JP2004061332A - Radar signal processor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a radar signal processor wherein a blurring or spreading of an image is removed by reducing the error in phase corrective amount calculation owing to a wobbling of detected reference point frequency. <P>SOLUTION: Super-resolution processing is performed by using a sectional super-resolution processing circuit 14 in the time direction of received signals, thereby obtaining a waveform having frequency and amplitude with improved frequency resolution. With respect to the waveform having the frequency and amplitude obtained by the processing circuit 14, a data cut-out circuit 15 cuts out data on areas where each amplitude value exceeds a threshold set by a threshold setting circuit 16. A local maximum point frequency detection circuit 17 detects all the local maximum points with respect to the cut-out waveforms of the frequency and amplitude, to calculate the then frequencies. A mean frequency detection circuit 18 detects, as a reference point frequency, the mean value of frequencies at all the local maximum points detected by the detection circuit 17. <P>COPYRIGHT: (C)2004,JPO

Description

【００１１】
振幅値最大検出回路１０で各区分周波数分析番号ｋに対し、振幅Ａ_ｍ ^ｋが最大値をとる時の周波数を検出し、それを基準点周波数ｆ^ｋとすると、時間ｔ_ｋと基準点周波数ｆ^ｋの関係は図１５（ｃ）のプロットのようになる。平滑化回路１１で図１５（ｃ）のプロットに対し、平滑化を行うと図１５（ｃ）の実線のような波形が得られ、時間ｔ_ｋと周波数ｆ^’　ｋの関係は“数２”で表される。
【００１２】
【数２】

【００１３】
位相補正量算出回路１２では、位相補正量Ｗ_ｊを“数３”で算出する。
【００１４】
【数３】

【００１５】
位相補正回路１３では、Ｓ_ｉ，ｊ　の位相を位相補正量Ｗ_ｊを用いて“数４”で補正する。但し、時間による位相ずれが補正された目標受信信号ＲＤをＳ’_ｉ，ｊ　と定義する。
【００１６】
【数４】

【００１７】
【発明が解決しようとする課題】
上記のような従来のレーダ信号処理装置では、区分周波数分析後の周波数と振幅の波形が多峰で、かつ振幅値が最大となる峰の位置が時間毎に大きく変動するような場合、検出した基準点周波数がふらついて正確な位相補正量を算出することができず、画像がぼけたり、にじんだりするという課題があった。
【００１８】
この発明はかかる課題を解決するためになされたもので、検出した基準点周波数がふらついて正確な位相補正量を算出することができず、画像がぼけたり、にじんだりするということを防止するレーダ信号処理装置を得ることを目的とする。
【００１９】
【課題を解決するための手段】
第１の発明によるレーダ信号処理装置は、位相補正手段を、距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納する格納手段、上記格納手段より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理手段、上記区分超解像処理手段により得られた周波数と振幅の波形を閾値に基づいて切り出すデータ切り出し手段、当該切り出された周波数と振幅の波形について極大となる点を検出し、その極大となる点の周波数を算出する極大点周波数検出手段、上記極大点周波数検出手段により検出された周波数の平均値を基準点周波数とする平均周波数検出手段とにより構成したものである。
【００２０】
第２の発明によるレーダ信号処理装置は、第１の発明において上記位相補正手段に、上記平均周波数検出手段により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化手段、上記平滑化手段により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出手段、上記位相補正量算出手段により算出された位相補正量を用いて上記格納手段から出力された目標受信信号の位相を補正する位相補正回路とを具備したものである。
【００２１】
第３の発明によるレーダ信号処理装置は、第１の発明において上記位相補正手段を、上記距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納するバッファ回路、上記バッファ回路より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理回路、上記区分超解像処理回路で得られた周波数と振幅の波形についてデータを切り出すデータ切り出し回路、上記データ切り出し回路でデータを切り出す際に必要な閾値を設定する閾値設定回路、上記データ切り出し回路により切り出された周波数と振幅の波形について極大となる点を検出しその時の周波数を算出する極大点周波数検出回路、上記極大点周波数検出回路により検出された周波数の平均値を基準点周波数とする平均周波数検出回路、上記平均周波数検出回路により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化回路、上記平滑化回路により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出回路、上記位相補正量算出回路により算出された位相補正量を用いて上記バッファ回路から出力された目標受信信号の位相を補正する位相補正回路とにより構成したものである。
【００２２】
第４の発明によるレーダ信号処理装置は、位相補正手段を、距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納する格納手段、上記格納手段より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理手段、上記区分超解像処理手段により得られた周波数と振幅の波形を閾値に基づいて切り出すデータ切り出し手段、当該切り出された周波数と振幅の波形について極大となる点を検出し、その極大となる点の周波数を算出する極大点周波数検出手段、上記極大点周波数検出手段により検出された周波数の中心値を基準点周波数とする中心周波数検出手段とにより構成したものである。
【００２３】
第５の発明によるレーダ信号処理装置は、第４の発明において上記位相補正手段に、上記中心周波数検出手段により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化手段、上記平滑化手段により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出手段、上記位相補正量算出手段により算出された位相補正量を用いて上記格納手段から出力された目標受信信号の位相を補正する位相補正回路とを具備したものである。
【００２４】
第６の発明によるレーダ信号処理装置は、第４の発明において上記位相補正手段を、上記距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納するバッファ回路、上記バッファ回路より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理回路、上記区分超解像処理回路で得られた周波数と振幅の波形についてデータを切り出すデータ切り出し回路、上記データ切り出し回路でデータを切り出す際に必要な閾値を設定する閾値設定回路、上記データ切り出し回路により切り出された周波数と振幅の波形について極大となる点を検出しその時の周波数を算出する極大点周波数検出回路、上記極大点周波数検出回路により検出された周波数の中心値を基準点周波数とする中心周波数検出回路、上記中心周波数検出回路により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化回路、上記平滑化回路により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出回路、上記位相補正量算出回路により算出された位相補正量を用いて上記バッファ回路から出力された目標受信信号の位相を補正する位相補正回路とにより構成したものである。
【００２５】
第７の発明によるレーダ信号処理装置は、位相補正手段を、距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納する格納手段、上記格納手段より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理手段、上記区分超解像処理手段により得られた周波数と振幅の波形を閾値に基づいて切り出すデータ切り出し手段、当該切り出された周波数と振幅の波形について極大となる点を検出し、その極大となる点の周波数を算出する極大点周波数検出手段、上記極大点周波数検出手段により検出された周波数の最小値を基準点周波数とする最小周波数検出手段とにより構成したものである。
【００２６】
第８の発明によるレーダ信号処理装置は、第７の発明において上記位相補正手段に、上記最小周波数検出手段により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化手段、上記平滑化手段により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出手段、上記位相補正量算出手段により算出された位相補正量を用いて上記格納手段から出力された目標受信信号の位相を補正する位相補正回路とを具備したものである。
【００２７】
第９の発明によるレーダ信号処理装置は、第７の発明において上記位相補正手段を、上記距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納するバッファ回路、上記バッファ回路より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理回路、上記区分超解像処理回路で得られた周波数と振幅の波形についてデータを切り出すデータ切り出し回路、上記データ切り出し回路でデータを切り出す際に必要な閾値を設定する閾値設定回路、上記データ切り出し回路により切り出された周波数と振幅の波形について極大となる点を検出しその時の周波数を算出する極大点周波数検出回路、上記極大点周波数検出回路により検出された周波数の最小値を基準点周波数とする最小周波数検出回路、上記最小周波数検出回路により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化回路、上記平滑化回路により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出回路、上記位相補正量算出回路により算出された位相補正量を用いて上記バッファ回路から出力された目標受信信号の位相を補正する位相補正回路とにより構成したものである。
【００２８】
第１０の発明によるレーダ信号処理装置は、位相補正手段を、距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納する格納手段、上記格納手段より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理手段、上記区分超解像処理手段により得られた周波数と振幅の波形を閾値に基づいて切り出すデータ切り出し手段、当該切り出された周波数と振幅の波形について極大となる点を検出し、その極大となる点の周波数を算出する極大点周波数検出手段、上記極大点周波数検出手段により検出された周波数の最大値を基準点周波数とする最大周波数検出手段とにより構成したものである。
【００２９】
第１１の発明によるレーダ信号処理装置は、第１０の発明において上記位相補正手段に、上記最大周波数検出手段により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化手段、上記平滑化手段により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出手段、上記位相補正量算出手段により算出された位相補正量を用いて上記格納手段から出力された目標受信信号の位相を補正する位相補正回路とを具備したものである。
【００３０】
第１２の発明によるレーダ信号処理装置は、第１０の発明において上記位相補正手段を、上記距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納するバッファ回路、上記バッファ回路より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理回路、上記区分超解像処理回路で得られた周波数と振幅の波形についてデータを切り出すデータ切り出し回路、上記データ切り出し回路でデータを切り出す際に必要な閾値を設定する閾値設定回路、上記データ切り出し回路により切り出された周波数と振幅の波形について極大となる点を検出しその時の周波数を算出する極大点周波数検出回路、上記極大点周波数検出回路により検出された周波数の最大値を基準点周波数とする最大周波数検出回路、上記最大周波数検出回路により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化回路、上記平滑化回路により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出回路、上記位相補正量算出回路により算出された位相補正量を用いて上記バッファ回路から出力された目標受信信号の位相を補正する位相補正回路とにより構成したものである。
【００３１】
第１３の発明によるレーダ信号処理装置は、位相補正手段を、距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納する格納手段、上記格納手段より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理手段、上記区分超解像処理手段により得られた周波数と振幅の波形を閾値に基づいて切り出すデータ切り出し手段、当該切り出された周波数と振幅の波形について極大となる点を検出し、その極大となる点の周波数を算出する極大点周波数検出手段、上記極大点周波数検出手段により検出された周波数の中央値を基準点周波数とする中央周波数検出手段とにより構成したものである。
【００３２】
第１４の発明によるレーダ信号処理装置は、第１３の発明において上記位相補正手段に、上記中央周波数検出手段により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化手段、上記平滑化手段により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出手段、上記位相補正量算出手段により算出された位相補正量を用いて上記格納手段から出力された目標受信信号の位相を補正する位相補正回路とを具備したものである。
【００３３】
第１５の発明によるレーダ信号処理装置は、第１３の発明において上記位相補正手段を、上記距離補正手段により補正された目標受信信号及びレーダと目標重心との初期距離を格納するバッファ回路、上記バッファ回路より出力されたレーダと目標重心との初期距離における目標受信信号を時間方向に小区間で超解像処理する区分超解像処理回路、上記区分超解像処理回路で得られた周波数と振幅の波形についてデータを切り出すデータ切り出し回路、上記データ切り出し回路でデータを切り出す際に必要な閾値を設定する閾値設定回路、上記データ切り出し回路により切り出された周波数と振幅の波形について極大となる点を検出しその時の周波数を算出する極大点周波数検出回路、上記極大点周波数検出回路により検出された周波数の中央値を基準点周波数とする中央周波数検出回路、上記中央周波数検出回路により検出された基準点周波数の時間方向に対する軌跡を平滑化する平滑化回路、上記平滑化回路により平滑化された基準点周波数の時間方向に対する軌跡から位相補正量を算出する位相補正量算出回路、上記位相補正量算出回路により算出された位相補正量を用いて上記バッファ回路から出力された目標受信信号の位相を補正する位相補正回路とにより構成したものである。
【００３４】
【発明の実施の形態】
実施の形態１．
図１は、図１３に示すレーダ信号処理装置におけるこの発明の位相補正部の実施の一形態を示すものである。図において、４，ＲＳ，ＲＧ及びＲＤは図１３及び図１４と同じである。また、図において、８，１１，１２，１３及びＧＳは図１４と同じである。１４はバッファ回路８より出力されたレーダと目標重心との初期距離ＲＧにおける目標受信信号を時間方向に小区間で超解像処理する区分超解像処理回路、１５は区分超解像処理回路１４で得られた周波数と振幅の波形についてデータを切り出すデータ切り出し回路、１６はデータ切り出し回路１５でデータを切り出す際に必要な閾値を設定する閾値設定回路、１７はデータ切り出し回路１５で切り出された周波数と振幅の波形について極大となる点を検出しその時の周波数を算出する極大点周波数検出回路、１８は極大点周波数検出回路１７で検出された周波数の平均値を基準点周波数とする平均周波数検出回路である。
【００３５】
次に、上記図１のように構成された位相補正部４の動作について説明する。距離補正部３から入力された時間による距離ずれが補正された目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧはバッファ回路８に格納され、目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳとして出力される。
【００３６】
このレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳは区分超解像処理回路１４で時間方向に小区間で超解像処理された後、得られた周波数と振幅の波形に対してデータ切り出し回路１５で各振幅値が閾値設定回路１６で設定した閾値を越える領域についてデータが切り出される。なお、超解像処理とは、例えば、ＭＥＭ（Ｍａｘｉｍｕｍ　Ｅｎｔｒｏｐｙ　Ｍｅｔｈｏｄ）、ＭＵＳＩＣ（Ｍｕｌｔｉｐｌｅ　Ｓｉｇｎａｌ　Ｃｌａｓｓｉｆｉｃａｔｉｏｎ）等の超高分解能な周波数推定処理をさす。
【００３７】
閾値設定回路１６では、例えば、メインローブレベルとサイドローブレベルの間に一定の閾値を設定する固定スレッショルドやアダプティブに閾値を設定するＣＦＡＲ（Ｃｏｎｓｔａｎｔ　Ｆａｌｓｅ　Ａｌａｒｍ　Ｒａｔｅ）等を用いて、各区分超解像処理後の波形毎に閾値を設定する。極大点周波数検出回路１７ではデータ切り出し回路１５で切り出された周波数と振幅の波形について全ての極大点を検出し、その時の周波数を算出する。
【００３８】
平均周波数検出回路１８では、極大点周波数検出回路１７で算出された全極大点における周波数に対し、それらの平均周波数を基準点周波数として検出した後、平滑化回路１１に出力する。
【００３９】
平滑化回路１１では、基準点周波数の時間方向に対する軌跡を平滑化し、平滑化された軌跡から位相補正量算出回路１２で位相補正量を算出する。位相補正回路１３は位相補正量算出回路１２で算出した位相補正量を用いてバッファ回路８から出力された時間による距離ずれが補正された目標受信信号ＲＳの位相を補正し、時間による位相ずれが補正された目標受信信号ＲＤとして周波数分析部５へ出力する。
【００４０】
次に、上記図１のように構成された位相補正部４を図１５，図６，図７及び図８を用いて説明する。図１５は位相補正部４の処理方法、図６は区分超解像処理回路１４の動作を示した図、図７は極大点周波数検出回路１７における極大点周波数の検出方法を示した図、図８は平均周波数検出回路１８における基準点周波数の検出方法を示した図である。
【００４１】
時間による距離ずれが補正された目標受信信号ＲＳをＳ_ｉ，ｊ　（ここで、ｉはレンジビン番号、ｊはパルスヒット番号、ｉ，ｊは自然数である。）、レーダと目標重心との初期距離ＲＧの存在するレンジビン番号をｒと定義するとレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳはＳ_ｒ，ｊと表され、図１５（ａ）のような波形が得られる。Ｓ_ｒ，ｊに対し、区分超解像処理回路１４で時間方向（パルスヒット方向）に小区間で超解像処理を行うと図１５（ｂ）のような波形が得られ、周波数ｆ_ｍと振幅Ａ_ｍ ^ｋの関係（ここで、ｋは区分超解像処理番号、ｍは周波数ビン番号、ｋ，ｍは自然数である。）は“数１”で表される。
【００４２】
各区分超解像処理番号ｋにおいて、図６（ａ）のような受信信号を区分超解像処理回路１４で超解像処理すると、図６（ｂ）のように周波数分解能の向上した波形を得ることができる。
【００４３】
今、仮に区分周波数分析回路９を用いた場合、対象となる受信信号の観測時間をＴとすると、周波数分解能（理論分解能）Δｆは“数５”で与えられる。
【００４４】
【数５】

【００４５】
ここで、区分超解像処理回路１４を用いれば、対象となる受信信号の観測時間がＴであっても、“数５”で定義される理論分解能以上の周波数分解能を得ることができる。
【００４６】
例えば、区分超解像処理回路１４において“数５”で定義される理論分解能の半分の周波数分解能が得られるように超解像処理した場合、周波数分解能Δｆ’　は“数６”で与えられ、周波数分解能が“数５”に比べ２倍向上することがわかる。従って、後段の極大点周波数検出回路１７において極大点周波数の検出精度が向上する。
【００４７】
【数６】

【００４８】
各区分超解像処理番号ｋにおいて周波数ｆ_ｍと振幅Ａ_ｍ ^ｋの波形は図７（ａ）のように表される。図７（ｂ）では、図７（ａ）で表される波形に対し、各振幅値が閾値設定回路１６で設定した閾値（例えば、図７（ｂ）中の一点破線ｕ）を越える周波数領域についてデータ切り出し回路１５でデータ切り出しを行い、次に切り出された周波数領域について極大点周波数検出回路１７で全ての極大点を検出し、その時の周波数ｆ’_ｎ ^ｋ（ここで、ｎ＝１，・・・，Ｎであり、ｎは極大点番号、Ｎは極大点数、ｎ，Ｎは自然数である。）を算出する。
【００４９】
平均周波数検出回路１８では、図８のように極大点周波数検出回路１７で検出された極大点周波数ｆ’_ｎ ^ｋを用いて、“数７”で基準点周波数ｆ^ｋを算出する。
【００５０】
【数７】

【００５１】
時間ｔ_ｋと基準点周波数ｆ^ｋの関係は図１５（ｃ）のプロットのようになる。平滑化回路１１で図１５（ｃ）のプロットに対し、平滑化を行うと図１５（ｃ）の実線のような波形が得られ、時間ｔ_ｋと周波数ｆ^’　ｋの関係は“数２”で表される。
【００５２】
位相補正量算出回路１２では、位相補正量Ｗ_ｊを“数３”で算出する。
【００５３】
位相補正回路１３では、Ｓ_ｉ，ｊ　の位相を位相補正量Ｗ_ｊを用いて“数４”で補正する。但し、時間による位相ずれが補正された目標受信信号ＲＤをＳ’_ｉ，ｊ　と定義する。
【００５４】
実施の形態２．
図２に示される実施の形態では、上記実施の形態１における位相補正部４の基準点周波数検出手段として、平均周波数検出回路１８を極大点周波数検出回路１７で検出された周波数の中心値を基準点周波数とする中心周波数検出回路１９に置き換えている。
【００５５】
このような実施態様によれば、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、極大点の周波数のみに着目して基準点周波数を決定するため、波形の振幅値に依存しない安定した基準点周波数を検出することができる。更に、極大点の周波数から中心周波数を検出するので、計算量の削減が可能である。
【００５６】
次に、上記図２のように構成された位相補正部４の動作について説明する。距離補正部３から入力された時間による距離ずれが補正された目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧはバッファ回路８に格納され、目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳとして出力される。
【００５７】
このレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳは区分超解像処理回路１４で時間方向に小区間で超解像処理された後、得られた周波数と振幅の波形に対してデータ切り出し回路１５で各振幅値が閾値設定回路１６で設定した閾値を越える領域についてデータが切り出される。なお、超解像処理とは、例えば、ＭＥＭ（Ｍａｘｉｍｕｍ　Ｅｎｔｒｏｐｙ　Ｍｅｔｈｏｄ）、ＭＵＳＩＣ（Ｍｕｌｔｉｐｌｅ　Ｓｉｇｎａｌ　Ｃｌａｓｓｉｆｉｃａｔｉｏｎ）等の超高分解能な周波数推定処理をさす。
【００５８】
閾値設定回路１６では、例えば、メインローブレベルとサイドローブレベルの間に一定の閾値を設定する固定スレッショルドやアダプティブに閾値を設定するＣＦＡＲ（Ｃｏｎｓｔａｎｔ　Ｆａｌｓｅ　Ａｌａｒｍ　Ｒａｔｅ）等を用いて、各区分超解像処理後の波形毎に閾値を設定する。極大点周波数検出回路１７ではデータ切り出し回路１５で切り出された周波数と振幅の波形について全ての極大点を検出し、その時の周波数を算出する。
【００５９】
中心周波数検出回路１９では、極大点周波数検出回路１７で算出された全極大点における周波数に対し、それらの中心周波数を基準点周波数として検出した後、平滑化回路１１に出力する。
【００６０】
平滑化回路１１では、基準点周波数の時間方向に対する軌跡を平滑化し、平滑化された軌跡から位相補正量算出回路１２で位相補正量を算出する。位相補正回路１３は位相補正量算出回路１２で算出した位相補正量を用いてバッファ回路８から出力された時間による距離ずれが補正された目標受信信号ＲＳの位相を補正し、時間による位相ずれが補正された目標受信信号ＲＤとして周波数分析部５へ出力する。
【００６１】
次に、上記図２のように構成された位相補正部４を図７及び図９を用いて説明する。図９は中心周波数検出回路１９における基準点周波数の検出方法を示した図である。各区分超解像処理番号ｋにおいて周波数ｆ_ｍと振幅Ａ_ｍ ^ｋの波形は図７（ａ）のように表される。図７（ｂ）では、図７（ａ）で表される波形に対し、各振幅値が閾値設定回路１６で設定した閾値（例えば、図７（ｂ）中の一点破線ｕ）を越える周波数領域についてデータ切り出し回路１５でデータ切り出しを行い、次に切り出された周波数領域について極大点周波数検出回路１７で全ての極大点を検出し、その時の周波数ｆ’_ｎ ^ｋ（ここで、ｎ＝１，・・・，Ｎであり、ｎは極大点番号、Ｎは極大点数、ｎ，Ｎは自然数である。）を算出する。
【００６２】
中心周波数検出回路１９では、図９のように極大点周波数検出回路１７で検出された極大点周波数ｆ’_ｎ ^ｋを用いて、“数８”で基準点周波数ｆ^ｋを算出する。
【００６３】
【数８】

【００６４】
実施の形態３．
図３に示される実施の形態では、上記実施の形態１における位相補正部４の基準点周波数検出手段として、平均周波数検出回路１８を極大点周波数検出回路１７で検出された周波数の最小値を基準点周波数とする最小周波数検出回路２０に置き換えている。
【００６５】
このような実施態様によれば、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、極大点の周波数のみに着目して基準点周波数を決定するため、波形の振幅値に依存しない安定した基準点周波数を検出することができる。更に、極大点の周波数から最小周波数を検出するので、計算量の削減が可能である。
【００６６】
次に、上記図３のように構成された位相補正部４の動作について説明する。距離補正部３から入力された時間による距離ずれが補正された目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧはバッファ回路８に格納され、目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳとして出力される。
【００６７】
このレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳは区分超解像処理回路１４で時間方向に小区間で超解像処理された後、得られた周波数と振幅の波形に対してデータ切り出し回路１５で各振幅値が閾値設定回路１６で設定した閾値を越える領域についてデータが切り出される。なお、超解像処理とは、例えば、ＭＥＭ（Ｍａｘｉｍｕｍ　Ｅｎｔｒｏｐｙ　Ｍｅｔｈｏｄ）、ＭＵＳＩＣ（Ｍｕｌｔｉｐｌｅ　Ｓｉｇｎａｌ　Ｃｌａｓｓｉｆｉｃａｔｉｏｎ）等の超高分解能な周波数推定処理をさす。
【００６８】
閾値設定回路１６では、例えば、メインローブレベルとサイドローブレベルの間に一定の閾値を設定する固定スレッショルドやアダプティブに閾値を設定するＣＦＡＲ（Ｃｏｎｓｔａｎｔ　Ｆａｌｓｅ　Ａｌａｒｍ　Ｒａｔｅ）等を用いて、各区分超解像処理後の波形毎に閾値を設定する。極大点周波数検出回路１７ではデータ切り出し回路１５で切り出された周波数と振幅の波形について全ての極大点を検出し、その時の周波数を算出する。
【００６９】
最小周波数検出回路２０では、極大点周波数検出回路１７で算出された全極大点における周波数に対し、それらの最小周波数を基準点周波数として検出した後、平滑化回路１１に出力する。
【００７０】
平滑化回路１１では、基準点周波数の時間方向に対する軌跡を平滑化し、平滑化された軌跡から位相補正量算出回路１２で位相補正量を算出する。位相補正回路１３は位相補正量算出回路１２で算出した位相補正量を用いてバッファ回路８から出力された時間による距離ずれが補正された目標受信信号ＲＳの位相を補正し、時間による位相ずれが補正された目標受信信号ＲＤとして周波数分析部５へ出力する。
【００７１】
次に、上記図３のように構成された位相補正部４を図７及び図１０を用いて説明する。図１０は最小周波数検出回路２０における基準点周波数の検出方法を示した図である。各区分超解像処理番号ｋにおいて周波数ｆ_ｍと振幅Ａ_ｍ ^ｋの波形は図７（ａ）のように表される。図７（ｂ）では、図７（ａ）で表される波形に対し、各振幅値が閾値設定回路１６で設定した閾値（例えば、図７（ｂ）中の一点破線ｕ）を越える周波数領域についてデータ切り出し回路１５でデータ切り出しを行い、次に切り出された周波数領域について極大点周波数検出回路１７で全ての極大点を検出し、その時の周波数ｆ’_ｎ ^ｋ（ここで、ｎ＝１，・・・，Ｎであり、ｎは極大点番号、Ｎは極大点数、ｎ，Ｎは自然数である。）を算出する。
【００７２】
最小周波数検出回路２０では、図１０のように極大点周波数検出回路１７で検出された極大点周波数ｆ’_ｎ ^ｋを用いて、“数９”で基準点周波数ｆ^ｋを算出する。
【００７３】
【数９】

【００７４】
実施の形態４．
図４に示される実施の形態では、上記実施の形態１における位相補正部４の基準点周波数検出手段として、平均周波数検出回路１８を極大点周波数検出回路１７で検出された周波数の最大値を基準点周波数とする最大周波数検出回路２１に置き換えている。
【００７５】
このような実施態様によれば、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、極大点の周波数のみに着目して基準点周波数を決定するため、波形の振幅値に依存しない安定した基準点周波数を検出することができる。更に、極大点の周波数から最大周波数を検出するので、計算量の削減が可能である。
【００７６】
次に、上記図４のように構成された位相補正部４の動作について説明する。距離補正部３から入力された時間による距離ずれが補正された目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧはバッファ回路８に格納され、目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳとして出力される。
【００７７】
このレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳは区分超解像処理回路１４で時間方向に小区間で超解像処理された後、得られた周波数と振幅の波形に対してデータ切り出し回路１５で各振幅値が閾値設定回路１６で設定した閾値を越える領域についてデータが切り出される。なお、超解像処理とは、例えば、ＭＥＭ（Ｍａｘｉｍｕｍ　Ｅｎｔｒｏｐｙ　Ｍｅｔｈｏｄ）、ＭＵＳＩＣ（Ｍｕｌｔｉｐｌｅ　Ｓｉｇｎａｌ　Ｃｌａｓｓｉｆｉｃａｔｉｏｎ）等の超高分解能な周波数推定処理をさす。
【００７８】
閾値設定回路１６では、例えば、メインローブレベルとサイドローブレベルの間に一定の閾値を設定する固定スレッショルドやアダプティブに閾値を設定するＣＦＡＲ（Ｃｏｎｓｔａｎｔ　Ｆａｌｓｅ　Ａｌａｒｍ　Ｒａｔｅ）等を用いて、各区分超解像処理後の波形毎に閾値を設定する。極大点周波数検出回路１７ではデータ切り出し回路１５で切り出された周波数と振幅の波形について全ての極大点を検出し、その時の周波数を算出する。
【００７９】
最大周波数検出回路２１では、極大点周波数検出回路１７で算出された全極大点における周波数に対し、それらの最大周波数を基準点周波数として検出した後、平滑化回路１１に出力する。
【００８０】
平滑化回路１１では、基準点周波数の時間方向に対する軌跡を平滑化し、平滑化された軌跡から位相補正量算出回路１２で位相補正量を算出する。位相補正回路１３は位相補正量算出回路１２で算出した位相補正量を用いてバッファ回路８から出力された時間による距離ずれが補正された目標受信信号ＲＳの位相を補正し、時間による位相ずれが補正された目標受信信号ＲＤとして周波数分析部５へ出力する。
【００８１】
次に、上記図４のように構成された位相補正部４を図７及び図１１を用いて説明する。図１１は最大周波数検出回路２１における基準点周波数の検出方法を示した図である。各区分超解像処理番号ｋにおいて周波数ｆ_ｍと振幅Ａ_ｍ ^ｋの波形は図７（ａ）のように表される。図７（ｂ）では、図７（ａ）で表される波形に対し、各振幅値が閾値設定回路１６で設定した閾値（例えば、図７（ｂ）中の一点破線ｕ）を越える周波数領域についてデータ切り出し回路１５でデータ切り出しを行い、次に切り出された周波数領域について極大点周波数検出回路１７で全ての極大点を検出し、その時の周波数ｆ’_ｎ ^ｋ（ここで、ｎ＝１，・・・，Ｎであり、ｎは極大点番号、Ｎは極大点数、ｎ，Ｎは自然数である。）を算出する。
【００８２】
最大周波数検出回路２１では、図１１のように極大点周波数検出回路１７で検出された極大点周波数ｆ’_ｎ ^ｋを用いて、“数１０”で基準点周波数ｆ^ｋを算出する。
【００８３】
【数１０】

【００８４】
実施の形態５．
図５に示される実施の形態では、上記実施の形態１における位相補正部４の基準点周波数検出手段として、平均周波数検出回路１８を極大点周波数検出回路１７で検出された周波数の中央値を基準点周波数とする中央周波数検出回路２２に置き換えている。
【００８５】
このような実施態様によれば、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、極大点の周波数のみに着目して基準点周波数を決定するため、波形の振幅値に依存しない安定した基準点周波数を検出することができる。更に、極大点の周波数から中央周波数を検出するので、計算量の削減が可能である。
【００８６】
次に、上記図５のように構成された位相補正部４の動作について説明する。距離補正部３から入力された時間による距離ずれが補正された目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧはバッファ回路８に格納され、目標受信信号ＲＳ及びレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳとして出力される。
【００８７】
このレーダと目標重心との初期距離ＲＧにおける目標受信信号ＧＳは区分超解像処理回路１４で時間方向に小区間で超解像処理された後、得られた周波数と振幅の波形に対してデータ切り出し回路１５で各振幅値が閾値設定回路１６で設定した閾値を越える領域についてデータが切り出される。なお、超解像処理とは、例えば、ＭＥＭ（Ｍａｘｉｍｕｍ　Ｅｎｔｒｏｐｙ　Ｍｅｔｈｏｄ）、ＭＵＳＩＣ（Ｍｕｌｔｉｐｌｅ　Ｓｉｇｎａｌ　Ｃｌａｓｓｉｆｉｃａｔｉｏｎ）等の超高分解能な周波数推定処理をさす。
【００８８】
閾値設定回路１６では、例えば、メインローブレベルとサイドローブレベルの間に一定の閾値を設定する固定スレッショルドやアダプティブに閾値を設定するＣＦＡＲ（Ｃｏｎｓｔａｎｔ　Ｆａｌｓｅ　Ａｌａｒｍ　Ｒａｔｅ）等を用いて、各区分超解像処理後の波形毎に閾値を設定する。極大点周波数検出回路１７ではデータ切り出し回路１５で切り出された周波数と振幅の波形について全ての極大点を検出し、その時の周波数を算出する。
【００８９】
中央周波数検出回路２２では、極大点周波数検出回路１７で算出された全極大点における周波数に対し、それらの中央周波数を基準点周波数として検出した後、平滑化回路１１に出力する。
【００９０】
平滑化回路１１では、基準点周波数の時間方向に対する軌跡を平滑化し、平滑化された軌跡から位相補正量算出回路１２で位相補正量を算出する。位相補正回路１３は位相補正量算出回路１２で算出した位相補正量を用いてバッファ回路８から出力された時間による距離ずれが補正された目標受信信号ＲＳの位相を補正し、時間による位相ずれが補正された目標受信信号ＲＤとして周波数分析部５へ出力する。
【００９１】
次に、上記図５のように構成された位相補正部４を図７及び図１２を用いて説明する。図１２は中央周波数検出回路２２における基準点周波数の検出方法を示した図である。各区分超解像処理番号ｋにおいて周波数ｆ_ｍと振幅Ａ_ｍ ^ｋの波形は図７（ａ）のように表される。図７（ｂ）では、図７（ａ）で表される波形に対し、各振幅値が閾値設定回路１６で設定した閾値（例えば、図７（ｂ）中の一点破線ｕ）を越える周波数領域についてデータ切り出し回路１５でデータ切り出しを行い、次に切り出された周波数領域について極大点周波数検出回路１７で全ての極大点を検出し、その時の周波数ｆ’_ｎ ^ｋ（ここで、ｎ＝１，・・・，Ｎであり、ｎは極大点番号、Ｎは極大点数、ｎ，Ｎは自然数である。）を算出する。
【００９２】
中央周波数検出回路２２では、図１２のように極大点周波数検出回路１７で検出された極大点周波数ｆ’_ｎ ^ｋを用いて、“数１１”で基準点周波数ｆ^ｋを算出する。
【００９３】
【数１１】

【００９４】
“数１１”の右辺において極大点数Ｎが奇数である場合、（１＋Ｎ）／２＝ｎは整数となるため、該当する極大点周波数ｆ’_ｎ ^ｋは存在する。従って、容易に基準点周波数ｆ^ｋを算出することができる。しかし、極大点数Ｎが偶数である場合には、（１＋Ｎ）／２＝ｎは整数とならない（２で割り切れず、実数となる）ため、該当する極大点周波数ｆ’_ｎ ^ｋは存在しない。そこで、極大点数Ｎが偶数の場合には、例えば以下に示す方法のうち、いずれかの方法で基準点周波数ｆ^ｋを算出するようにすればよい。
【００９５】
“数１２”に（１＋Ｎ）／２の小数点以下を切り捨てる方法、“数１３”に（１＋Ｎ）／２の小数点以下を切り上げる方法、“数１４”に“数１２”と“数１３”の平均をとる方法を示す。なお、図１２では“数１４”を用いて基準点周波数ｆ^ｋを算出している。
【００９６】
【数１２】

【００９７】
【数１３】

【００９８】
【数１４】

【００９９】
【発明の効果】
第１から第３の発明は、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、設定した閾値に基づいてデータを切り出し、切り出した波形の極大点に着目して全極大点における周波数の平均値を基準点周波数として検出するので、周波数と振幅の波形が多峰で、かつ振幅値が最大となる峰の位置が時間毎に大きく変動するような場合でも変動の影響を受けにくく、安定して基準点周波数を検出することができ、画像のぼけやにじみを除去することができるという効果がある。
【０１００】
また、第４から第６の発明は、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、設定した閾値に基づいてデータを切り出し、切り出した波形の極大点に着目して全極大点における周波数の中心値を基準点周波数として検出するため、計算量を削減できる。更に、周波数と振幅の波形が多峰で、かつ振幅値が最大となる峰の位置が時間毎に大きく変動するような場合でも変動の影響を受けにくく、安定して基準点周波数を検出することができ、画像のぼけやにじみを除去することができるという効果がある。
【０１０１】
第７から第９の発明は、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、設定した閾値に基づいてデータを切り出し、切り出した波形の極大点に着目して全極大点における周波数の最小値を基準点周波数として検出するため、計算量を削減できる。更に、周波数と振幅の波形が多峰で、かつ振幅値が最大となる峰の位置が時間毎に大きく変動するような場合でも変動の影響を受けにくく、安定して基準点周波数を検出することができ、画像のぼけやにじみを除去することができるという効果がある。
【０１０２】
また、第１０から第１２の発明は、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、設定した閾値に基づいてデータを切り出し、切り出した波形の極大点に着目して全極大点における周波数の最大値を基準点周波数として検出するため、計算量を削減できる。更に、周波数と振幅の波形が多峰で、かつ振幅値が最大となる峰の位置が時間毎に大きく変動するような場合でも変動の影響を受けにくく、安定して基準点周波数を検出することができ、画像のぼけやにじみを除去することができるという効果がある。
【０１０３】
第１３から第１５の発明は、超解像処理によって周波数分解能が向上するため、極大点周波数の検出精度が向上する。また、区分超解像処理後の周波数と振幅の波形に対し、設定した閾値に基づいてデータを切り出し、切り出した波形の極大点に着目して全極大点における周波数の中央値を基準点周波数として検出するため、計算量を削減できる。更に、周波数と振幅の波形が多峰で、かつ振幅値が最大となる峰の位置が時間毎に大きく変動するような場合でも変動の影響を受けにくく、安定して基準点周波数を検出することができ、画像のぼけやにじみを除去することができるという効果がある。
【図面の簡単な説明】
【図１】この発明の実施の形態１を示す位相補正部の構成図である。
【図２】この発明の実施の形態２を示す位相補正部の構成図である。
【図３】この発明の実施の形態３を示す位相補正部の構成図である。
【図４】この発明の実施の形態４を示す位相補正部の構成図である。
【図５】この発明の実施の形態５を示す位相補正部の構成図である。
【図６】区分超解像処理回路の動作を示す図である。
【図７】極大点周波数検出回路における極大点周波数の検出方法を示す図である。
【図８】平均周波数検出回路における基準点周波数の検出方法を示す図である。
【図９】中心周波数検出回路における基準点周波数の検出方法を示す図である。
【図１０】最小周波数検出回路における基準点周波数の検出方法を示す図である。
【図１１】最大周波数検出回路における基準点周波数の検出方法を示す図である。
【図１２】中央周波数検出回路における基準点周波数の検出方法を示す図である。
【図１３】高分解能レーダ装置におけるレーダ信号処理装置の構成図である。
【図１４】従来の位相補正部の構成図である。
【図１５】位相補正部の処理方法を示す図である。
【符号の説明】
１　データインタフェース部、　２　パルス圧縮部、　３　距離補正部、　４位相補正部、　５　周波数分析部、　６　検波部、　７　表示器インタフェース部、　８　バッファ回路、　９　区分周波数分析回路、　１０　振幅値最大検出回路、　１１　平滑化回路、　１２　位相補正量算出回路、　１３　位相補正回路、　１４　区分超解像処理回路、　１５　データ切り出し回路、　１６　閾値設定回路、　１７　極大点周波数検出回路、　１８　平均周波数検出回路、　１９　中心周波数検出回路、　２０　最小周波数検出回路、　２１　最大周波数検出回路、　２２　中央周波数検出回路。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to correction of a phase shift of a target reception signal in a radar signal processing device of a high-resolution radar device, for example.
[0002]
[Prior art]
FIG. 13 is a configuration diagram of a radar signal processing device of a high-resolution radar device. In the drawing, reference numeral 1 denotes a data interface unit for converting a target reception signal input from the radar device into a data format that can be processed internally; A pulse compression unit that pulse-compresses the target reception signal converted by the unit 1, a distance correction unit 3 that corrects a distance shift due to time of the target reception signal that is pulse-compressed by the pulse compression unit 2, and a distance correction unit 3 that A phase corrector for correcting a phase shift due to time of the corrected target reception signal, a frequency analysis unit for separating a Doppler frequency of the target reception signal corrected by the phase correction unit, and a frequency analysis unit for frequency analysis A detector 7 converts the frequency spectrum of the target received signal into image data, and 7 adjusts the interface between the image data obtained by the detector 6 and the display. A display interface unit for generating image data, SM is a target reception signal input from the radar device, RS is a target reception signal whose distance deviation due to time has been corrected by the distance correction unit 3, and RG is an initial value between the radar and the target center of gravity. The distance and RD are target reception signals whose phase shift due to time has been corrected by the phase correction unit 4, and D is display image data.
[0003]
FIG. 14 is a configuration diagram of a conventional phase correction unit 4 in the radar signal processing device of FIG. 13, where RS, RG, RD and 4 are the same as those in FIG. 13, and 8 is output from the distance correction unit 3. The buffer circuit 9 stores the target reception signal RS in which the distance deviation due to the time has been corrected and the initial distance RG between the radar and the target center of gravity. 9 is the target reception at the initial distance RG between the radar and the target center of gravity output from the buffer circuit 8. A divided frequency analysis circuit for frequency-analyzing the signal in a small section in the time direction, and an amplitude for detecting a frequency having the maximum amplitude value with respect to the frequency and amplitude waveform obtained by the divided frequency analysis circuit 9 as a reference point frequency. A maximum value detection circuit, 11 is a smoothing circuit for smoothing the trajectory of the reference point frequency detected by the maximum amplitude value detection circuit 10 in the time direction, and 12 is smoothed by the smoothing circuit 11. A phase correction amount calculation circuit for calculating a phase correction amount from a locus of the reference point frequency in the time direction; and a phase correction amount calculation circuit for calculating a target correction signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit A phase correction circuit GS for correcting the phase is a target reception signal at an initial distance RG between the radar and the target center of gravity.
[0004]
Next, the operation will be described. The target reception signal SM input from the radar device is converted into a data format that can be internally processed by the data interface unit 1, pulse-compressed by the pulse compression unit 2, and corrected for a distance deviation due to time by the distance correction unit 3. The signal is output to the phase correction unit 4 as the target reception signal RS. Further, the distance correction unit 3 calculates an initial distance RG between the radar and the target center of gravity, and outputs the calculated initial distance RG to the phase correction unit 4. The phase correction unit 4 corrects the time-dependent phase shift of the target reception signal RS using the target reception signal RS whose distance shift due to time has been corrected and the initial distance RG between the radar and the target center of gravity, and performs frequency analysis as the target reception signal RD. Output to the unit 5.
[0005]
The target reception signal RD is converted into a frequency spectrum by being subjected to frequency analysis by the frequency analysis unit 5 and converted into image data by the detection unit 6, and then the display interface unit 7 adjusts the interface with the display. It is output as display image data D.
[0006]
Next, the operation of the phase correction unit 4 will be described. The target reception signal RS and the initial distance RG between the radar and the target center of gravity, the distance of which has been corrected by the time input from the distance correction unit 3, are stored in the buffer circuit 8, and the initial reception signal RS and the initial distance between the radar and the target center of gravity are stored. It is output as the target reception signal GS at the distance RG.
[0007]
The target reception signal GS at the initial distance RG between the radar and the target center of gravity is frequency-analyzed in a small section in the time direction by the division frequency analysis circuit 9, and the obtained maximum frequency and amplitude waveform is detected by the maximum amplitude value detection circuit 10. After detecting the frequency at which the amplitude value becomes the maximum as the reference point frequency, it is output to the smoothing circuit 11. The smoothing circuit 11 smoothes the locus of the reference point frequency in the time direction, and the phase correction amount calculating circuit 12 calculates the phase correction amount from the smoothed locus.
[0008]
The phase correction circuit 13 uses the phase correction amount calculated by the phase correction amount calculation circuit 12 to correct the phase of the target reception signal RS output from the buffer circuit 8 and corrected for the distance shift due to time. The signal is output to the frequency analysis unit 5 as the corrected target reception signal RD.
[0009]
Further, the phase correction unit 4 will be described with reference to FIG. FIG. 15 is a diagram illustrating a processing method of the phase correction unit 4. The target reception signal RS whose distance deviation due to time has been corrected is represented by S_{i, j}(Here, i is the range bin number, j is the pulse hit number, and i and j are natural numbers.) If the range bin number where the initial distance RG between the radar and the target center of gravity exists is defined as r, the distance between the radar and the target center of gravity is defined as r. The target reception signal GS at the initial distance RG is S_{r, j}And a waveform as shown in FIG. 15A is obtained. S_{r, j}On the other hand, when frequency analysis is performed in a small section in the time direction (pulse hit direction) by the divided frequency analysis circuit 9, a waveform as shown in FIG._mAnd amplitude A_m ^k(Where k is a division frequency analysis number, m is a frequency bin number, and k and m are natural numbers) are represented by “Equation 1”.
[0010]
(Equation 1)

[0011]
In the maximum amplitude value detection circuit 10, the amplitude A_m ^kDetects the frequency at which the maximum value is obtained, and uses it as the reference point frequency f^kThen time t_kAnd the reference point frequency f^kIs as shown in the plot of FIG. When the smoothing circuit 11 performs smoothing on the plot of FIG. 15C, a waveform as shown by a solid line in FIG._kAnd frequency f^{' k}Is represented by “Equation 2”.
[0012]
(Equation 2)

[0013]
In the phase correction amount calculation circuit 12, the phase correction amount W_jIs calculated by “Equation 3”.
[0014]
(Equation 3)

[0015]
In the phase correction circuit 13, S_{i, j}位相 phase correction amount W_jAnd is corrected by “Equation 4”. However, the target reception signal RD whose phase shift due to time has been corrected is represented by S ′._{i, j}Defined as.
[0016]
(Equation 4)

[0017]
[Problems to be solved by the invention]
In the conventional radar signal processing device as described above, when the waveform of the frequency and the amplitude after the division frequency analysis is multi-peak, and the position of the peak where the amplitude value is maximum fluctuates greatly with time, it is detected. There has been a problem that the reference point frequency fluctuates and an accurate phase correction amount cannot be calculated, and the image is blurred or blurred.
[0018]
The present invention has been made in order to solve such a problem, and a radar for preventing a detected reference point frequency from fluctuating, calculating an accurate phase correction amount, and preventing an image from being blurred or blurred. An object is to obtain a signal processing device.
[0019]
[Means for Solving the Problems]
A radar signal processing apparatus according to a first aspect of the present invention is a radar signal processing apparatus comprising: a storage unit configured to store a target reception signal corrected by the distance correction unit and an initial distance between the radar and the target center of gravity; and a radar output from the storage unit. Sectional super-resolution processing means for super-resolution processing of a target received signal at an initial distance from the target center of gravity in a small section in the time direction, based on a threshold and a frequency and amplitude waveform obtained by the above-described section super-resolution processing means Data extraction means for extracting, a maximum point frequency detection means for detecting a maximum point of the extracted frequency and amplitude waveforms, and calculating a frequency of the maximum point, a frequency detected by the maximum point frequency detection means And an average frequency detecting means using the average value of the reference frequency as a reference point frequency.
[0020]
According to a second aspect of the present invention, in the radar signal processing apparatus according to the first aspect, the phase correction means includes a smoothing means for smoothing a trajectory of the reference point frequency detected by the average frequency detection means in a time direction, and the smoothing means. A phase correction amount calculating means for calculating a phase correction amount from a locus in the time direction of the reference point frequency smoothed by the means, and the phase correction amount output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. A phase correction circuit for correcting the phase of the target reception signal.
[0021]
A radar signal processing device according to a third aspect of the present invention is the radar signal processing device according to the first aspect, wherein the phase correction means stores a target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity. A segmented super-resolution processing circuit for performing super-resolution processing of a target reception signal at an initial distance between a radar output from the circuit and a target center of gravity in a small section in a time direction, a frequency and an amplitude obtained by the above-described segmented super-resolution processing circuit A data extraction circuit for extracting data for the waveform of the data, a threshold setting circuit for setting a threshold required for extracting data by the data extraction circuit, and detection of a maximum point in the frequency and amplitude waveforms extracted by the data extraction circuit The maximum point frequency detection circuit that calculates the frequency at that time, the average value of the frequencies detected by the above maximum point frequency detection circuit An average frequency detection circuit as a reference point frequency, a smoothing circuit for smoothing a trajectory of the reference point frequency detected by the average frequency detection circuit in a time direction, and a time direction of the reference point frequency smoothed by the smoothing circuit A phase correction amount calculation circuit that calculates a phase correction amount from a trajectory for the phase correction circuit, a phase correction circuit that corrects the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit, and It is constituted by
[0022]
A radar signal processing device according to a fourth aspect of the present invention is a radar signal processing device comprising: a storage unit for storing a target reception signal corrected by the distance correction unit and an initial distance between the radar and the target center of gravity; and a radar output from the storage unit. Sectional super-resolution processing means for super-resolution processing of a target received signal at an initial distance from the target center of gravity in a small section in the time direction, based on a threshold and a frequency and amplitude waveform obtained by the above-described section super-resolution processing means Data extraction means for extracting, a maximum point frequency detection means for detecting a maximum point of the extracted frequency and amplitude waveforms, and calculating a frequency of the maximum point, a frequency detected by the maximum point frequency detection means And a center frequency detecting means that uses the center value of the reference frequency as a reference point frequency.
[0023]
According to a fifth aspect of the present invention, in the radar signal processing apparatus according to the fourth aspect, the phase correction means includes a smoothing means for smoothing a trajectory of the reference point frequency detected by the center frequency detection means in a time direction, and the smoothing means. A phase correction amount calculating means for calculating a phase correction amount from a locus in the time direction of the reference point frequency smoothed by the means, and the phase correction amount output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. A phase correction circuit for correcting the phase of the target reception signal.
[0024]
A radar signal processing apparatus according to a sixth aspect of the present invention is the radar signal processing apparatus according to the fourth aspect, wherein the phase correction means includes a buffer circuit for storing a target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity. A segmented super-resolution processing circuit for performing super-resolution processing of a target reception signal at an initial distance between a radar output from the circuit and a target center of gravity in a small section in a time direction, a frequency and an amplitude obtained by the above-described segmented super-resolution processing circuit A data extraction circuit for extracting data for the waveform of the data, a threshold setting circuit for setting a threshold required for extracting data by the data extraction circuit, and detection of a maximum point in the frequency and amplitude waveforms extracted by the data extraction circuit The maximum point frequency detection circuit for calculating the frequency at that time, the center value of the frequency detected by the maximum point frequency detection circuit A center frequency detection circuit as a reference point frequency, a smoothing circuit for smoothing a trajectory of the reference point frequency detected by the center frequency detection circuit in a time direction, and a time direction of the reference point frequency smoothed by the smoothing circuit A phase correction amount calculation circuit that calculates a phase correction amount from a trajectory for the phase correction circuit, a phase correction circuit that corrects the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit, and It is constituted by
[0025]
A radar signal processing device according to a seventh aspect of the present invention is a radar signal processing device comprising: a storage unit for storing a target reception signal corrected by the distance correction unit and an initial distance between the radar and the target center of gravity; and a radar output from the storage unit. Sectional super-resolution processing means for super-resolution processing of a target received signal at an initial distance from the target center of gravity in a small section in the time direction, based on a threshold and a frequency and amplitude waveform obtained by the above-described section super-resolution processing means Data extraction means for extracting, a maximum point frequency detection means for detecting a maximum point of the extracted frequency and amplitude waveforms, and calculating a frequency of the maximum point, a frequency detected by the maximum point frequency detection means And a minimum frequency detecting means that sets the minimum value of the reference point frequency as a reference point frequency.
[0026]
An radar signal processing apparatus according to an eighth aspect of the present invention is the radar signal processing apparatus according to the seventh aspect, wherein the phase correction means includes a smoothing means for smoothing a trajectory in the time direction of the reference point frequency detected by the minimum frequency detection means, A phase correction amount calculating means for calculating a phase correction amount from a locus in the time direction of the reference point frequency smoothed by the means, and the phase correction amount output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. A phase correction circuit for correcting the phase of the target reception signal.
[0027]
A radar signal processing apparatus according to a ninth aspect of the present invention is the radar signal processing apparatus according to the seventh aspect, wherein the phase correction means stores a target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity. A segmented super-resolution processing circuit for performing super-resolution processing of a target reception signal at an initial distance between a radar output from the circuit and a target center of gravity in a small section in a time direction, a frequency and an amplitude obtained by the above-described segmented super-resolution processing circuit A data extraction circuit for extracting data for the waveform of the data, a threshold setting circuit for setting a threshold required for extracting data by the data extraction circuit, and detection of a maximum point in the frequency and amplitude waveforms extracted by the data extraction circuit The maximum point frequency detection circuit that calculates the frequency at that time, the minimum value of the frequency detected by the above maximum point frequency detection circuit A minimum frequency detection circuit as a reference point frequency, a smoothing circuit for smoothing a locus of the reference point frequency detected by the minimum frequency detection circuit in a time direction, and a time direction of the reference point frequency smoothed by the smoothing circuit A phase correction amount calculation circuit that calculates a phase correction amount from a trajectory for the phase correction circuit, a phase correction circuit that corrects the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit, and It is constituted by
[0028]
A radar signal processing apparatus according to a tenth aspect of the present invention is a radar signal processing apparatus, comprising: a storage unit for storing a target reception signal corrected by the distance correction unit and an initial distance between the radar and the target center of gravity; and a radar output from the storage unit. Sectional super-resolution processing means for super-resolution processing of a target received signal at an initial distance from the target center of gravity in a small section in the time direction, based on a threshold and a frequency and amplitude waveform obtained by the above-described section super-resolution processing means Data extraction means for extracting, a maximum point frequency detection means for detecting a maximum point of the extracted frequency and amplitude waveforms, and calculating a frequency of the maximum point, a frequency detected by the maximum point frequency detection means And a maximum frequency detecting means that uses the maximum value of the reference frequency as a reference point frequency.
[0029]
An radar signal processing apparatus according to an eleventh aspect of the present invention is the radar signal processing apparatus according to the tenth aspect, wherein the phase correction means includes a smoothing means for smoothing a trajectory in the time direction of the reference point frequency detected by the maximum frequency detection means, A phase correction amount calculating means for calculating a phase correction amount from a locus in the time direction of the reference point frequency smoothed by the means, and the phase correction amount output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. A phase correction circuit for correcting the phase of the target reception signal.
[0030]
A radar signal processing apparatus according to a twelfth aspect of the present invention is the radar signal processing apparatus according to the tenth aspect, wherein the phase correction means includes a buffer circuit for storing a target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity. A segmented super-resolution processing circuit for performing super-resolution processing of a target reception signal at an initial distance between a radar output from the circuit and a target center of gravity in a small section in a time direction, a frequency and an amplitude obtained by the above-described segmented super-resolution processing circuit A data extraction circuit for extracting data for the waveform of the data, a threshold setting circuit for setting a threshold required for extracting data by the data extraction circuit, and detection of a maximum point in the frequency and amplitude waveforms extracted by the data extraction circuit The maximum point frequency detection circuit for calculating the frequency at that time, and the maximum frequency detected by the maximum point frequency detection circuit. A maximum frequency detection circuit having a value as a reference point frequency, a smoothing circuit for smoothing a trajectory in the time direction of the reference point frequency detected by the maximum frequency detection circuit, and a reference point frequency smoothed by the smoothing circuit. A phase correction amount calculation circuit that calculates a phase correction amount from a trajectory in the time direction, and a phase correction that corrects the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit And a circuit.
[0031]
A radar signal processing apparatus according to a thirteenth aspect of the present invention is a radar signal processing apparatus, comprising: a storage unit for storing a target reception signal corrected by the distance correction unit and an initial distance between the radar and the target center of gravity; and a radar output from the storage unit. Sectional super-resolution processing means for super-resolution processing of a target received signal at an initial distance from the target center of gravity in a small section in the time direction, based on a threshold and a frequency and amplitude waveform obtained by the above-described section super-resolution processing means Data extraction means for extracting, a maximum point frequency detection means for detecting a maximum point of the extracted frequency and amplitude waveforms, and calculating a frequency of the maximum point, a frequency detected by the maximum point frequency detection means And a center frequency detecting means that uses the median value of the reference point as a reference point frequency.
[0032]
According to a fourteenth aspect of the present invention, in the radar signal processing apparatus according to the thirteenth aspect, the phase correction means includes a smoothing means for smoothing a trajectory of the reference point frequency detected by the center frequency detection means in a time direction, and the smoothing means. A phase correction amount calculating means for calculating a phase correction amount from a locus in the time direction of the reference point frequency smoothed by the means, and the phase correction amount output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. A phase correction circuit for correcting the phase of the target reception signal.
[0033]
A radar signal processing apparatus according to a fifteenth aspect of the present invention is the radar signal processing apparatus according to the thirteenth aspect, wherein the phase correction means includes a buffer circuit for storing the target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity. A segmented super-resolution processing circuit for super-resolution processing of a target reception signal at an initial distance between a radar output from the circuit and a target center of gravity in a small section in a time direction, a frequency and an amplitude obtained by the above-described segmented super-resolution processing circuit A data extraction circuit for extracting data for the waveform of the data, a threshold setting circuit for setting a threshold required when data is extracted by the data extraction circuit, and detection of a maximum point in the frequency and amplitude waveforms extracted by the data extraction circuit The maximum point frequency detection circuit for calculating the frequency at that time, and the frequency detected by the maximum point frequency detection circuit. A central frequency detection circuit having a value as a reference point frequency, a smoothing circuit for smoothing a locus in the time direction of the reference point frequency detected by the central frequency detection circuit, and a reference point frequency smoothed by the smoothing circuit. A phase correction amount calculation circuit for calculating a phase correction amount from a trajectory in the time direction, and a phase correction for correcting the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit And a circuit.
[0034]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 shows an embodiment of the phase correction section of the present invention in the radar signal processing device shown in FIG. In the figure, 4, RS, RG and RD are the same as those in FIGS. In the figure, 8, 11, 12, 13 and GS are the same as in FIG. 14 is a segmented super-resolution processing circuit for super-resolution processing of a target reception signal at an initial distance RG between the radar output from the buffer circuit 8 and the target center of gravity in a small section in the time direction, and 15 is a segmented super-resolution processing circuit 14 A data cutout circuit for cutting out data on the waveform of the frequency and amplitude obtained in the above, 16 is a threshold setting circuit for setting a threshold necessary for cutting out data by the data cutout circuit 15, and 17 is a frequency cut out by the data cutout circuit 15 A maximum point frequency detection circuit for detecting a maximum point of the waveform of the amplitude and calculating the frequency at that time; and 18, an average frequency detection circuit using the average value of the frequencies detected by the maximum point frequency detection circuit 17 as a reference point frequency It is.
[0035]
Next, the operation of the phase correction unit 4 configured as shown in FIG. 1 will be described. The target reception signal RS and the initial distance RG between the radar and the target center of gravity, the distance of which has been corrected by the time input from the distance correction unit 3, are stored in the buffer circuit 8, and the initial reception signal RS and the initial distance between the radar and the target center of gravity are stored. It is output as the target reception signal GS at the distance RG.
[0036]
The target reception signal GS at the initial distance RG between the radar and the target center of gravity is subjected to super-resolution processing in a small section in the time direction by the segmented super-resolution processing circuit 14, and then data is obtained for the obtained frequency and amplitude waveforms. The cutout circuit 15 cuts out data in a region where each amplitude value exceeds the threshold set by the threshold setting circuit 16. Note that the super-resolution processing refers to an ultra-high-resolution frequency estimation processing such as MEM (Maximum Entropy Method), MUSIC (Multiple Signal Classification), or the like.
[0037]
The threshold setting circuit 16 uses, for example, a fixed threshold for setting a fixed threshold between the main lobe level and the side lobe level, a CFAR (Constant \ False \ Alarm \ Rate) for adaptively setting the threshold, and the like, and uses each section super-resolution. A threshold is set for each processed waveform. The local maximum frequency detecting circuit 17 detects all local maximum points for the frequency and amplitude waveforms cut out by the data cutout circuit 15 and calculates the frequency at that time.
[0038]
The average frequency detecting circuit 18 detects the average frequency of the frequencies at all the local maximum points calculated by the local maximum frequency detecting circuit 17 as a reference point frequency, and outputs the reference frequency to the smoothing circuit 11.
[0039]
The smoothing circuit 11 smoothes the locus of the reference point frequency in the time direction, and the phase correction amount calculating circuit 12 calculates the phase correction amount from the smoothed locus. The phase correction circuit 13 uses the phase correction amount calculated by the phase correction amount calculation circuit 12 to correct the phase of the target reception signal RS output from the buffer circuit 8 and corrected for the distance shift due to time. The signal is output to the frequency analysis unit 5 as the corrected target reception signal RD.
[0040]
Next, the phase corrector 4 configured as shown in FIG. 1 will be described with reference to FIGS. 15, 6, 7, and 8. FIG. 15 is a diagram illustrating a processing method of the phase correction unit 4, FIG. 6 is a diagram illustrating an operation of the segmented super-resolution processing circuit 14, and FIG. 7 is a diagram illustrating a method of detecting a maximum point frequency in the maximum point frequency detection circuit 17. FIG. 8 is a diagram showing a method of detecting the reference point frequency in the average frequency detection circuit 18.
[0041]
The target reception signal RS whose distance deviation due to time has been corrected is represented by S_{i, j}(Here, i is the range bin number, j is the pulse hit number, and i and j are natural numbers.) If the range bin number where the initial distance RG between the radar and the target center of gravity exists is defined as r, the distance between the radar and the target center of gravity is defined as r. The target reception signal GS at the initial distance RG is S_{r, j}And a waveform as shown in FIG. 15A is obtained. S_{r, j}On the other hand, when super-resolution processing is performed in a small section in the time direction (pulse hit direction) by the segmented super-resolution processing circuit 14, a waveform as shown in FIG._mAnd amplitude A_m ^k(Where k is a segmented super-resolution processing number, m is a frequency bin number, and k and m are natural numbers) are represented by “Equation 1”.
[0042]
At each segmented super-resolution processing number k, when the received signal as shown in FIG. 6A is subjected to super-resolution processing by the segmented super-resolution processing circuit 14, a waveform with improved frequency resolution as shown in FIG. Obtainable.
[0043]
Now, assuming that the observation time of the target received signal is T when the divided frequency analysis circuit 9 is used, the frequency resolution (theoretical resolution) Δf is given by “Equation 5”.
[0044]
(Equation 5)

[0045]
Here, if the segmented super-resolution processing circuit 14 is used, even if the observation time of the target received signal is T, a frequency resolution higher than the theoretical resolution defined by “Equation 5” can be obtained.
[0046]
For example, when the super-resolution processing is performed in the segmented super-resolution processing circuit 14 so as to obtain a frequency resolution that is half the theoretical resolution defined by “Equation 5”, the frequency resolution Δf ′ is given by “Equation 6”, It can be seen that the frequency resolution is doubled as compared with "Equation 5". Therefore, the detection accuracy of the maximum point frequency in the subsequent maximum point frequency detection circuit 17 is improved.
[0047]
(Equation 6)

[0048]
Frequency f at each segmented super-resolution processing number k_mAnd amplitude A_m ^kIs represented as shown in FIG. In FIG. 7B, the frequency domain in which each amplitude value exceeds the threshold value set by the threshold value setting circuit 16 (for example, the one-dot broken line u in FIG. 7B) with respect to the waveform shown in FIG. The data extraction circuit 15 performs data extraction, and the local maximum frequency detection circuit 17 detects all local maximum points in the extracted frequency region, and the frequency f ′ at that time is detected._n ^k(Here, n = 1,..., N, n is the maximum point number, N is the maximum point number, and n and N are natural numbers.)
[0049]
In the average frequency detection circuit 18, the maximum point frequency f ′ detected by the maximum point frequency detection circuit 17 as shown in FIG._n ^kAnd the reference point frequency f^kIs calculated.
[0050]
(Equation 7)

[0051]
Time t_kAnd the reference point frequency f^kIs as shown in the plot of FIG. When the smoothing circuit 11 performs smoothing on the plot of FIG. 15C, a waveform as shown by a solid line in FIG._kAnd frequency f^{' k}Is represented by “Equation 2”.
[0052]
In the phase correction amount calculation circuit 12, the phase correction amount W_jIs calculated by “Equation 3”.
[0053]
In the phase correction circuit 13, S_{i, j}位相 phase correction amount W_jAnd is corrected by “Equation 4”. However, the target reception signal RD whose phase shift due to time has been corrected is represented by S ′._{i, j}Defined as.
[0054]
Embodiment 2 FIG.
In the embodiment shown in FIG. 2, as the reference point frequency detecting means of the phase correction unit 4 in the first embodiment, the average frequency detecting circuit 18 uses the center value of the frequency detected by the local maximum frequency detecting circuit 17 as a reference. A center frequency detecting circuit 19 for setting a point frequency is replaced.
[0055]
According to such an embodiment, since the frequency resolution is improved by the super-resolution processing, the detection accuracy of the maximum point frequency is improved. In addition, for the frequency and amplitude waveforms after the segmented super-resolution processing, the reference point frequency is determined by focusing only on the frequency of the local maximum point. Can be. Further, since the center frequency is detected from the frequency of the local maximum point, the amount of calculation can be reduced.
[0056]
Next, the operation of the phase correction unit 4 configured as shown in FIG. 2 will be described. The target reception signal RS and the initial distance RG between the radar and the target center of gravity, the distance of which has been corrected by the time input from the distance correction unit 3, are stored in the buffer circuit 8, and the initial reception signal RS and the initial distance between the radar and the target center of gravity are stored. It is output as the target reception signal GS at the distance RG.
[0057]
The target reception signal GS at the initial distance RG between the radar and the target center of gravity is subjected to super-resolution processing in a small section in the time direction by the segmented super-resolution processing circuit 14, and then data is obtained for the obtained frequency and amplitude waveforms. The cutout circuit 15 cuts out data in a region where each amplitude value exceeds the threshold set by the threshold setting circuit 16. Note that the super-resolution processing refers to an ultra-high-resolution frequency estimation processing such as MEM (Maximum Entropy Method), MUSIC (Multiple Signal Classification), or the like.
[0058]
The threshold setting circuit 16 uses, for example, a fixed threshold for setting a fixed threshold between the main lobe level and the side lobe level, a CFAR (Constant \ False \ Alarm \ Rate) for adaptively setting the threshold, and the like, and uses each section super-resolution. A threshold is set for each processed waveform. The local maximum frequency detecting circuit 17 detects all local maximum points for the frequency and amplitude waveforms cut out by the data cutout circuit 15 and calculates the frequency at that time.
[0059]
The center frequency detecting circuit 19 detects the center frequencies of the frequencies at all the local maximum points calculated by the local maximum point frequency detecting circuit 17 as the reference point frequencies, and then outputs them to the smoothing circuit 11.
[0060]
The smoothing circuit 11 smoothes the locus of the reference point frequency in the time direction, and the phase correction amount calculating circuit 12 calculates the phase correction amount from the smoothed locus. The phase correction circuit 13 uses the phase correction amount calculated by the phase correction amount calculation circuit 12 to correct the phase of the target reception signal RS output from the buffer circuit 8 and corrected for the distance shift due to time. The signal is output to the frequency analysis unit 5 as the corrected target reception signal RD.
[0061]
Next, the phase corrector 4 configured as shown in FIG. 2 will be described with reference to FIGS. FIG. 9 is a diagram showing a method of detecting the reference point frequency in the center frequency detection circuit 19. Frequency f at each segmented super-resolution processing number k_mAnd amplitude A_m ^kIs represented as shown in FIG. In FIG. 7B, the frequency domain in which each amplitude value exceeds the threshold value set by the threshold value setting circuit 16 (for example, the one-dot broken line u in FIG. 7B) with respect to the waveform shown in FIG. The data extraction circuit 15 performs data extraction, and the local maximum frequency detection circuit 17 detects all local maximum points in the extracted frequency region, and the frequency f ′ at that time is detected._n ^k(Here, n = 1,..., N, n is the maximum point number, N is the maximum point number, and n and N are natural numbers.)
[0062]
In the center frequency detection circuit 19, the maximum point frequency f 'detected by the maximum point frequency detection circuit 17 as shown in FIG._n ^kAnd the reference point frequency f^kIs calculated.
[0063]
(Equation 8)

[0064]
Embodiment 3 FIG.
In the embodiment shown in FIG. 3, as the reference point frequency detecting means of the phase correction unit 4 in the first embodiment, the average frequency detecting circuit 18 uses the minimum value of the frequency detected by the local maximum frequency detecting circuit 17 as a reference. It is replaced by a minimum frequency detection circuit 20 which is a point frequency.
[0065]
According to such an embodiment, since the frequency resolution is improved by the super-resolution processing, the detection accuracy of the maximum point frequency is improved. In addition, for the frequency and amplitude waveforms after the segmented super-resolution processing, the reference point frequency is determined by focusing only on the frequency of the local maximum point. Can be. Furthermore, since the minimum frequency is detected from the frequency of the local maximum point, the calculation amount can be reduced.
[0066]
Next, the operation of the phase correction unit 4 configured as shown in FIG. 3 will be described. The target reception signal RS and the initial distance RG between the radar and the target center of gravity, the distance of which has been corrected by the time input from the distance correction unit 3, are stored in the buffer circuit 8, and the initial reception signal RS and the initial distance between the radar and the target center of gravity are stored. It is output as the target reception signal GS at the distance RG.
[0067]
The target reception signal GS at the initial distance RG between the radar and the target center of gravity is subjected to super-resolution processing in a small section in the time direction by the segmented super-resolution processing circuit 14, and then data is obtained for the obtained frequency and amplitude waveforms. The cutout circuit 15 cuts out data in a region where each amplitude value exceeds the threshold set by the threshold setting circuit 16. Note that the super-resolution processing refers to an ultra-high-resolution frequency estimation processing such as MEM (Maximum Entropy Method), MUSIC (Multiple Signal Classification), or the like.
[0068]
The threshold setting circuit 16 uses, for example, a fixed threshold for setting a fixed threshold between the main lobe level and the side lobe level, a CFAR (Constant \ False \ Alarm \ Rate) for adaptively setting the threshold, and the like, and uses each section super-resolution. A threshold is set for each processed waveform. The local maximum frequency detecting circuit 17 detects all local maximum points for the frequency and amplitude waveforms cut out by the data cutout circuit 15 and calculates the frequency at that time.
[0069]
The minimum frequency detection circuit 20 detects the minimum frequencies as the reference point frequencies for the frequencies at all the maximum points calculated by the maximum point frequency detection circuit 17, and outputs the detected frequencies to the smoothing circuit 11.
[0070]
The smoothing circuit 11 smoothes the locus of the reference point frequency in the time direction, and the phase correction amount calculating circuit 12 calculates the phase correction amount from the smoothed locus. The phase correction circuit 13 uses the phase correction amount calculated by the phase correction amount calculation circuit 12 to correct the phase of the target reception signal RS output from the buffer circuit 8 and corrected for the distance shift due to time. The signal is output to the frequency analysis unit 5 as the corrected target reception signal RD.
[0071]
Next, the phase corrector 4 configured as shown in FIG. 3 will be described with reference to FIGS. FIG. 10 is a diagram showing a method of detecting the reference point frequency in the minimum frequency detection circuit 20. Frequency f at each segmented super-resolution processing number k_mAnd amplitude A_m ^kIs represented as shown in FIG. In FIG. 7B, the frequency domain in which each amplitude value exceeds the threshold value set by the threshold value setting circuit 16 (for example, the one-dot broken line u in FIG. 7B) with respect to the waveform shown in FIG. The data extraction circuit 15 performs data extraction, and the local maximum frequency detection circuit 17 detects all local maximum points in the extracted frequency region, and the frequency f ′ at that time is detected._n ^k(Here, n = 1,..., N, n is the maximum point number, N is the maximum point number, and n and N are natural numbers.)
[0072]
In the minimum frequency detection circuit 20, the maximum point frequency f 'detected by the maximum point frequency detection circuit 17 as shown in FIG._n ^kAnd the reference point frequency f^kIs calculated.
[0073]
(Equation 9)

[0074]
Embodiment 4 FIG.
In the embodiment shown in FIG. 4, as the reference point frequency detecting means of the phase correction unit 4 in the first embodiment, the average frequency detecting circuit 18 uses the maximum value of the frequency detected by the maximum point frequency detecting circuit 17 as a reference. It is replaced by a maximum frequency detection circuit 21 which is a point frequency.
[0075]
According to such an embodiment, since the frequency resolution is improved by the super-resolution processing, the detection accuracy of the maximum point frequency is improved. In addition, for the frequency and amplitude waveforms after the segmented super-resolution processing, the reference point frequency is determined by focusing only on the frequency of the local maximum point. Can be. Further, since the maximum frequency is detected from the frequency of the maximum point, the amount of calculation can be reduced.
[0076]
Next, the operation of the phase correction unit 4 configured as shown in FIG. 4 will be described. The target reception signal RS and the initial distance RG between the radar and the target center of gravity, the distance of which has been corrected by the time input from the distance correction unit 3, are stored in the buffer circuit 8, and the initial reception signal RS and the initial distance between the radar and the target center of gravity are stored. It is output as the target reception signal GS at the distance RG.
[0077]
The target reception signal GS at the initial distance RG between the radar and the target center of gravity is subjected to super-resolution processing in a small section in the time direction by the segmented super-resolution processing circuit 14, and then data is obtained for the obtained frequency and amplitude waveforms. The cutout circuit 15 cuts out data in a region where each amplitude value exceeds the threshold set by the threshold setting circuit 16. Note that the super-resolution processing refers to an ultra-high-resolution frequency estimation processing such as MEM (Maximum Entropy Method), MUSIC (Multiple Signal Classification), or the like.
[0078]
The threshold setting circuit 16 uses, for example, a fixed threshold for setting a fixed threshold between the main lobe level and the side lobe level, a CFAR (Constant \ False \ Alarm \ Rate) for adaptively setting the threshold, and the like, and uses each section super-resolution. A threshold is set for each processed waveform. The local maximum frequency detecting circuit 17 detects all local maximum points for the frequency and amplitude waveforms cut out by the data cutout circuit 15 and calculates the frequency at that time.
[0079]
The maximum frequency detection circuit 21 detects the maximum frequencies as the reference point frequencies for the frequencies at all the maximum points calculated by the maximum point frequency detection circuit 17, and outputs the detected frequencies to the smoothing circuit 11.
[0080]
The smoothing circuit 11 smoothes the locus of the reference point frequency in the time direction, and the phase correction amount calculating circuit 12 calculates the phase correction amount from the smoothed locus. The phase correction circuit 13 uses the phase correction amount calculated by the phase correction amount calculation circuit 12 to correct the phase of the target reception signal RS output from the buffer circuit 8 and corrected for the distance shift due to time. The signal is output to the frequency analysis unit 5 as the corrected target reception signal RD.
[0081]
Next, the phase corrector 4 configured as shown in FIG. 4 will be described with reference to FIGS. FIG. 11 is a diagram showing a method of detecting the reference point frequency in the maximum frequency detection circuit 21. Frequency f at each segmented super-resolution processing number k_mAnd amplitude A_m ^kIs represented as shown in FIG. In FIG. 7B, the frequency domain in which each amplitude value exceeds the threshold value set by the threshold value setting circuit 16 (for example, the one-dot broken line u in FIG. 7B) with respect to the waveform shown in FIG. The data extraction circuit 15 performs data extraction, and the local maximum frequency detection circuit 17 detects all local maximum points in the extracted frequency region, and the frequency f ′ at that time is detected._n ^k(Here, n = 1,..., N, n is the maximum point number, N is the maximum point number, and n and N are natural numbers.)
[0082]
In the maximum frequency detection circuit 21, the maximum point frequency f 'detected by the maximum point frequency detection circuit 17 as shown in FIG._n ^kAnd the reference point frequency f^kIs calculated.
[0083]
(Equation 10)

[0084]
Embodiment 5 FIG.
In the embodiment shown in FIG. 5, as the reference point frequency detecting means of the phase correction unit 4 in the first embodiment, the average frequency detecting circuit 18 uses the median value of the frequency detected by the local maximum frequency detecting circuit 17 as a reference. It is replaced by a center frequency detection circuit 22 which is a point frequency.
[0085]
According to such an embodiment, since the frequency resolution is improved by the super-resolution processing, the detection accuracy of the maximum point frequency is improved. In addition, for the frequency and amplitude waveforms after the segmented super-resolution processing, the reference point frequency is determined by focusing only on the frequency of the local maximum point. Can be. Further, since the center frequency is detected from the frequency of the local maximum point, the amount of calculation can be reduced.
[0086]
Next, the operation of the phase correction unit 4 configured as shown in FIG. 5 will be described. The target reception signal RS and the initial distance RG between the radar and the target center of gravity, the distance of which has been corrected by the time input from the distance correction unit 3, are stored in the buffer circuit 8, and the initial reception signal RS and the initial distance between the radar and the target center of gravity are stored. It is output as the target reception signal GS at the distance RG.
[0087]
The target reception signal GS at the initial distance RG between the radar and the target center of gravity is subjected to super-resolution processing in a small section in the time direction by the segmented super-resolution processing circuit 14, and then data is obtained for the obtained frequency and amplitude waveforms. The cutout circuit 15 cuts out data in a region where each amplitude value exceeds the threshold set by the threshold setting circuit 16. Note that the super-resolution processing refers to an ultra-high-resolution frequency estimation processing such as MEM (Maximum Entropy Method), MUSIC (Multiple Signal Classification), or the like.
[0088]
The threshold setting circuit 16 uses, for example, a fixed threshold for setting a fixed threshold between the main lobe level and the side lobe level, a CFAR (Constant \ False \ Alarm \ Rate) for adaptively setting the threshold, and the like, and uses each section super-resolution. A threshold is set for each processed waveform. The local maximum frequency detecting circuit 17 detects all local maximum points for the frequency and amplitude waveforms cut out by the data cutout circuit 15 and calculates the frequency at that time.
[0089]
The center frequency detection circuit 22 detects the center frequencies of the frequencies at all the maximum points calculated by the maximum point frequency detection circuit 17 as the reference point frequencies, and outputs the reference frequencies to the smoothing circuit 11.
[0090]
The smoothing circuit 11 smoothes the locus of the reference point frequency in the time direction, and the phase correction amount calculating circuit 12 calculates the phase correction amount from the smoothed locus. The phase correction circuit 13 uses the phase correction amount calculated by the phase correction amount calculation circuit 12 to correct the phase of the target reception signal RS output from the buffer circuit 8 and corrected for the distance shift due to time. The signal is output to the frequency analysis unit 5 as the corrected target reception signal RD.
[0091]
Next, the phase corrector 4 configured as shown in FIG. 5 will be described with reference to FIGS. FIG. 12 is a diagram showing a method of detecting the reference point frequency in the center frequency detection circuit 22. Frequency f at each segmented super-resolution processing number k_mAnd amplitude A_m ^kIs represented as shown in FIG. In FIG. 7B, the frequency domain in which each amplitude value exceeds the threshold value set by the threshold value setting circuit 16 (for example, the one-dot broken line u in FIG. 7B) with respect to the waveform shown in FIG. The data extraction circuit 15 performs data extraction, and the local maximum frequency detection circuit 17 detects all local maximum points in the extracted frequency region, and the frequency f ′ at that time is detected._n ^k(Here, n = 1,..., N, n is the maximum point number, N is the maximum point number, and n and N are natural numbers.)
[0092]
In the center frequency detecting circuit 22, the local maximum frequency f 'detected by the local maximum frequency detecting circuit 17 as shown in FIG._n ^kAnd the reference point frequency f^kIs calculated.
[0093]
[Equation 11]

[0094]
If the number N of maximum points is an odd number on the right side of “Equation 11,” (1 + N) / 2 = n is an integer, and thus the corresponding maximum point frequency f ′_n ^kExists. Therefore, the reference point frequency f can be easily obtained.^kCan be calculated. However, when the maximum point number N is an even number, (1 + N) / 2 = n is not an integer (not a divisible by 2 but a real number), so the corresponding maximum point frequency f ′_n ^kDoes not exist. Therefore, when the maximum point number N is an even number, for example, the reference point frequency f^kMay be calculated.
[0095]
A method of rounding down the decimal point of (1 + N) / 2 to “Equation 12”, a method of rounding up the decimal point of (1 + N) / 2 to “Equation 13”, an average of “Equation 12” and “Equation 13” in “Equation 14” Here is how to take Note that in FIG. 12, the reference point frequency f is calculated using “Equation 14”.^kIs calculated.
[0096]
(Equation 12)

[0097]
(Equation 13)

[0098]
[Equation 14]

[0099]
【The invention's effect】
In the first to third inventions, since the frequency resolution is improved by the super-resolution processing, the detection accuracy of the maximum point frequency is improved. In addition, for the frequency and amplitude waveforms after the segmented super-resolution processing, data is cut out based on the set threshold, and the average value of the frequencies at all the maximum points is used as the reference point frequency, focusing on the local maximum points of the extracted waveform. Because it is detected, even if the waveform of frequency and amplitude is multi-peak and the position of the peak where the amplitude value is maximum fluctuates greatly with time, it is hardly affected by the fluctuation, and the reference point frequency is detected stably Thus, there is an effect that blurring or blurring of an image can be removed.
[0100]
In the fourth to sixth inventions, since the frequency resolution is improved by the super-resolution processing, the detection accuracy of the maximum point frequency is improved. In addition, for the frequency and amplitude waveforms after the segmented super-resolution processing, data is cut out based on the set threshold, and the center value of the frequency at all the maximal points is set as the reference point frequency by focusing on the maximal points of the cut out waveform. Since detection is performed, the amount of calculation can be reduced. Furthermore, even when the waveform of the frequency and amplitude is multi-peak and the position of the peak where the amplitude value is maximum fluctuates greatly with time, it is hardly affected by the fluctuation and the reference point frequency is detected stably. Thus, there is an effect that blurring and blurring of an image can be removed.
[0101]
In the seventh to ninth aspects, since the frequency resolution is improved by the super-resolution processing, the detection accuracy of the maximum point frequency is improved. In addition, for the frequency and amplitude waveforms after the segmented super-resolution processing, data is cut out based on the set threshold, and the minimum value of the frequency at all the maximum points is focused on the maximum point of the cut out waveform as a reference point frequency. Since detection is performed, the amount of calculation can be reduced. Furthermore, even when the waveform of the frequency and the amplitude is multi-peak and the position of the peak where the amplitude value is maximum fluctuates greatly with time, it is hardly affected by the fluctuation, and the reference point frequency is detected stably. Thus, there is an effect that blurring and blurring of an image can be removed.
[0102]
In the tenth to twelfth inventions, since the frequency resolution is improved by the super-resolution processing, the detection accuracy of the maximum point frequency is improved. In addition, for the frequency and amplitude waveforms after the segmented super-resolution processing, data is cut out based on the set threshold, and the maximum value of the frequency at all the maximum points is set as the reference point frequency by focusing on the local maximum points of the extracted waveform. Since detection is performed, the amount of calculation can be reduced. Furthermore, even when the waveform of the frequency and amplitude is multi-peak and the position of the peak where the amplitude value is maximum fluctuates greatly with time, it is hardly affected by the fluctuation and the reference point frequency is detected stably. Thus, there is an effect that blurring and blurring of an image can be removed.
[0103]
In the thirteenth to fifteenth aspects, the frequency resolution is improved by the super-resolution processing, so that the detection accuracy of the maximum point frequency is improved. Also, for the frequency and amplitude waveforms after the segmented super-resolution processing, data is cut out based on the set threshold, and the center value of the frequencies at all the maximal points is taken as the reference point frequency, focusing on the maximal points of the cut out waveform. Since detection is performed, the amount of calculation can be reduced. Furthermore, even when the waveform of the frequency and amplitude is multi-peak and the position of the peak where the amplitude value is maximum fluctuates greatly with time, it is hardly affected by the fluctuation and the reference point frequency is detected stably. Thus, there is an effect that blurring and blurring of an image can be removed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a phase correction unit according to Embodiment 1 of the present invention.
FIG. 2 is a configuration diagram of a phase correction unit according to the second embodiment of the present invention.
FIG. 3 is a configuration diagram of a phase correction unit according to the third embodiment of the present invention.
FIG. 4 is a configuration diagram of a phase correction unit according to a fourth embodiment of the present invention.
FIG. 5 is a configuration diagram of a phase correction unit according to the fifth embodiment of the present invention.
FIG. 6 is a diagram illustrating an operation of the segmented super-resolution processing circuit.
FIG. 7 is a diagram illustrating a method of detecting a maximum point frequency in a maximum point frequency detection circuit.
FIG. 8 is a diagram illustrating a method of detecting a reference point frequency in an average frequency detection circuit.
FIG. 9 is a diagram showing a method of detecting a reference point frequency in a center frequency detection circuit.
FIG. 10 is a diagram illustrating a method of detecting a reference point frequency in a minimum frequency detection circuit.
FIG. 11 is a diagram illustrating a method of detecting a reference point frequency in a maximum frequency detection circuit.
FIG. 12 is a diagram illustrating a method of detecting a reference point frequency in a center frequency detection circuit.
FIG. 13 is a configuration diagram of a radar signal processing device in the high-resolution radar device.
FIG. 14 is a configuration diagram of a conventional phase correction unit.
FIG. 15 is a diagram illustrating a processing method of a phase correction unit.
[Explanation of symbols]
1 data interface section, {2} pulse compression section, {3} distance correction section, {4 phase correction section, {5} frequency analysis section, {6} detection section, {7} display interface section, {8} buffer circuit, {9} division frequency analysis circuit, {10} maximum amplitude value detection Circuit, {11} smoothing circuit, {12} phase correction amount calculation circuit, {13} phase correction circuit, {14} division super-resolution processing circuit, {15} data cutout circuit, {16} threshold setting circuit, {17} maximum point frequency detection circuit, {18} average frequency detection circuit, 19 center frequency detection circuit, {20} minimum frequency detection circuit, {21} maximum frequency detection circuit, {22} center frequency detection circuit.

Claims (15)

Pulse compression means for pulse-compressing the target reception signal input from the radar device, distance correction means for correcting a distance shift due to time of the target reception signal pulse-compressed by the pulse compression means, and correction by the distance correction means. A phase correction means for correcting a phase shift of the target reception signal due to time, wherein the phase correction means corrects the target reception signal corrected by the distance correction means and the initial value of the radar and the target center of gravity. Storage means for storing a distance; segmented super-resolution processing means for super-resolution processing of a target reception signal at an initial distance between the radar output from the storage means and a target center of gravity in a small section in the time direction; Data cutout means for cutting out the frequency and amplitude waveforms obtained by the processing means based on a threshold, and the cutoff frequency and amplitude waves The maximum point frequency detecting means for detecting the maximum point for the frequency of the maximum point, the average value of the frequency detected by the maximum point frequency detecting means as a reference point frequency, A radar signal processing device comprising: The phase correction means includes: a smoothing means for smoothing a trajectory in the time direction of the reference point frequency detected by the average frequency detection means; and a phase from the trajectory in the time direction of the reference point frequency smoothed by the smoothing means. Phase correction amount calculating means for calculating a correction amount, and a phase correction circuit for correcting the phase of the target reception signal output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. The radar signal processing device according to claim 1, wherein: A buffer circuit for storing the target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity; a target reception at the initial distance between the radar output from the buffer circuit and the target center of gravity; A segmented super-resolution processing circuit that performs super-resolution processing on a signal in a small section in the time direction, a data cutout circuit that cuts out data on a frequency and amplitude waveform obtained by the above-described segmented superresolution processing circuit, A threshold setting circuit that sets a threshold necessary when extracting the data, a maximum point frequency detection circuit that detects a maximum point of the frequency and amplitude waveforms extracted by the data extraction circuit and calculates the frequency at that time, the maximum point An average frequency detection circuit that uses an average value of the frequencies detected by the frequency detection circuit as a reference point frequency; A smoothing circuit for smoothing the trajectory of the reference point frequency in the time direction detected by the circuit, and a phase correction amount calculating circuit for calculating a phase correction amount from the trajectory of the reference point frequency smoothed by the smoothing circuit in the time direction 2. The radar according to claim 1, further comprising a phase correction circuit for correcting the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit. Signal processing device. Pulse compression means for pulse-compressing the target reception signal input from the radar device, distance correction means for correcting a distance shift due to time of the target reception signal pulse-compressed by the pulse compression means, and correction by the distance correction means. A phase correction means for correcting a phase shift of the target reception signal due to time, wherein the phase correction means corrects the target reception signal corrected by the distance correction means and the initial value of the radar and the target center of gravity. Storage means for storing a distance; segmented super-resolution processing means for super-resolution processing of a target reception signal at an initial distance between the radar output from the storage means and a target center of gravity in a small section in the time direction; Data cutout means for cutting out the frequency and amplitude waveforms obtained by the processing means based on a threshold, and the cutoff frequency and amplitude waves A maximum point frequency detecting means for detecting a maximum point for the frequency of the maximum point, a center frequency detecting means having a center value of the frequency detected by the maximum point frequency detecting means as a reference point frequency. A radar signal processing device comprising: The phase correction means includes: a smoothing means for smoothing a trajectory in the time direction of the reference point frequency detected by the center frequency detection means; and a phase from the trajectory in the time direction of the reference point frequency smoothed by the smoothing means. Phase correction amount calculating means for calculating a correction amount, and a phase correction circuit for correcting the phase of the target reception signal output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. The radar signal processing device according to claim 4, wherein: A buffer circuit for storing the target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity; a target reception at the initial distance between the radar output from the buffer circuit and the target center of gravity; A segmented super-resolution processing circuit that performs super-resolution processing on a signal in a small section in the time direction, a data cutout circuit that cuts out data on a frequency and amplitude waveform obtained by the above-described segmented superresolution processing circuit, A threshold setting circuit that sets a threshold necessary when extracting the data, a maximum point frequency detection circuit that detects a maximum point of the frequency and amplitude waveforms extracted by the data extraction circuit and calculates the frequency at that time, the maximum point A center frequency detection circuit that uses the center value of the frequency detected by the frequency detection circuit as a reference point frequency; A smoothing circuit for smoothing the trajectory of the reference point frequency in the time direction detected by the circuit, and a phase correction amount calculating circuit for calculating a phase correction amount from the trajectory of the reference point frequency smoothed by the smoothing circuit in the time direction 5. The radar according to claim 4, further comprising: a phase correction circuit that corrects the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit. Signal processing device. Pulse compression means for pulse-compressing the target reception signal input from the radar device, distance correction means for correcting a distance shift due to time of the target reception signal pulse-compressed by the pulse compression means, and correction by the distance correction means. A phase correction means for correcting a phase shift of the target reception signal due to time, wherein the phase correction means corrects the target reception signal corrected by the distance correction means and the initial value of the radar and the target center of gravity. Storage means for storing a distance; segmented super-resolution processing means for super-resolution processing of a target reception signal at an initial distance between the radar output from the storage means and a target center of gravity in a small section in the time direction; Data cutout means for cutting out the frequency and amplitude waveforms obtained by the processing means based on a threshold, and the cutoff frequency and amplitude waves A maximum point frequency detecting means for detecting a maximum point for the frequency of the maximum point, a minimum frequency detecting means for setting a minimum value of the frequency detected by the maximum point frequency detecting means as a reference point frequency. A radar signal processing device comprising: The phase correction means includes: a smoothing means for smoothing a trajectory in the time direction of the reference point frequency detected by the minimum frequency detection means; and a phase from the trajectory in the time direction of the reference point frequency smoothed by the smoothing means. Phase correction amount calculating means for calculating a correction amount, and a phase correction circuit for correcting the phase of the target reception signal output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. The radar signal processing device according to claim 7, wherein: A buffer circuit for storing the target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity; a target reception at the initial distance between the radar output from the buffer circuit and the target center of gravity; A segmented super-resolution processing circuit that performs super-resolution processing on a signal in a small section in the time direction, a data cutout circuit that cuts out data on a frequency and amplitude waveform obtained by the above-described segmented superresolution processing circuit, A threshold setting circuit that sets a threshold necessary when extracting the data, a maximum point frequency detection circuit that detects a maximum point of the frequency and amplitude waveforms extracted by the data extraction circuit and calculates the frequency at that time, the maximum point A minimum frequency detection circuit that uses the minimum value of the frequency detected by the frequency detection circuit as a reference point frequency; A smoothing circuit for smoothing the trajectory of the reference point frequency in the time direction detected by the circuit, and a phase correction amount calculating circuit for calculating a phase correction amount from the trajectory of the reference point frequency smoothed by the smoothing circuit in the time direction 8. The radar according to claim 7, further comprising a phase correction circuit for correcting the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit. Signal processing device. Pulse compression means for pulse-compressing the target reception signal input from the radar device, distance correction means for correcting a distance shift due to time of the target reception signal pulse-compressed by the pulse compression means, and correction by the distance correction means. A phase correction means for correcting a phase shift of the target reception signal due to time, wherein the phase correction means corrects the target reception signal corrected by the distance correction means and the initial value of the radar and the target center of gravity. Storage means for storing a distance; segmented super-resolution processing means for super-resolution processing of a target reception signal at an initial distance between the radar output from the storage means and a target center of gravity in a small section in the time direction; Data cutout means for cutting out the frequency and amplitude waveforms obtained by the processing means based on a threshold, and the cutoff frequency and amplitude waves A maximum point frequency detection unit that detects a maximum point for the maximum point frequency to calculate the frequency of the maximum point, a maximum frequency detection unit that sets the maximum value of the frequency detected by the maximum point frequency detection unit as a reference point frequency. A radar signal processing device comprising: The phase correction means includes: a smoothing means for smoothing a trajectory in the time direction of the reference point frequency detected by the maximum frequency detection means; and a phase from the trajectory in the time direction of the reference point frequency smoothed by the smoothing means. Phase correction amount calculating means for calculating a correction amount, and a phase correction circuit for correcting the phase of the target reception signal output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. The radar signal processing device according to claim 10, wherein: A buffer circuit for storing the target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity; a target reception at the initial distance between the radar output from the buffer circuit and the target center of gravity; A segmented super-resolution processing circuit that performs super-resolution processing on a signal in a small section in the time direction, a data cutout circuit that cuts out data on a frequency and amplitude waveform obtained by the above-described segmented superresolution processing circuit, A threshold setting circuit that sets a threshold necessary when extracting the data, a maximum point frequency detection circuit that detects a maximum point of the frequency and amplitude waveforms extracted by the data extraction circuit and calculates the frequency at that time, the maximum point A maximum frequency detection circuit that uses the maximum value of the frequency detected by the frequency detection circuit as a reference point frequency; A smoothing circuit for smoothing the trajectory of the reference point frequency in the time direction detected by the circuit, and a phase correction amount calculating circuit for calculating a phase correction amount from the trajectory of the reference point frequency smoothed by the smoothing circuit in the time direction 11. The radar according to claim 10, further comprising: a phase correction circuit that corrects the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit. Signal processing device. Pulse compression means for pulse-compressing the target reception signal input from the radar device, distance correction means for correcting a distance shift due to time of the target reception signal pulse-compressed by the pulse compression means, and correction by the distance correction means. A phase correction means for correcting a phase shift of the target reception signal due to time, wherein the phase correction means corrects the target reception signal corrected by the distance correction means and the initial value of the radar and the target center of gravity. Storage means for storing a distance; segmented super-resolution processing means for super-resolution processing of a target reception signal at an initial distance between the radar output from the storage means and a target center of gravity in a small section in the time direction; Data cutout means for cutting out the frequency and amplitude waveforms obtained by the processing means based on a threshold, and the cutoff frequency and amplitude waves A maximum point frequency detecting means for detecting a point having a maximum value and calculating the frequency of the maximum point, a central frequency detecting means having a median value of the frequencies detected by the maximum point frequency detecting means as a reference point frequency. A radar signal processing device comprising: The phase correction means includes: a smoothing means for smoothing a trajectory in the time direction of the reference point frequency detected by the center frequency detection means; and a phase from the trajectory in the time direction of the reference point frequency smoothed by the smoothing means. Phase correction amount calculating means for calculating a correction amount, and a phase correction circuit for correcting the phase of the target reception signal output from the storage means using the phase correction amount calculated by the phase correction amount calculating means. 14. The radar signal processing device according to claim 13, wherein: A buffer circuit for storing the target reception signal corrected by the distance correction means and an initial distance between the radar and the target center of gravity; a target reception at the initial distance between the radar output from the buffer circuit and the target center of gravity; A segmented super-resolution processing circuit that performs super-resolution processing on a signal in a small section in the time direction, a data cutout circuit that cuts out data on a frequency and amplitude waveform obtained by the above-described segmented superresolution processing circuit, A threshold setting circuit that sets a threshold necessary when extracting the data, a maximum point frequency detection circuit that detects a maximum point of the frequency and amplitude waveforms extracted by the data extraction circuit and calculates the frequency at that time, the maximum point A center frequency detection circuit that uses a median value of the frequencies detected by the frequency detection circuit as a reference point frequency; A smoothing circuit for smoothing the trajectory of the reference point frequency in the time direction detected by the circuit, and a phase correction amount calculating circuit for calculating a phase correction amount from the trajectory of the reference point frequency smoothed by the smoothing circuit in the time direction 14. The radar according to claim 13, further comprising: a phase correction circuit that corrects the phase of the target reception signal output from the buffer circuit using the phase correction amount calculated by the phase correction amount calculation circuit. Signal processing device.

Images