observation target restored by the three-dimensional shape restoration circuit with the shape data of the candidate target stored in the target shape data storage means The radar device according to claim 3, further comprising a circuit. Target shape data storage means for storing candidate target shape data;
RCS calculating means for applying electromagnetic field theory to the three-dimensional shape data of each candidate target accumulated in the target shape data and calculating a three-dimensional distribution of the reflection intensity;
A similar candidate target is selected by comparing the three-dimensional distribution of the reflection intensity of the observation target constructed by the reflection intensity three-dimensional distribution construction circuit with the three-dimensional distribution of the reflection intensity of each candidate target obtained by the RCS calculation means. The radar apparatus according to claim 2, further comprising a reflection intensity three-dimensional distribution matching circuit. An image radar apparatus that irradiates a target with radio waves and uses a reflected wave from the target to obtain target shape information as an ISAR radar image ,
A radar image collection device that is arranged at different positions, transmits and receives radio waves to and from the target, collects the radar image of the target, and estimates the presence direction of the target with reference to the radar position;
A reception-only radar image acquisition device that obtains a target radar image and a range vector related to the radar image using a signal reflected from the target irradiated from a predetermined radar image acquisition device;
A corresponding point determination circuit for determining a correspondence between each reflection point on the output image obtained from the radar image acquisition device or the reception-only radar image acquisition device;
The target three-dimensional shape is restored from the corresponding point determination result that is the output of the corresponding point determination circuit, the radar image that is the output of each radar image acquisition device or the reception-only radar image acquisition device, and the target presence direction 3 A radar apparatus comprising: a dimensional shape restoration circuit. Rotational motion storage means for storing rotational motion information for each candidate target;
A candidate target whose rotational motion is similar by comparing the rotational motion history of the observation target for each time stored in the rotational motion history storage circuit with the rotational motion information for each candidate target stored in the rotational motion storage means The radar apparatus according to claim 6, further comprising: a rotary motion collating circuit that outputs. The radar image collection device is
A transmitter that generates high frequency pulses to irradiate the target;
A transmission / reception antenna that transmits and receives high-frequency pulses generated by the transmitter;
A receiver that receives and detects a part of the high-frequency pulse reflected and scattered by the target via the transmitting and receiving antenna;
Radar image reproducing means for generating a radar image to be observed based on a received signal obtained by the receiver;
14. The radar according to claim 1, further comprising: a range vector calculating unit that obtains a target existence direction as a unit vector from a direction of arrival of the received signal with reference to a position of the radar image collection device. apparatus. The radar image collection device is
A receiver that receives and detects a part of the high-frequency pulse reflected and scattered by the target via a transmitting and receiving antenna;
Radar image reproducing means for generating a radar image to be observed based on a received signal obtained by the receiver;
And a Bister range vector calculating means for estimating a unit vector in the range direction from the arrival direction of the received signal and the irradiation direction of the radar image acquisition device that has transmitted to obtain the received signal. Item 14. The radar device according to any one of Items 1 to 13. Transmitter for generating high-frequency pulses to be irradiated to a target, transmission / reception antenna for transmitting / receiving high-frequency pulses generated by the transmitter, and receiving and detecting a part of the high-frequency pulses reflected and scattered by the target via the transmission / reception antenna Radar image reproduction means for generating a radar image to be observed as an ISAR radar image based on a received signal obtained by the receiver, a range vector calculation for obtaining a target direction as a unit vector from the direction of arrival of the received signal Means, a radar image history accumulating means for accumulating a radar image as an output of the radar image reproducing means that changes every moment according to the relative motion between the radar and the target, and the range vector that changes every moment according to the relative motion between the radar and the target. A movement record having range vector history storage means for storing a calculation result of a range vector as an output of the calculation means. And da image collection apparatus,
A corresponding point determination circuit for determining a corresponding point from a radar image at each time as an output of the mobile radar image collection device;
A three-dimensional shape restoration circuit for restoring the target three-dimensional shape from the corresponding point determination result of the corresponding point determination circuit, the range vector history and the radar image history as the output of the mobile radar image acquisition device. A characteristic radar device.

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