JP2004170188A

JP2004170188A - Double polarization radar device and its signal processing method

Info

Publication number: JP2004170188A
Application number: JP2002335135A
Authority: JP
Inventors: Hisamichi Tanaka; 久理田中; Toshio Wakayama; 俊夫若山
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2002-11-19
Filing date: 2002-11-19
Publication date: 2004-06-17
Anticipated expiration: 2022-11-19
Also published as: JP3707469B2

Abstract

<P>PROBLEM TO BE SOLVED: To realize deflection correction for intensity ratio Zdr between polarizations obtained by double polarization observation, phase difference Φdp between polarizations and its distance differential Kdp. <P>SOLUTION: The double polarization radar device for measuring the value of double polarization from receiving wave received with horizontal polarization and vertical polarization has a first receiving part 006A for receiving the wave with horizontal polarization, a second receiving part 006B for receiving the wave with vertical polarization, a deflection sensor for measuring roll angle, pitch angle and yaw angle which represent the deflection of the radar device, a deflection correction processing part 009 for performing correction to remove the influence by the deflection from signal of the receiving wave of horizontal polarization from the first receiving part and the receiving wave of vertical polarization from the second receiving part by using shear angle of polarization calculated from the roll angle, the pitch angle and the yaw angle and a measured value calculation part 010 for calculating measured value of the double polarization from the corrected horizontal polarization receiving signal and corrected vertical polarization receiving signal. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
この発明は、気象レーダ装置、特に二重偏波レーダ装置及びその信号処理方法に関するものである。
【０００２】
【従来の技術】
従来から広く用いられている単一偏波の気象レーダでは、エコー強度と降雨強度の間に成立する関係式を用いて、降雨強度の推定を行っている。しかし、この関係式は雨滴の粒径分布によって大きく変化するため、単一偏波の気象レーダで正確な降雨強度を求めることは困難であった。
【０００３】
一般に雨滴は球を垂直方向に押し潰した回転楕円体に近い形状をしている。大きな粒径の雨滴は扁平度が大きく、小さな粒径の雨滴は扁平度が小さくほぼ球形となる。そのため、水平偏波と垂直偏波を用いた二重偏波レーダ観測を行えば、雨滴の形状に関する情報、すなわち粒径分布に対応する情報が得られるため、精度の高い降雨強度計測が可能になる。降雨領域を電波が通過する途中で生じる偏波間位相差に関する量であるＫｄｐは、降雨強度計測の精度向上に有効であると特に近年注目されている。二重偏波レーダによる気象観測については、例えば「非特許文献１」に一般的な説明がある。
【０００４】
図１０は従来からある二重偏波レーダの例である。この図において、００１は種信号発生部、００２は送信部、００３は分割部、００４Ａは第１の送受切替部（送受信切替部１）、００４Ｂは第２の送受切替部（送受切替部２）、００５は空中線、００６Ａは第１の受信部（受信部１）、００６Ｂは第２の受信部（受信部２）、００７は信号処理部、００８Ａは第１のＡＤ変換部（ＡＤ変換部１）、００８Ｂは第２のＡＤ変換部（ＡＤ変換部２）、０１０は計測値算出部である。
【０００５】
次に動作を説明する。種信号発生部００１では、レーダが空中に放射する送信波のもととなる種信号を発生する。この種信号は送信部００２にて加工され、その結果として送信波が送信部００２から出力される。具体的には、送信部００２にて種信号は大電力信号へと増幅される。送信部００２ではさらに必要に応じて送信波を変調する。通常は、レーダ観測における距離分解能を得るために、パルス変調が施される。
【０００６】
分割部００３では、送信部から出力された送信波を２分割し、それぞれ第１の送受信切替部００４Ａと第２の送受信切替部００４Ｂへと出力される。第１の送受信切替部００４Ａ及び第２の送受信切替部００４Ｂでは、レーダ装置の送信タイミングにおいては、分割部００３から出力された送信波を空中線００５へと伝送する。またレーダ装置の受信タイミングにおいては、空中線で受信された受信波をそれぞれ第１の受信部００６Ａ及び第２の受信部００６Ｂへと伝送する。
【０００７】
空中線００５は、第１の送受信切替部００４Ａから伝送される送信波と第２の送受信切替部００４Ｂから伝送される送信波の２つが入力される。空中線００５では、第１の送受信切替部００４Ａから伝送された送信波を水平偏波で大気中へ放射し、第２の送受信切替部００４Ｂから伝送された送信波を垂直偏波で大気中へ放射する。
【０００８】
大気で反射された反射電波は空中線００５で受信される。反射電波のうちの水平偏波成分は空中線００５から第１の送受切替部００４Ａを経て第１の受信部００６Ａへと伝送される。また、反射電波のうちの垂直偏波成分は空中線００５から第２の送受切替部００４Ｂを経て第２の受信部００６Ｂへと伝送される。第１の受信部００６Ａと第２の受信部００６Ｂは、それぞれ入力された水平偏波受信信号と垂直偏波受信信号に対して増幅及び周波数変換を施す。
【０００９】
第１の受信部００６Ａ及び第２の受信信号００６Ｂから出力される周波数変換後の受信信号は、信号処理部００７において信号処理が施される。信号処理部００７は第１のＡＤ変換部００８Ａ、第２のＡＤ変換部００８Ｂ、計測値算出部０１０から構成される。第１の受信部００６Ａから出力される周波数変換後の水平偏波受信信号は第１のＡＤ変換部００８Ａによってアナログ信号からディジタル信号へと変換される。変換された後の信号を以後は単に水平偏波受信信号と呼ぶことにする。また、第２の受信部００６Ｂから出力される周波数変換後の垂直偏波受信信号は第２のＡＤ変換部００８Ｂによってアナログ信号からディジタル信号へと変換される。変換された後の信号を以後は単に垂直偏波受信信号と呼ぶことにする。
【００１０】
二重偏波レーダで計測できる代表的な計測値として、偏波間強度比Ｚｄｒと偏波間位相差の距離微分Ｋｄｐがある。
【００１１】
Ｚｄｒは水平偏波で観測される受信電力と垂直偏波で観測される受信電力の比であり、次式によってレーダ観測データから算出される。
【００１２】
【数１】

【００１３】
【外１】

実際の信号処理では、信号のエルゴード性を仮定して、時間平均あるいは時間積分によって集合平均を実現する。すなわち、複数回のパルス送信により得られる信号を平均または積分する処理となる。この平均または積分に用いるデータ数をここでは積分数と呼ぶことにする。
【００１４】
Ｚｄｒが受信信号の強度に関する計測値であるのに対し、Ｋｄｐは受信信号の位相に関する計測値である。降雨領域では、水平偏波と垂直偏波とで電波伝播媒体の屈折率が異なるため、両偏波で伝播遅延の量が異なる。このことから、単位距離当たりで水平偏波と垂直偏波の位相がどれだけずれるかを表すＫｄｐの値から降雨強度を推定することが可能である。Ｋｄｐによる降雨強度推定は、レーダ反射因子による降雨強度推定よりも降雨粒径分布への依存性が小さい。そのため、Ｋｄｐ計測は降雨強度計測精度の改善に有効であると期待されている。
【００１５】
Ｋｄｐは、レーダ観測データから得られる水平偏波と垂直偏波の間の偏波間位相差φ_ｄｐを距離微分することにより得られる。
【００１６】
【数２】

【００１７】
【外２】

この位相差φ_ｄｐは、次式のように、水平偏波信号と垂直偏波信号の相互相関係数の位相を計算することにより得られる。
【００１８】
【数３】

【００１９】
なお、二重偏波レーダ装置の構成として、図１０では一つの送信部で発生された送信波を分割部で２分割し、水平偏波と垂直偏波を同時に送信するようなものとしているが、従来の二重偏波レーダ装置にはその他の構成を持つものもある。例えば、水平偏波と垂直偏波を同時に送信するのではなく、スイッチで両偏波を切り替えることにより、水平偏波と垂直偏波を交互に観測するものもある。
【００２０】
このような二重偏波レーダを船舶などの移動体上に搭載し、海洋上の気象観測を行う場合、船体の動揺によって偏波の方向が水平と垂直からずれるおそれがある。従来の船舶搭載気象レーダには、動揺修正装置として、船体動揺を打ち消す方向にレーダー空中線の方向を自動制御する装置を備えているが、この装置では空中線の偏波方向の補正まではできない。艦上で絶対水平面を保つ技術を採用することも考えられるが、気象レーダの数倍以上の費用となるため、この技術を利用することは現実的でない。
【００２１】
【非特許文献１】
「若山他、「気象レーダにおけるニ周波観測及び二重偏波観測の測定精度」、電子情報通信学会信学技報ＳＡＮＥ２０００−６」
【００２２】
この発明は上記のような問題点を解決するためになされたもので、二重偏波観測で得られる偏波間の強度比Ｚｄｒと偏波間位相差Φｄｐ及びその距離微分Ｋｄｐに対して、信号処理によって動揺補正を実現することを目的とする。
【００２３】
【課題を解決するための手段】
この発明の請求項１に係る二重偏波レーダ装置は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置において、水平偏波で受信波を受信する第１の受信部と、垂直偏波で受信波を受信する第２の受信部と、当該レーダ装置の動揺を表すロール角とピッチ角とヨー角を計測する動揺センサと、このロール角とピッチ角とヨー角から算出される偏波のずれ角を用い上記第１の受信部からの水平偏波の受信波及び第２の受信部からの垂直偏波の受信波の信号から上記動揺による影響を除去する補正をする動揺補正処理部と、この補正後の水平偏波受信信号及び垂直偏波受信信号から上記二重偏波の計測値を算出する計測値算出部とを備えたものである。
【００２４】
この発明の請求項２に係る二重偏波レーダ装置は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置において、水平偏波で受信波を受信する第１の受信部と、垂直偏波で受信波を受信する第２の受信部と、上記水平偏波受信信号及び垂直偏波受信信号から上記二重偏波の計測値を算出する計測値算出部と、当該レーダ装置の動揺を表すロール角とピッチ角とヨー角を計測する動揺センサと、このロール角とピッチ角とヨー角から算出される偏波のずれ角を用い上記二重偏波の計測値から上記動揺による影響を除去する補正をする動揺補正処理部とを備えたものである。
【００２５】
この発明の請求項３に係る二重偏波レーダ装置は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置において、水平偏波で受信波を受信する第１の受信部と、垂直偏波で受信波を受信する第２の受信部と、当該レーダ装置の動揺を表すロール角とピッチ角とヨー角を計測する動揺センサと、このロール角とピッチ角とヨー角から算出される偏波のずれ角と所定のずれ角しきい値との比較に基づき上記第１の受信部からの水平偏波の受信波及び第２の受信部からの垂直偏波の受信波の信号を選別し除去する動揺信号除去部と、この除去後の残りの水平偏波受信信号及び垂直偏波受信信号から上記二重偏波の計測値を算出する計測値算出部とを備えたものである。
【００２６】
この発明の請求項４に係る二重偏波レーダ装置は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置において、水平偏波で受信波を受信する第１の受信部と、垂直偏波で受信波を受信する第２の受信部と、上記水平偏波受信信号及び垂直偏波受信信号から上記二重偏波の計測値を算出する計測値算出部と、当該レーダ装置の動揺を表すロール角とピッチ角とヨー角を計測する動揺センサと、このロール角とピッチ角とヨー角から算出される偏波のずれ角と所定のずれ角しきい値との比較に基づき上記二重偏波の計測値を選別し除去する動揺信号除去部とを備えたものである。
【００２７】
この発明の請求項５に係る二重偏波レーダ装置の信号処理方法は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置において、次のステップを有するものである。
（１）１パルス分の水平偏波及び垂直偏波の受信信号を入力するステップ。
（２）当該レーダ装置の動揺を表すロール角とピッチ角とヨー角から偏波のずれ角を算出するステップ。
（３）この偏波のずれ角を用い上記１パルス分の水平偏波及び垂直偏波の受信信号に動揺補正を施すステップ。
（４）上記ステップ（１）から（３）の処理を複数パルス分繰り返すステップ。
（５）上記ステップ（４）の処理によりＮパルス分の受信信号を蓄積し、その蓄積データを用いて１時刻分の二重偏波の計測値を算出するステップ。
【００２８】
この発明の請求項６に係る二重偏波レーダ装置の信号処理方法は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置の信号処理方法において、次のステップを有するもの。
（１）１パルス分の水平偏波及び垂直偏波の受信信号を入力するステップ。
（２）当該レーダ装置の動揺を表すロール角とピッチ角とヨー角から偏波のずれ角を算出するステップ。
（３）上記ステップ（１）から（２）の処理を複数パルス分繰り返すステップ。
（４）上記ステップ（３）の処理によりＮパルス分の受信信号を蓄積し、その蓄積データを用いて１時刻分の二重偏波の計測値を算出するステップ。
（５）上記ステップ（３）の処理による偏波のずれ角を用い上記１時刻分の二重偏波の計測値に動揺補正を施すステップ。
【００２９】
この発明の請求項７に係る二重偏波レーダ装置の信号処理方法は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置の信号処理方法において、次のステップを有するもの。
（１）１パルス分の水平偏波及び垂直偏波の受信信号を入力するステップ。
（２）当該レーダ装置の動揺を表すロール角とピッチ角とヨー角から偏波のずれ角を算出するステップ。
（３）上記ステップ（１）から（２）の処理を複数パルス分繰り返すステップ。
（４）上記ステップ（３）の処理によりＮパルス分の受信信号を蓄積し、その蓄積データを用いて１時刻分の偏波間強度比並びに偏波間相互相関係数の大きさ及び位相を算出するステップ。
（５）上記算出した偏波間強度比、偏波間相互相関係数の大きさ又は位相のうち、少なくとも１種類の算出値に距離方向の平滑処理を行うステップ。
（６）上記ステップ（５）の処理で平滑処理が行われた偏波間強度比、偏波間相互相関係数の大きさ及び位相と、上記平滑処理が行われていないパラメータについては上記ステップ（４）の処理で算出した偏波間強度比、偏波間相互相関係数の大きさ及び位相とを組み合わせて用い、１時刻分の二重偏波の計測値を算出するステップ。
（７）上記ステップ（３）の処理による偏波のずれ角を用い上記１時刻分の二重偏波の計測値に動揺補正を施すステップ。
【００３０】
この発明の請求項８に係る二重偏波レーダ装置の信号処理方法は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置の信号処理方法において、次のステップを有するもの。
（１）１パルス分の水平偏波及び垂直偏波の受信信号を入力するステップ。
（２）当該レーダ装置の動揺を表すロール角とピッチ角とヨー角から偏波のずれ角を算出するステップ。
（３）この偏波のずれ角と所定のずれ角しきい値との比較に基づき上記水平偏波の受信波及び垂直偏波の受信波の信号を選別し除去するステップ。
（４）上記ステップ（１）から（３）の処理を複数パルス分繰り返すステップ。
（５）上記ステップ（４）の処理によりＮパルス分の受信信号を蓄積し、その蓄積データを用いて１時刻分の二重偏波の計測値を算出するステップ。
【００３１】
この発明の請求項９に係る二重偏波レーダ装置の信号処理方法は、水平偏波及び垂直偏波で受信した受信波から二重偏波の計測値を計測する二重偏波レーダ装置の信号処理方法において、次のステップを有するもの。
（１）１パルス分の水平偏波及び垂直偏波の受信信号を入力するステップ。
（２）当該レーダ装置の動揺を表すロール角とピッチ角とヨー角から偏波のずれ角を算出するステップ。
（３）上記ステップ（１）から（２）の処理を複数パルス分繰り返すステップ。
（４）上記ステップ（３）の処理によりＮパルス分の受信信号を蓄積し、その蓄積データを用いて１時刻分の二重偏波の計測値を算出するステップ。
（５）上記偏波のずれ角と所定のずれ角しきい値との比較に基づき上記１時刻分の二重偏波の計測値を選別し除去するステップ。
【００３２】
【発明の実施の形態】
実施の形態１．
図１はこの発明の二重偏波レーダ装置の構成を示すブロック図である。図において、００１は種信号発生部、００２は送信部、００３は分割部、００４Ａは第１の送受切替部（送受信切替部１）、００４Ｂは第２の送受切替部（送受切替部２）、００５は空中線、００６Ａは第１の受信部（受信部１）、００６Ｂは第２の受信部（受信部２）、００７は信号処理部、００８Ａは第１のＡＤ変換部（ＡＤ変換部１）、００８Ｂは第２のＡＤ変換部（ＡＤ変換部２）、００９は受信信号動揺補正処理部、０１０は計測値算出部である。
【００３３】
次に動作を説明する。種信号発生部００１では、レーダが空中に放射する送信波のもととなる種信号を発生する。この種信号は送信部００２にて加工され、その結果として送信波が送信部００２から出力される。具体的には、送信部００２にて種信号は大電力信号へと増幅される。送信部００２ではさらに必要に応じて送信波を変調する。通常は、レーダの距離分解能を得るために、パルス変調が施される。
【００３４】
分割部００３では、送信部から出力された送信波を２分割し、それぞれ第１の送受信切替部００４Ａと第２の送受信切替部００４Ｂへと出力される。第１の送受信切替部００４Ａ及び第２の送受信切替部００４Ｂでは、レーダ装置の送信タイミングにおいては、分割部００２から出力された送信波を空中線００５へと伝送する。またレーダ装置の受信タイミングにおいては、空中線で受信された受信波をそれぞれ第１の受信部００６Ａ及び第２の受信部００６Ｂへと伝送する。
【００３５】
空中線００５は、第１の送受信切替部００４Ａから伝送される送信波と第２の送受信切替部００４Ｂから伝送される送信波の２つが入力される。空中線００５では、第１の送受信切替部００４Ａから伝送された送信波を水平偏波で大気中へ放射し、第２の送受信切替部００４Ｂから伝送された送信波を水平偏波で大気中へ放射する。
【００３６】
大気で反射された反射電波は空中線００５で受信される。反射電波のうちの水平偏波成分は空中線００５から第１の送受切替部００４Ａを経て第１の受信部００６Ａへと伝送される。また、反射電波のうちの垂直偏波成分は空中線００５から第２の送受切替部００４Ｂを経て第２の受信部００６Ｂへと伝送される。第１の受信部００６Ａと第２の受信部００６Ｂは、それぞれ入力された水平偏波受信信号と垂直偏波受信信号に対して増幅及び周波数変換を施す。
【００３７】
第１の受信部００６Ａ及び第２の受信信号００６Ｂから出力される周波数変換後の受信信号は、信号処理部００７において信号処理が施される。信号処理部００７は第１のＡＤ変換部００８Ａ、第２のＡＤ変換部００８Ｂ、受信信号動揺補正処理部００９、計測値算出部０１０から構成される。第１の受信部００６Ａから出力される周波数変換後の水平偏波受信信号は第１のＡＤ変換部００８Ａによってアナログ信号からディジタル信号へと変換される。変換された後の信号を以後は単に水平偏波受信信号と呼ぶことにする。また、第２の受信部００６Ｂから出力される周波数変換後の垂直偏波受信信号は第２のＡＤ変換部００８Ｂによってアナログ信号からディジタル信号へと変換される。変換された後の信号を以後は単に垂直偏波受信信号と呼ぶことにする。
【００３８】
受信信号動揺補正処理部００９では、水平偏波受信信号と垂直偏波受信信号を入力する。さらに受信信号動揺補正処理部００９は動揺センサからロール角、ピッチ角、ヨー角の３成分から成る動揺センサデータを入力する。受信信号動揺補正処理部００９では、動揺センサデータをもとに水平偏波受信信号と垂直偏波受信信号に動揺補正を施し、動揺補正後水平偏波受信信号と動揺補正後垂直偏波受信信号を出力する。
【００３９】
なお、二重偏波レーダ装置の構成として、図１では一つの送信部で発生された送信波を分割部で２分割し、水平偏波と垂直偏波を同時に送信するようなものとしているが、従来の二重偏波レーダ装置にはその他の構成を持つものもある。例えば、水平偏波と垂直偏波を同時に送信するのではなく、スイッチで両偏波を切り替えることにより、水平偏波と垂直偏波を交互に観測するものもある。この場合にも、動揺補正を信号処理で行う原理は同様に適用することができる。
【００４０】
動揺補正の具体的な方法を以下に説明する。
【００４１】
まず動揺データから偏波方向のずれ角θ_ａを算出する手順を説明する。ロール角をθ_ｒ、ピッチ角をθ_ｐ、ヨー角をθ_ｙとする。動揺がない場合に空中線が水平偏波として放射する電波の偏波方向を単位ベクトルｅ_ｈとする。電波を放射する方位角をφとすると、ｅ_ｈは次式で表される。
【００４２】
【数４】

【００４３】
ロール角θ_ｒが、ピッチ角がθ_ｐ、ヨー角がθ_ｙの動揺がある場合に、空中線が水平偏波として放射する電波の偏波方向を単位ベクトルｅ_ｈｔとすると、ｅ_ｈｔは次式で表される。
【００４４】
【数５】

【００４５】
ここで、Ｒ_ｒ、Ｒ_ｐ、Ｒ_ｙはそれぞれ次の式で定義される回転行列である。
【００４６】
【数６】

【００４７】
【数７】

【００４８】
【数８】

【００４９】
水平面の単位法線ベクトルｎ_ｈは次式で表される。
【００５０】
【数９】

【００５１】
水平偏波の方向が水平面となす角、すなわち偏波方向のずれ角をθ_ａとする。θ_ａは次式で算出される。
【００５２】
【数１０】

【００５３】
次に受信信号に動揺補正を施す手順を説明する。
【００５４】
大気中の電波伝播及び後方散乱の効果を表す散乱行列Ｓを次式で定義する。
【００５５】
【数１１】

【００５６】
空中線から放射される直前の送信電界Ｅ_ｔは、空中線の水平偏波チャネルから放射される電界成分Ｅ_ｔ１と垂直偏波チャネルから放射される電界成分Ｅ_ｔ２を用いて次式で定義される。
【００５７】
【数１２】

【００５８】
また、空中線で受信された直後の受信電界Ｅ_ｒは、空中線の水平偏波チャネルで受信される電界成分Ｅ_ｒ１と垂直偏波チャネルで受信される電界成分Ｅ_ｒ２を用いて次式で定義される。
【００５９】
【数１３】

【００６０】
Ｅ_ｔとＥ_ｒの間には次式の関係がある。
【００６１】
【数１４】

【００６２】
ただし、Ｒ_ａ＋及びＲ_ａ−は偏波方向のずれ角θ_ａを用いて次式で定義される回転行列である。
【００６３】
【数１５】

【００６４】
【数１６】

【００６５】
以上から、次式によりＳ_ｈｈ、Ｓ_ｖｖを算出することができる。
【００６６】
【数１７】

【００６７】
【外３】

【００６８】
【数１８】

【００６９】
【外４】

【００７０】
【数１９】

【００７１】
ただし、＊は複素共役を表す。
【００７２】
計測値算出部０１０では、動揺補正後水平受信信号と動揺補正後垂直偏波受信信号を用いてＺｄｒやＫｄｐなどの計測値を算出する。計測値算出方法は従来の二重偏波レーダと同じ方法、すなわち数１、数２、数３を用いれば良い。
【００７３】
図２は以上の処理の流れをフロー図にしたものである。ステップｓｔ００１とステップｓｔ００５で囲まれたステップｓｔ００２〜ステップｓｔ００４の処理は積分数回だけ繰り返される。ステップｓｔ００２では１ヒット分、すなわち１送信パルスに対応する受信信号を入力する。ステップｓｔ００３では、ｓｔ００２で入力したデータを観測した時刻におけるロール、ピッチ、ヨーの動揺データから、偏波方向のずれの角度（偏波ずれ角）を算出する。ステップｓｔ００４では数１７により受信信号に対して動揺補正を行う。ステップｓｔ００６では、ステップｓｔ００１からステップｓｔ００５までの処理で得られた積分数分の受信信号を用いて、計測値を算出する。
【００７４】
なお、以上の説明では二重偏波レーダについて説明したが、本実施形態の動揺補正方法は気象観測用途に限らず、一般的な二重偏波レーダに適用できるものである。
【００７５】
以上のように、本発明の実施の形態１では、信号処理によって船舶の動揺を補正するため、レーダ装置自体の水平面を安定に保つ機構を用いずに、正確な二重偏波観測を行うことが可能である。
【００７６】
実施の形態２．
以上の実施形態１は、ＡＤ変換直後の受信信号に対して動揺補正の処理を行うものであるが、次に計測値を算出した後、すなわち積分処理を行った後のデータに対して動揺補正処理を行う実施形態を示す。図３は、本発明の実施の形態２の二重偏波レーダの構成を示す図である。この図において、１０９は計測値動揺補正処理部である。その他の符号は前述のものと同じである。
【００７７】
次に動作を説明する。本実施の形態における二重偏波レーダの動作は、第１のＡＤ変換部００８Ａ及び第２のＡＤ変換部００８Ｂによって、水平偏波及び垂直偏波の受信信号をディジタル化するところまでは、前述の実施の形態１の二重偏波レーダと同じ動作である。実施の形態１の二重偏波レーダではＡＤ変換直後の信号に動揺補正を行っていたが、本実施の形態の二重偏波レーダでは、動揺補正を行う前に、計測値算出部０１０によって計測値をまず算出する。計測値を算出する式は従来と同じ方法、すなわち数１、数２、数３を用いる。
【００７８】
ただし、動揺補正が行われていないため、計測値算出部０１０から出力される計測値は動揺による誤差が含まれている。そこで、計測値動揺補正処理部では、動揺補正前の受信信号から算出された計測値に対して、動揺補正を行う。
【００７９】
なお、二重偏波レーダ装置の構成として、図３では一つの送信部で発生された送信波を分割部で２分割し、水平偏波と垂直偏波を同時に送信するようなものとしているが、従来の二重偏波レーダ装置にはその他の構成を持つものもある。例えば、水平偏波と垂直偏波を同時に送信するのではなく、スイッチで両偏波を切り替えることにより、水平偏波と垂直偏波を交互に観測するものもある。この場合にも、動揺補正を信号処理で行う原理は同様に適用することができる。
【００８０】
動揺補正に用いる式を以下に示す。まず、数１７によりＳ_ｈｈは次式で表される。
【００８１】
【数２０】

【００８２】
ただし、Ａは次式で定義される。
【００８３】
【数２１】

【００８４】
【外５】

【００８５】
【数２２】

【００８６】
【数２３】

【００８７】
同様にして、数１７によりＳ_ｖｖは次式で表される。
【００８８】
【数２４】

【００８９】
ただし、Ｂは次式で定義される。
【００９０】
【数２５】

【００９１】
【外６】

【００９２】
【数２６】

【００９３】
ただし、Ｃ及びＤは次式で定義される。
【００９４】
【数２７】

【００９５】
【数２８】

【００９６】
【外７】

【００９７】
【数２９】

【００９８】
【外８】

【００９９】
【数３０】

【０１００】
図４は以上の処理の流れをフロー図にしたものである。ステップｓｔ１０１とステップｓｔ１０４で囲まれたｓｔ１０２〜ｓｔ１０３の処理は積分数回だけ繰り返される。ステップｓｔ１０２では１ヒット分の受信信号を入力する。ステップｓｔ１０３では、ｓｔ１０２で入力したデータを観測した時刻におけるロール、ピッチ、ヨーの動揺データから、偏波方向のずれの角度（偏波ずれ角）を算出する。
【０１０１】
ステップｓｔ１０１からステップｓｔ１０４までの処理によって、積分数分の受信信号が得られる。この積分数分のデータを用いて、ステップｓｔ１０５、ステップｓｔ１０６、ステップｓｔ１０７では、動揺による偏波のずれがないと仮定して、偏波間強度比Ｚ_ｄｒ、偏波間相互相関係数の大きさと位相の計測値を算出する。
【０１０２】
【外９】

ただし、集合平均は積分数分のデータを時間平均または時間積分することにより実現する。
【０１０３】
【外１０】

【０１０４】
なお、信号処理の途中で算出する補正前計測値の精度が不足する場合、距離方向に平滑化することによりランダムな誤差を低減することも有効である。図５はそのような処理を行う場合の処理の流れを示すフロー図である。この図において、ステップｓｔ２０１からステップｓｔ２０７の処理は図４のステップｓｔ１０１からステップｓｔ１０７の処理と同じであり、ステップｓｔ２０９からステップｓｔ２１４の処理は図４のステップｓｔ１０８からステップｓｔ１１３までの処理と同じである。図４と比較して図５の異なるのは、ステップｓｔ２０８が新たに挿入されたことである。ステップｓｔ２０８では各補正前計測値を距離方向に平滑化することにより、ランダムな誤差を低減するものである。
【０１０５】
以上のように、計測値算出後のデータに対しても、動揺補正により正しい計測値を得ることが可能である。計測値算出後ということは、すなわち積分後のデータに対して動揺補正を行うことを意味する。したがって、動揺補正の演算量は、受信信号に動揺補正を適用する場合に比べて少なくて済む。
【０１０６】
実施の形態３．
以上の実施形態では、信号処理によって動揺補正を行うものであるが、本実施の形態では、動揺量の小さい時間のデータのみを利用して信号処理を行うことにより、動揺による二重偏波計測値の誤差を低くするような二重偏波レーダ装置の形態について説明する。
【０１０７】
図６は本発明の実施の形態の二重偏波レーダの構成を示すブロック図である。この図において、２０９は大動揺受信信号除去部である。他の符号は前述のものと同じである。
【０１０８】
次に動作を説明する。
【０１０９】
動揺センサデータから偏波方向のずれ角θ_ａを算出する。算出されたθ_ａが予め設定したしきい値よりも大きくなる場合には、第１のＡＤ変換部００８Ａ及び第２のＡＤ変換部００８Ｂから出力されるデータを除去する。具体的には、受信信号の値に欠損値を入れるようにしても良いし、あるいは欠損であることを示す印をつけるようにしても良い。
【０１１０】
計測値算出部では、大動揺受信信号除去部２０９で除去されなかったデータのみを用いて計測値を算出する。動揺の状況によっては、大動揺受信信号除去部２０９におけるデータ除去により、十分な積分数が得られないこともある。そこで、予め設定した最低積分数よりも少ないデータ数しか積分できなかった場合には、その計測値を無効なものとするようにしても良い。
【０１１１】
なお、二重偏波レーダ装置の構成として、図６では一つの送信部で発生された送信波を分割部で２分割し、水平偏波と垂直偏波を同時に送信するようなものとしているが、従来の二重偏波レーダ装置にはその他の構成を持つものもある。例えば、水平偏波と垂直偏波を同時に送信するのではなく、スイッチで両偏波を切り替えることにより、水平偏波と垂直偏波を交互に観測するものもある。この場合にも、動揺補正を信号処理で行う原理は同様に適用することができる。
【０１１２】
図７は本発明の実施の形態の二重偏波レーダ装置の信号処理の流れを示すフロー図である。ステップｓｔ３０１からステップｓｔ３０６で囲まれたステップｓｔ３０２からｓｔ３０５までの処理は積分数回だけ繰り返される。ステップｓｔ３０２では１ヒット分の受信信号を入力する。ステップｓｔ３０３では、ｓｔ３０２で入力したデータを観測した時刻におけるロール、ピッチ、ヨーの動揺データから、偏波方向のずれの角度（偏波ずれ角）を算出する。
【０１１３】
ステップｓｔ３０４ではステップｓｔ３０３で算出した偏波ずれ角が予め設定した値を超えているか否かを判定する。もし超えている場合はステップｓｔ３０５へ進み、そうでない場合はｓｔ３０６へ進む。ステップｓｔ３０５では、偏波ずれ角が設定値を超える、すなわち動揺による観測誤差が大きくなると見なせる場合に、その時刻の受信信号を除去する。ステップｓｔ３０７では、ステップｓｔ３０５で除去されずに残ったデータを用いて計測値を算出する。
【０１１４】
本発明の実施形態によれば、動揺の小さい時間のデータのみを用いて計測値を算出するようにしているので、少ない演算量で誤差の少ない計測値を得ることができる。
【０１１５】
実施の形態４．
前述の実施の形態３では、動揺量の小さい時間のデータのみを利用して信号処理を行うことを考えた。動揺の周期がデータ積分時間に比べて十分に長い場合は、積分時間中の全データが動揺の大きい時間のデータとなるか、あるいは積分時間中の全データが動揺の小さい時間のデータとなるかのいずれかとなることがほとんどである。このことから本実施の形態では、動揺の周期が長い場合には計測値算出後にデータ除去の判定を行うようにする。
【０１１６】
図８は本発明の実施の形態の二重偏波レーダの構成を示すブロック図である。この図において、３０９は大動揺計測値除去部である。他の符号は前述のものと同じである。次に動作を説明する。
【０１１７】
動揺センサデータから偏波方向のずれ角θ_ａを算出する。算出されたθ_ａが予め設定したしきい値よりも大きくなる場合には、計測値算出部から出力されたデータを除去する。具体的には、計測値に欠損値を入れるようにしても良いし、あるいは欠損であることを示す印をつけるようにしても良い。
【０１１８】
動揺の大きさを評価する方法として、例えば積分開始時刻から積分終了時刻までの間に偏波ずれ角の絶対値が予め設定したしきい値を超えるか否かを判定することが考えられる。あるいは簡単には、積分時間中のある一時刻、例えば積分時間の区間の中央の時刻（平均時刻）の動揺量を判定するようにしても良い。
【０１１９】
なお、二重偏波レーダ装置の構成として、図８では一つの送信部で発生された送信波を分割部で２分割し、水平偏波と垂直偏波を同時に送信するようなものとしているが、従来の二重偏波レーダ装置にはその他の構成を持つものもある。例えば、水平偏波と垂直偏波を同時に送信するのではなく、スイッチで両偏波を切り替えることにより、水平偏波と垂直偏波を交互に観測するものもある。この場合にも、動揺補正を信号処理で行う原理は同様に適用することができる。
【０１２０】
図９は本発明の実施の形態の二重偏波レーダ装置の信号処理の流れを示すフロー図である。ステップｓｔ４０１からステップｓｔ４０４で囲まれたステップｓｔ４０２からｓｔ４０３までの処理は積分数回だけ繰り返される。ステップｓｔ４０２では１ヒット分の受信信号を入力する。ステップｓｔ４０３では、ｓｔ４０２で入力したデータを観測した時刻におけるロール、ピッチ、ヨーの動揺データから、偏波方向のずれの角度（偏波ずれ角）を算出し、その値を蓄積する。
【０１２１】
ステップｓｔ４０５では、ステップｓｔ４０２で入力した積分数分の受信信号を用いて計測値を計算する。ステップｓｔ４０６では、ｓｔ４０３で算出した積分数個の偏波ずれ角のうち、絶対値が最小となるものを抽出する。ステップｓｔ４０７では、ステップｓｔ４０６で抽出した偏波ずれ角の最小値がしきい値を超えるか否かを判定する。しきい値を超えた場合には、ステップｓｔ４０８にてその時刻の計測値を除去する。
【０１２２】
本発明の実施形態によれば、動揺の小さい時間の信号処理結果のみを残すようにするため、動揺による誤差の大きい計測値を出力することがない。
【０１２３】
【発明の効果】
以上のように、この発明の請求項１の二重偏波レーダ装置によれば、信号処理によって船舶の動揺を補正するため、レーダ装置自体の水平面を安定に保つ機構を用いずに、正確な二重偏波観測が可能となる。また、信号処理における積分処理前の受信信号に対して動揺補正を行うため、動揺補正の精度が高いという効果がある。
【０１２４】
また、この発明の請求項２の二重偏波レーダ装置によれば、積分処理後の計測値に対して動揺補正を行うため、動揺補正の演算量が少なくて済むという効果がある。
【０１２５】
また、この発明の請求項３の二重偏波レーダ装置によれば、動揺の小さい時間の受信信号のみを用いて計測値を算出するようにしているので、少ない演算量で誤差の少ない計測値を得ることができるという効果がある。
【０１２６】
また、この発明の請求項４の二重偏波レーダ装置によれば、動揺の小さい時間の信号処理結果のみを残すようにするため、動揺による誤差の大きい計測値を出力することがないという効果がある。
【０１２７】
また、この発明の請求項５のレーダ信号処理方法によれば、信号処理における積分処理前の受信信号に対して動揺補正を行うため、動揺補正の精度が高いという効果がある。
【０１２８】
また、この発明の請求項６のレーダ信号処理方法によれば、積分処理後の計測値に対して動揺補正を行うため、動揺補正の演算量が少なくて済むという効果がある。
【０１２９】
また、この発明の請求項７のレーダ信号処理方法によれば、信号処理の途中で距離方向に平滑化するため、動揺補正の精度が高くなるという効果がある。
【０１３０】
また、この発明の請求項８のレーダ信号処理方法によれば、動揺の小さい時間の受信信号のみを用いて計測値を算出するようにしているので、少ない演算量で誤差の少ない計測値を得ることができるという効果がある。
【０１３１】
また、この発明の請求項９のレーダ信号処理方法によれば、動揺の小さい時間の信号処理結果のみを残すようにするため、動揺による誤差の大きい計測値を出力することがないという効果がある。
【図面の簡単な説明】
【図１】この発明の実施の形態１の二重偏波レーダ装置の構成を示すブロック図。
【図２】この発明の実施の形態１の二重偏波レーダ信号処理方法の流れを示すフロー図。
【図３】この発明の実施の形態２のレーダ装置の構成を示すブロック図。
【図４】この発明の実施の形態２の二重偏波レーダ信号処理方法の流れを示すフロー図。
【図５】この発明の実施の形態２の二重偏波レーダ信号処理方法の別の流れを示すフロー図。
【図６】この発明の実施の形態３のレーダ装置の構成を示すブロック図。
【図７】この発明の実施の形態３の二重偏波レーダ信号処理方法の流れを示すフロー図。
【図８】この発明の実施の形態４のレーダ装置の構成を示すブロック図。
【図９】この発明の実施の形態４の二重偏波レーダ信号処理方法の流れを示すフロー図。
【図１０】従来のレーダ装置の構成例を示すブロック図。
【符号の説明】
００１種信号発生部、００２送信部、００３分割部、００４Ａ第１の送受切替部、００４Ｂ第２の送受切替部、００５空中線、００６Ａ第１の受信部、００６Ｂ第２の受信部、００７信号処理部、００８Ａ第１のＡＤ変換部、００８Ｂ第２のＡＤ変換部、００９受信信号動揺補正処理部、０１０計測値算出部、１０９計測値動揺補正処理部、２０９大動揺受信信号除去部、３０９大動揺計測値除去部。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a weather radar device, particularly to a dual polarization radar device and a signal processing method thereof.
[0002]
[Prior art]
In a single-polarization weather radar that has been widely used in the past, rainfall intensity is estimated using a relational expression established between the echo intensity and the rainfall intensity. However, since this relation greatly changes depending on the particle size distribution of raindrops, it has been difficult to obtain an accurate rainfall intensity with a single-polarization weather radar.
[0003]
Generally, raindrops have a shape similar to a spheroid obtained by crushing a sphere in the vertical direction. Raindrops with a large particle size have a large flatness, and raindrops with a small particle size have a small flatness and become almost spherical. Therefore, if dual-polarization radar observation using horizontal polarization and vertical polarization is performed, information on the shape of raindrops, that is, information corresponding to the particle size distribution, can be obtained, enabling highly accurate rainfall intensity measurement. Become. Recently, Kdp, which is a quantity related to the phase difference between polarizations generated while a radio wave passes through a rainfall region, has attracted attention in recent years as being effective for improving the accuracy of rainfall intensity measurement. A general description of meteorological observation by dual-polarization radar is given in, for example, "Non-Patent Document 1".
[0004]
FIG. 10 shows an example of a conventional dual polarization radar. In this figure, 001 is a seed signal generation unit, 002 is a transmission unit, 003 is a division unit, 004A is a first transmission / reception switching unit (transmission / reception switching unit 1), and 004B is a second transmission / reception switching unit (transmission / reception switching unit 2). , 005 are antennas, 006A is a first receiver (receiver 1), 006B is a second receiver (receiver 2), 007 is a signal processor, and 008A is a first AD converter (AD converter 1). ), 008B is a second AD conversion unit (AD conversion unit 2), and 010 is a measurement value calculation unit.
[0005]
Next, the operation will be described. The seed signal generator 001 generates a seed signal that is a source of a transmission wave radiated by the radar into the air. This kind of signal is processed by the transmission unit 002, and as a result, a transmission wave is output from the transmission unit 002. Specifically, the seed signal is amplified into a high power signal by the transmission unit 002. The transmission unit 002 further modulates the transmission wave as needed. Usually, pulse modulation is performed in order to obtain a distance resolution in radar observation.
[0006]
The division unit 003 divides the transmission wave output from the transmission unit into two, and outputs the two to the first transmission / reception switching unit 004A and the second transmission / reception switching unit 004B. The first transmission / reception switching unit 004A and the second transmission / reception switching unit 004B transmit the transmission wave output from the division unit 003 to the antenna 005 at the transmission timing of the radar device. Further, at the reception timing of the radar device, the reception wave transmitted through the antenna is transmitted to the first reception unit 006A and the second reception unit 006B, respectively.
[0007]
The antenna 005 receives two transmission waves, a transmission wave transmitted from the first transmission / reception switching unit 004A and a transmission wave transmitted from the second transmission / reception switching unit 004B. In the antenna 005, the transmission wave transmitted from the first transmission / reception switching unit 004A is radiated into the atmosphere with horizontal polarization, and the transmission wave transmitted from the second transmission / reception switching unit 004B is radiated into the atmosphere with vertical polarization. I do.
[0008]
The reflected radio wave reflected by the atmosphere is received by the antenna 005. The horizontal polarization component of the reflected radio wave is transmitted from the antenna 005 to the first reception unit 006A via the first transmission / reception switching unit 004A. The vertically polarized component of the reflected radio wave is transmitted from the antenna 005 to the second receiver 006B via the second transmission / reception switch 004B. The first receiving unit 006A and the second receiving unit 006B perform amplification and frequency conversion on the input horizontally polarized wave received signal and vertically polarized wave received signal, respectively.
[0009]
The frequency-converted reception signals output from the first reception unit 006A and the second reception signal 006B are subjected to signal processing in a signal processing unit 007. The signal processing unit 007 includes a first AD conversion unit 008A, a second AD conversion unit 008B, and a measurement value calculation unit 010. The frequency-converted horizontal polarization reception signal output from the first reception unit 006A is converted from an analog signal to a digital signal by the first AD conversion unit 008A. The signal after the conversion is hereinafter simply referred to as a horizontally polarized reception signal. Further, the frequency-converted vertical polarization reception signal output from the second reception unit 006B is converted from an analog signal to a digital signal by the second AD conversion unit 008B. The signal after the conversion is hereinafter simply referred to as a vertically polarized wave reception signal.
[0010]
Typical measurement values that can be measured by the dual-polarization radar include the inter-polarization intensity ratio Zdr and the distance derivative Kdp of the inter-polarization phase difference.
[0011]
Zdr is the ratio of the received power observed with horizontal polarization to the received power observed with vertical polarization, and is calculated from radar observation data by the following equation.
[0012]
(Equation 1)

[0013]
[Outside 1]

In actual signal processing, assuming the ergodicity of a signal, a collective average is realized by time average or time integration. That is, it is a process of averaging or integrating signals obtained by multiple pulse transmissions. The number of data used for the averaging or integration is referred to as an integral number here.
[0014]
While Zdr is a measurement related to the strength of the received signal, Kdp is a measurement related to the phase of the received signal. In the rainfall region, since the refractive index of the radio wave propagation medium is different between the horizontally polarized wave and the vertically polarized wave, the amount of propagation delay is different between both polarized waves. From this, it is possible to estimate the rainfall intensity from the value of Kdp, which indicates how much the phase of the horizontal polarization and the phase of the vertical polarization are shifted per unit distance. Rainfall intensity estimation by Kdp has less dependence on the rainfall particle size distribution than rainfall intensity estimation by the radar reflection factor. Therefore, Kdp measurement is expected to be effective for improving the rainfall intensity measurement accuracy.
[0015]
Kdp is a phase difference φ between horizontal and vertical polarizations obtained from radar observation data. _dp Is obtained by performing distance differentiation on
[0016]
(Equation 2)

[0017]
[Outside 2]

This phase difference φ _dp Is obtained by calculating the phase of the cross-correlation coefficient between the horizontal polarization signal and the vertical polarization signal as in the following equation.
[0018]
[Equation 3]

[0019]
As a configuration of the dual polarization radar apparatus, in FIG. 10, the transmission wave generated by one transmission unit is divided into two by the division unit, and the horizontal polarization and the vertical polarization are simultaneously transmitted. Some conventional dual polarization radar apparatuses have other configurations. For example, there is a method in which horizontal polarization and vertical polarization are observed alternately by switching both polarizations with a switch instead of transmitting horizontal polarization and vertical polarization simultaneously.
[0020]
When such a dual-polarization radar is mounted on a moving body such as a ship to perform weather observation on the sea, the direction of polarization may be shifted from horizontal to vertical due to the fluctuation of the hull. Conventional marine weather radars are equipped with a device for automatically controlling the direction of the radar antenna in a direction to cancel the hull as a motion correction device, but this device cannot correct the polarization direction of the antenna. It is conceivable to adopt a technology that maintains an absolute horizontal plane on a ship, but it is not practical to use this technology because it costs several times more than weather radar.
[0021]
[Non-patent document 1]
"Wakayama et al.," Measurement Accuracy of Dual-Frequency Observation and Dual-Polarization Observation in Weather Radar ", IEICE Technical Report SANE2000-6"
[0022]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a signal processing is performed on an intensity ratio Zdr between polarizations obtained by dual polarization observation, a phase difference Φdp between polarizations, and a distance derivative Kdp thereof. The purpose of the present invention is to realize the sway correction.
[0023]
[Means for Solving the Problems]
A dual-polarization radar apparatus according to claim 1 of the present invention is a dual-polarization radar apparatus that measures a double-polarization measurement value from a received wave received with horizontal polarization and vertical polarization. A first receiving unit for receiving a received wave at a second receiving unit, a second receiving unit for receiving a received wave with a vertically polarized wave, and a sway sensor for measuring a roll angle, a pitch angle, and a yaw angle representing sway of the radar device The polarization shift angle calculated from the roll angle, the pitch angle, and the yaw angle is used to calculate the horizontal polarization reception wave from the first reception unit and the vertical polarization reception wave from the second reception unit. A fluctuation correction processing unit that performs correction to remove the influence of the fluctuation from the signal, and a measurement value calculation unit that calculates the measurement value of the double polarization from the horizontal polarization reception signal and the vertical polarization reception signal after the correction. It is provided with.
[0024]
A dual-polarization radar device according to claim 2 of the present invention is a dual-polarization radar device for measuring a measured value of double polarization from a received wave received with horizontal polarization and vertical polarization. A first receiving unit for receiving a received wave with a second polarized wave; a second receiving unit for receiving a received wave with a vertically polarized wave; and a measurement value of the double polarization from the horizontal polarized wave received signal and the vertical polarized wave received signal. And a fluctuation sensor that measures a roll angle, a pitch angle, and a yaw angle representing the fluctuation of the radar device, and a deviation angle of the polarization calculated from the roll angle, the pitch angle, and the yaw angle. And a fluctuation correction processing unit that corrects the influence of the fluctuation from the measured value of the dual polarization.
[0025]
A dual-polarization radar device according to claim 3 of the present invention is a dual-polarization radar device that measures a double-polarization measurement value from a received wave received with horizontal polarization and vertical polarization. A first receiving unit for receiving a received wave at a first receiving unit, a second receiving unit for receiving a received wave at a vertically polarized wave, and a sway sensor for measuring a roll angle, a pitch angle, and a yaw angle representing the sway of the radar device. Based on a comparison between the deviation angle of the polarization calculated from the roll angle, the pitch angle, and the yaw angle and a predetermined deviation angle threshold value, the reception wave of the horizontal polarization from the first receiver and the second A perturbation signal removal unit that selects and removes a vertically polarized reception wave signal from the reception unit, and calculates the double polarization measurement value from the remaining horizontal polarization reception signal and vertical polarization reception signal after the removal. And a measurement value calculation unit for calculating.
[0026]
A dual-polarization radar device according to claim 4 of the present invention is a dual-polarization radar device that measures a double-polarization measurement value from a received wave received with horizontal polarization and vertical polarization. A first receiving unit for receiving a received wave with a second polarized wave; a second receiving unit for receiving a received wave with a vertically polarized wave; and a measurement value of the double polarization from the horizontal polarized wave received signal and the vertical polarized wave received signal. And a fluctuation sensor that measures a roll angle, a pitch angle, and a yaw angle representing the fluctuation of the radar device, and a deviation angle of the polarization calculated from the roll angle, the pitch angle, and the yaw angle. A fluctuation signal removing section for selecting and removing the measured value of the double polarization based on comparison with a predetermined shift angle threshold value.
[0027]
A signal processing method for a dual-polarization radar device according to claim 5 of the present invention is directed to a dual-polarization radar device that measures a double-polarization measurement value from a reception wave received with horizontal polarization and vertical polarization. Has the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) a step of performing a wobble correction on the received signal of one pulse of the horizontal polarization and the vertical polarization using the deviation angle of the polarization.
(4) A step of repeating the processing of steps (1) to (3) for a plurality of pulses.
(5) A step of accumulating the received signals for N pulses by the processing of the step (4) and calculating the measured value of the double polarization for one time using the accumulated data.
[0028]
A signal processing method for a dual-polarization radar device according to claim 6 of the present invention is directed to a dual-polarization radar device that measures a double-polarization measurement value from a received wave received with horizontal polarization and vertical polarization. A signal processing method having the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) A step of repeating the processing of steps (1) and (2) for a plurality of pulses.
(4) A step of accumulating the received signals for N pulses by the processing of the step (3), and calculating the measured value of the double polarization for one time using the accumulated data.
(5) a step of performing a wobble correction on the measured value of the double polarization for the one time using the deviation angle of the polarization by the processing of the step (3).
[0029]
A signal processing method for a dual-polarization radar device according to claim 7 of the present invention is directed to a dual-polarization radar device that measures a double-polarization measurement value from a received wave received with horizontal polarization and vertical polarization. A signal processing method having the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) A step of repeating the processing of steps (1) and (2) for a plurality of pulses.
(4) The received signals of N pulses are accumulated by the processing of the above step (3), and the magnitude and phase of the inter-polarization intensity ratio and the inter-polarization cross-correlation coefficient for one time are calculated using the accumulated data. Step.
(5) A step of performing a distance direction smoothing process on at least one of the calculated values of the intensity ratio between polarizations and the magnitude or phase of the cross-correlation coefficient between polarizations.
(6) The inter-polarization intensity ratio, the magnitude and the phase of the cross-polarization cross-correlation coefficient on which the smoothing processing has been performed in the processing of the step (5), and the parameter on which the smoothing processing has not been performed are described in the step (4). B) calculating the double-polarized wave measurement value for one time using the combination of the polarization intensity ratio, the magnitude of the cross-polarization cross-correlation coefficient, and the phase calculated in the processing of the above).
(7) a step of performing a wobble correction on the measured value of the double polarization for the one time using the deviation angle of the polarization by the processing of the step (3).
[0030]
A signal processing method for a dual-polarization radar device according to claim 8 of the present invention is directed to a dual-polarization radar device that measures a measured value of double polarization from a received wave received with horizontal polarization and vertical polarization. A signal processing method having the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) a step of selecting and removing the signals of the horizontally polarized reception wave and the vertically polarized reception wave based on a comparison between the deviation angle of the polarization and a predetermined deviation angle threshold value.
(4) A step of repeating the processing of steps (1) to (3) for a plurality of pulses.
(5) A step of accumulating the received signals for N pulses by the processing of the step (4) and calculating the measured value of the double polarization for one time using the accumulated data.
[0031]
According to a ninth aspect of the present invention, there is provided a signal processing method for a dual-polarization radar device, wherein the dual-polarization radar device measures a double-polarization measurement value from a received wave received with a horizontal polarization and a vertical polarization. A signal processing method having the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) A step of repeating the processing of steps (1) and (2) for a plurality of pulses.
(4) A step of accumulating the received signals for N pulses by the processing of the step (3), and calculating the measured value of the double polarization for one time using the accumulated data.
(5) a step of selecting and removing the measured value of the double polarization for the one time based on the comparison between the polarization shift angle and a predetermined shift angle threshold value.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a dual polarization radar apparatus according to the present invention. In the figure, 001 is a seed signal generation unit, 002 is a transmission unit, 003 is a division unit, 004A is a first transmission / reception switching unit (transmission / reception switching unit 1), 004B is a second transmission / reception switching unit (transmission / reception switching unit 2), 005 is an antenna, 006A is a first receiver (receiver 1), 006B is a second receiver (receiver 2), 007 is a signal processor, and 008A is a first AD converter (AD converter 1). 008B is a second AD conversion unit (AD conversion unit 2), 009 is a received signal fluctuation correction processing unit, and 010 is a measurement value calculation unit.
[0033]
Next, the operation will be described. The seed signal generator 001 generates a seed signal that is a source of a transmission wave radiated by the radar into the air. This kind of signal is processed by the transmission unit 002, and as a result, a transmission wave is output from the transmission unit 002. Specifically, the seed signal is amplified into a high power signal by the transmission unit 002. The transmission unit 002 further modulates the transmission wave as needed. Usually, pulse modulation is performed in order to obtain radar range resolution.
[0034]
The division unit 003 divides the transmission wave output from the transmission unit into two, and outputs the two to the first transmission / reception switching unit 004A and the second transmission / reception switching unit 004B. The first transmission / reception switching unit 004A and the second transmission / reception switching unit 004B transmit the transmission wave output from the division unit 002 to the antenna 005 at the transmission timing of the radar device. Further, at the reception timing of the radar device, the reception wave transmitted through the antenna is transmitted to the first reception unit 006A and the second reception unit 006B, respectively.
[0035]
The antenna 005 receives two transmission waves, a transmission wave transmitted from the first transmission / reception switching unit 004A and a transmission wave transmitted from the second transmission / reception switching unit 004B. In the antenna 005, the transmission wave transmitted from the first transmission / reception switching unit 004A is radiated into the atmosphere with horizontal polarization, and the transmission wave transmitted from the second transmission / reception switching unit 004B is radiated into the atmosphere with horizontal polarization. I do.
[0036]
The reflected radio wave reflected by the atmosphere is received by the antenna 005. The horizontal polarization component of the reflected radio wave is transmitted from the antenna 005 to the first reception unit 006A via the first transmission / reception switching unit 004A. The vertically polarized component of the reflected radio wave is transmitted from the antenna 005 to the second receiver 006B via the second transmission / reception switch 004B. The first receiving unit 006A and the second receiving unit 006B perform amplification and frequency conversion on the input horizontally polarized wave received signal and vertically polarized wave received signal, respectively.
[0037]
The frequency-converted reception signals output from the first reception unit 006A and the second reception signal 006B are subjected to signal processing in a signal processing unit 007. The signal processing unit 007 includes a first AD conversion unit 008A, a second AD conversion unit 008B, a received signal fluctuation correction processing unit 009, and a measurement value calculation unit 010. The frequency-converted horizontal polarization reception signal output from the first reception unit 006A is converted from an analog signal to a digital signal by the first AD conversion unit 008A. The signal after the conversion is hereinafter simply referred to as a horizontally polarized reception signal. Further, the frequency-converted vertical polarization reception signal output from the second reception unit 006B is converted from an analog signal to a digital signal by the second AD conversion unit 008B. The signal after the conversion is hereinafter simply referred to as a vertically polarized wave reception signal.
[0038]
The received signal fluctuation correction processing unit 009 receives the horizontally polarized wave received signal and the vertically polarized wave received signal. Further, the received signal fluctuation correction processing unit 009 inputs the fluctuation sensor data including the three components of the roll angle, the pitch angle, and the yaw angle from the fluctuation sensor. The received signal fluctuation correction processing unit 009 performs the fluctuation correction on the horizontal polarization reception signal and the vertical polarization reception signal based on the fluctuation sensor data, and corrects the horizontal polarization reception signal after the fluctuation correction and the vertical polarization reception signal after the fluctuation correction. Is output.
[0039]
In FIG. 1, the configuration of the dual polarization radar device is such that the transmission wave generated by one transmission unit is divided into two by the division unit, and the horizontal polarization and the vertical polarization are simultaneously transmitted. Some conventional dual polarization radar apparatuses have other configurations. For example, there is a method in which horizontal polarization and vertical polarization are observed alternately by switching both polarizations with a switch instead of transmitting horizontal polarization and vertical polarization simultaneously. Also in this case, the principle of performing the sway correction by signal processing can be similarly applied.
[0040]
A specific method of the motion compensation will be described below.
[0041]
First, the deviation angle θ in the polarization direction from the oscillation data _a The procedure for calculating is described. Roll angle θ _r , Pitch angle θ _p And yaw angle θ _y And The unit vector e is the polarization direction of the radio wave radiated by the antenna as horizontal polarization when there is no fluctuation. _h And Assuming that the azimuth for radiating radio waves is φ, e _h Is represented by the following equation.
[0042]
(Equation 4)

[0043]
Roll angle θ _r But the pitch angle is θ _p , The yaw angle is θ _y When the antenna oscillates, the polarization direction of radio waves radiated from the antenna as horizontal polarization is represented by the unit vector e. _ht Then e _ht Is represented by the following equation.
[0044]
(Equation 5)

[0045]
Where R _r , R _p , R _y Is a rotation matrix defined by the following equations.
[0046]
(Equation 6)

[0047]
(Equation 7)

[0048]
(Equation 8)

[0049]
Horizontal unit normal vector n _h Is represented by the following equation.
[0050]
(Equation 9)

[0051]
The angle between the horizontal polarization direction and the horizontal plane, that is, the deviation angle in the polarization direction is θ _a And θ _a Is calculated by the following equation.
[0052]
(Equation 10)

[0053]
Next, a procedure for performing the fluctuation correction on the received signal will be described.
[0054]
A scattering matrix S representing the effects of radio wave propagation and backscattering in the atmosphere is defined by the following equation.
[0055]
[Equation 11]

[0056]
Transmission electric field E just before emission from the antenna _t Is the electric field component E radiated from the antenna's horizontal polarization channel. _t1 And the electric field component E radiated from the vertical polarization channel _t2 Is defined by the following equation.
[0057]
(Equation 12)

[0058]
In addition, the reception electric field E immediately after reception by the antenna _r Is the electric field component E received on the antenna's horizontal polarization channel. _r1 And the electric field component E received in the vertical polarization channel _r2 Is defined by the following equation.
[0059]
(Equation 13)

[0060]
E _t And E _r Has the following relationship:
[0061]
[Equation 14]

[0062]
Where R _{a +} And R _a- Is the deviation angle θ in the polarization direction _a Is a rotation matrix defined by the following equation.
[0063]
[Equation 15]

[0064]
(Equation 16)

[0065]
From the above, S _hh , S _vv Can be calculated.
[0066]
[Equation 17]

[0067]
[Outside 3]

[0068]
(Equation 18)

[0069]
[Outside 4]

[0070]
[Equation 19]

[0071]
Here, * represents a complex conjugate.
[0072]
The measurement value calculation unit 010 calculates measurement values such as Zdr and Kdp using the horizontal correction signal after the vibration correction and the vertical polarization reception signal after the vibration correction. The measurement value calculation method may be the same as that of the conventional dual-polarization radar, that is, Equations 1, 2, and 3 may be used.
[0073]
FIG. 2 is a flowchart showing the above processing flow. The processing of steps st002 to st004 surrounded by steps st001 and st005 is repeated several times for integration. In step st002, a reception signal corresponding to one hit, that is, one transmission pulse is input. In step st003, the angle of deviation in the polarization direction (polarization deviation angle) is calculated from the roll, pitch, and yaw fluctuation data at the time when the data input in st002 is observed. In step st004, the motion compensation is performed on the received signal according to Expression 17. In step st006, a measurement value is calculated using the received signals for the integral number obtained in the processing from step st001 to step st005.
[0074]
In the above description, the dual polarization radar has been described. However, the fluctuation correction method according to the present embodiment is not limited to the application for weather observation, but can be applied to a general dual polarization radar.
[0075]
As described above, in the first embodiment of the present invention, accurate double-polarization observation is performed without using a mechanism for stably maintaining the horizontal plane of the radar device itself in order to correct the motion of the ship by signal processing. Is possible.
[0076]
Embodiment 2 FIG.
In the above-described first embodiment, the motion compensation processing is performed on the received signal immediately after the AD conversion. 2 shows an embodiment for performing processing. FIG. 3 is a diagram showing a configuration of the dual polarization radar according to the second embodiment of the present invention. In this figure, reference numeral 109 denotes a measured value fluctuation correction processing unit. Other symbols are the same as those described above.
[0077]
Next, the operation will be described. The operation of the dual-polarization radar according to the present embodiment is the same as that described above until the first AD converter 008A and the second AD converter 008B digitize the horizontally polarized and vertically polarized received signals. This is the same operation as the dual polarization radar of the first embodiment. In the dual polarization radar according to the first embodiment, the fluctuation correction is performed on the signal immediately after the AD conversion. However, in the dual polarization radar according to the present embodiment, before performing the fluctuation correction, the measurement value calculation unit 010 performs the correction. First, the measured value is calculated. The formula for calculating the measured value uses the same method as that of the related art, that is, Formula 1, Formula 2, and Formula 3.
[0078]
However, since the sway correction has not been performed, the measurement value output from the measurement value calculation unit 010 includes an error due to sway. Therefore, the measured value fluctuation correction processing unit performs the fluctuation correction on the measured value calculated from the received signal before the fluctuation correction.
[0079]
In FIG. 3, the configuration of the dual polarization radar apparatus is such that the transmission wave generated by one transmission unit is divided into two by the division unit, and the horizontal polarization and the vertical polarization are transmitted simultaneously. Some conventional dual polarization radar apparatuses have other configurations. For example, there is a method in which horizontal polarization and vertical polarization are observed alternately by switching both polarizations with a switch instead of transmitting horizontal polarization and vertical polarization simultaneously. Also in this case, the principle of performing the sway correction by signal processing can be similarly applied.
[0080]
The equation used for the motion compensation is shown below. First, S _hh Is represented by the following equation.
[0081]
(Equation 20)

[0082]
Here, A is defined by the following equation.
[0083]
(Equation 21)

[0084]
[Outside 5]

[0085]
(Equation 22)

[0086]
[Equation 23]

[0087]
Similarly, S _vv Is represented by the following equation.
[0088]
(Equation 24)

[0089]
Here, B is defined by the following equation.
[0090]
(Equation 25)

[0091]
[Outside 6]

[0092]
(Equation 26)

[0093]
Here, C and D are defined by the following equations.
[0094]
[Equation 27]

[0095]
[Equation 28]

[0096]
[Outside 7]

[0097]
(Equation 29)

[0098]
[Outside 8]

[0099]
[Equation 30]

[0100]
FIG. 4 is a flowchart showing the above processing flow. The processing of st102 to st103 surrounded by step st101 and step st104 is repeated several times for integration. In step st102, a received signal for one hit is input. In step st103, the angle of deviation in the polarization direction (polarization deviation angle) is calculated from the roll, pitch, and yaw fluctuation data at the time when the data input in st102 is observed.
[0101]
By the processing from step st101 to step st104, received signals for the integral number are obtained. Using the data of this integration number, in step st105, step st106, and step st107, the polarization intensity ratio Z _dr , And the magnitude and phase of the polarization cross-correlation coefficient are measured.
[0102]
[Outside 9]

However, collective averaging is realized by time-averaging or time-integrating data for the number of integrations.
[0103]
[Outside 10]

[0104]
If the accuracy of the pre-correction measurement value calculated during signal processing is insufficient, it is also effective to reduce random errors by smoothing in the distance direction. FIG. 5 is a flowchart showing the flow of the processing when such processing is performed. In this figure, the processing from step st201 to step st207 is the same as the processing from step st101 to step st107 in FIG. 4, and the processing from step st209 to step st214 is the same as the processing from step st108 to step st113 in FIG. . 5 is different from FIG. 4 in that step st208 is newly inserted. In step st208, random errors are reduced by smoothing the measured values before correction in the distance direction.
[0105]
As described above, it is possible to obtain a correct measurement value for the data for which the measurement value has been calculated by performing the shake correction. After the calculation of the measured value means that the motion compensation is performed on the data after the integration. Therefore, the calculation amount of the motion compensation is smaller than the case where the motion compensation is applied to the received signal.
[0106]
Embodiment 3 FIG.
In the above embodiment, the fluctuation correction is performed by the signal processing. However, in the present embodiment, the signal processing is performed using only the data of the time when the fluctuation amount is small, so that the double polarization measurement by the fluctuation is performed. An embodiment of a dual-polarization radar device that reduces the value error will be described.
[0107]
FIG. 6 is a block diagram showing a configuration of the dual polarization radar according to the embodiment of the present invention. In this figure, reference numeral 209 denotes a large fluctuation received signal removing unit. Other symbols are the same as those described above.
[0108]
Next, the operation will be described.
[0109]
The deviation angle θ in the polarization direction from the motion sensor data _a Is calculated. Calculated θ _a Is larger than a preset threshold, the data output from the first AD converter 008A and the second AD converter 008B are removed. Specifically, a missing value may be added to the value of the received signal, or a mark indicating that the value is missing may be added.
[0110]
The measurement value calculation unit calculates the measurement value using only the data that has not been removed by the large sway reception signal removal unit 209. Depending on the situation of the sway, a sufficient integration number may not be obtained due to the data removal in the large sway reception signal removal unit 209. Therefore, when only the number of data smaller than the preset minimum integration number can be integrated, the measured value may be invalidated.
[0111]
In FIG. 6, the configuration of the dual polarization radar apparatus is such that the transmission wave generated by one transmission unit is divided into two by the division unit, and the horizontal polarization and the vertical polarization are simultaneously transmitted. Some conventional dual polarization radar devices have other configurations. For example, there is a method in which horizontal polarization and vertical polarization are observed alternately by switching both polarizations with a switch instead of transmitting horizontal polarization and vertical polarization simultaneously. Also in this case, the principle of performing the sway correction by signal processing can be similarly applied.
[0112]
FIG. 7 is a flowchart showing the flow of signal processing of the dual polarization radar device according to the embodiment of the present invention. The processes from steps st302 to st305 surrounded by steps st301 to st306 are repeated several times for integration. In step st302, a received signal for one hit is input. In step st303, the angle of polarization shift (polarization shift angle) is calculated from the roll, pitch, and yaw fluctuation data at the time when the data input in st302 is observed.
[0113]
In step st304, it is determined whether or not the polarization shift angle calculated in step st303 exceeds a preset value. If it exceeds, go to step st305, otherwise go to st306. In step st305, when the polarization shift angle exceeds the set value, that is, when it can be considered that the observation error due to the fluctuation increases, the received signal at that time is removed. In step st307, a measurement value is calculated using the data that has not been removed in step st305.
[0114]
According to the embodiment of the present invention, since the measurement value is calculated using only the data of the time during which the fluctuation is small, it is possible to obtain a measurement value with a small amount of calculation and a small error.
[0115]
Embodiment 4 FIG.
In the above-described third embodiment, it has been considered that signal processing is performed using only data of a time during which the amount of fluctuation is small. If the oscillation period is sufficiently long compared to the data integration time, will all the data during the integration time be data during the large oscillation time, or will all data during the integration time be the data during the small oscillation time In most cases it will be one of For this reason, in the present embodiment, when the period of the oscillation is long, the determination of the data removal is made after the measurement value is calculated.
[0116]
FIG. 8 is a block diagram showing the configuration of the dual polarization radar according to the embodiment of the present invention. In this figure, reference numeral 309 denotes a large sway measurement value removing unit. Other symbols are the same as those described above. Next, the operation will be described.
[0117]
The deviation angle θ in the polarization direction from the motion sensor data _a Is calculated. Calculated θ _a Is larger than a preset threshold, the data output from the measurement value calculator is removed. Specifically, a missing value may be added to the measured value, or a mark indicating the missing value may be added.
[0118]
As a method of evaluating the magnitude of the fluctuation, for example, it is conceivable to determine whether the absolute value of the polarization shift angle exceeds a preset threshold value between the integration start time and the integration end time. Alternatively, simply, the amount of fluctuation at a certain time during the integration time, for example, the center time (average time) of the section of the integration time may be determined.
[0119]
In FIG. 8, the configuration of the dual polarization radar device is such that the transmission wave generated by one transmission unit is divided into two by the division unit, and the horizontal polarization and the vertical polarization are simultaneously transmitted. Some conventional dual polarization radar apparatuses have other configurations. For example, there is a method in which horizontal polarization and vertical polarization are observed alternately by switching both polarizations with a switch instead of transmitting horizontal polarization and vertical polarization simultaneously. Also in this case, the principle of performing the sway correction by signal processing can be similarly applied.
[0120]
FIG. 9 is a flowchart showing a flow of signal processing of the dual polarization radar device according to the embodiment of the present invention. The processing from steps st402 to st403 surrounded by steps st401 to st404 is repeated several times for integration. In step st402, a received signal for one hit is input. In step st403, the angle of deviation in the polarization direction (polarization deviation angle) is calculated from the roll, pitch, and yaw fluctuation data at the time when the data input in st402 is observed, and the value is accumulated.
[0121]
In step st405, a measured value is calculated using the received signals for the number of integrations input in step st402. In step st406, the one having the smallest absolute value is extracted from the integral several polarization shift angles calculated in st403. In step st407, it is determined whether or not the minimum value of the polarization shift angle extracted in step st406 exceeds a threshold value. If the threshold value has been exceeded, the measured value at that time is removed in step st408.
[0122]
According to the embodiment of the present invention, since only the signal processing result of the time during which the fluctuation is small is left, a measurement value having a large error due to the fluctuation is not output.
[0123]
【The invention's effect】
As described above, according to the dual-polarization radar device of the first aspect of the present invention, since the fluctuation of the ship is corrected by the signal processing, an accurate system without using a mechanism for stably maintaining the horizontal surface of the radar device itself is used. Double polarization observation becomes possible. Further, since the motion compensation is performed on the received signal before the integration process in the signal processing, there is an effect that the accuracy of the motion compensation is high.
[0124]
Further, according to the dual polarization radar apparatus of the present invention, since the fluctuation correction is performed on the measured value after the integration processing, the amount of calculation of the fluctuation correction can be reduced.
[0125]
According to the dual polarization radar apparatus of the present invention, since the measurement value is calculated using only the received signal in the time of small fluctuation, the measurement value is small and the error is small. Is obtained.
[0126]
According to the dual polarization radar apparatus of the fourth aspect of the present invention, since only the signal processing result during the time when the fluctuation is small is left, the measurement value having a large error due to the fluctuation is not output. There is.
[0127]
Further, according to the radar signal processing method of the present invention, since the motion correction is performed on the received signal before the integration process in the signal processing, there is an effect that the accuracy of the motion correction is high.
[0128]
Further, according to the radar signal processing method of the present invention, since the fluctuation correction is performed on the measured value after the integration processing, the amount of calculation of the fluctuation correction can be reduced.
[0129]
Further, according to the radar signal processing method of the present invention, since the smoothing is performed in the distance direction in the middle of the signal processing, there is an effect that the accuracy of the motion compensation is improved.
[0130]
Further, according to the radar signal processing method of the present invention, since the measurement value is calculated using only the reception signal of the time during which the fluctuation is small, a measurement value with a small amount of calculation and a small error is obtained. There is an effect that can be.
[0131]
Further, according to the radar signal processing method of the ninth aspect of the present invention, since only the signal processing result during the time when the fluctuation is small is left, there is an effect that a measurement value having a large error due to the fluctuation is not output. .
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of a dual polarization radar device according to a first embodiment of the present invention.
FIG. 2 is a flowchart showing a flow of a dual polarization radar signal processing method according to the first embodiment of the present invention.
FIG. 3 is a block diagram showing a configuration of a radar apparatus according to Embodiment 2 of the present invention.
FIG. 4 is a flowchart showing a flow of a dual polarization radar signal processing method according to a second embodiment of the present invention.
FIG. 5 is a flowchart showing another flow of the dual polarization radar signal processing method according to the second embodiment of the present invention.
FIG. 6 is a block diagram showing a configuration of a radar apparatus according to Embodiment 3 of the present invention.
FIG. 7 is a flowchart showing a flow of a dual polarization radar signal processing method according to a third embodiment of the present invention.
FIG. 8 is a block diagram showing a configuration of a radar apparatus according to Embodiment 4 of the present invention.
FIG. 9 is a flowchart showing a flow of a dual polarization radar signal processing method according to a fourth embodiment of the present invention.
FIG. 10 is a block diagram showing a configuration example of a conventional radar device.
[Explanation of symbols]
001 seed signal generation unit, 002 transmission unit, 003 division unit, 004A first transmission / reception switching unit, 004B second transmission / reception switching unit, 005 antenna, 006A first reception unit, 006B second reception unit, 007 signal processing Unit, 008A first AD conversion unit, 008B second AD conversion unit, 009 received signal fluctuation correction processing unit, 010 measurement value calculation unit, 109 measurement value fluctuation correction processing unit, 209 large fluctuation reception signal removal unit, 309 large Motion measurement value removal unit.

Claims

In a dual polarization radar device for measuring a measurement value of a dual polarization from a reception wave received by a horizontal polarization and a vertical polarization, a first reception unit that receives a reception wave by a horizontal polarization, and a vertical polarization: A second receiving unit for receiving the received wave, a sway sensor for measuring a roll angle, a pitch angle, and a yaw angle representing the sway of the radar device, and a polarization calculated from the roll angle, the pitch angle, and the yaw angle A vibration correction processing unit that corrects a signal of a horizontally polarized wave received from the first receiving unit and a vertically polarized wave received wave from the second receiving unit to remove the influence of the vibration by using the deviation angle of A dual-polarization radar device comprising: a measurement value calculating unit configured to calculate a measurement value of the dual polarization from the corrected horizontal polarization reception signal and the vertical polarization reception signal.

In a dual polarization radar device for measuring a measurement value of a dual polarization from a reception wave received by a horizontal polarization and a vertical polarization, a first reception unit that receives a reception wave by a horizontal polarization, and a vertical polarization: A second receiving unit for receiving a received wave, a measured value calculating unit for calculating a measured value of the double polarization from the horizontal polarized wave received signal and the vertical polarized wave received signal, and a fluctuation of the radar apparatus. Eliminates the effects of the sway from the measured values of the double polarization using the sway sensor that measures the roll angle, pitch angle, and yaw angle, and the polarization shift angle calculated from the roll angle, the pitch angle, and the yaw angle A dual-polarization radar device comprising: a fluctuation correction processing unit that performs correction.

In a dual polarization radar device for measuring a measurement value of a dual polarization from a reception wave received by a horizontal polarization and a vertical polarization, a first reception unit that receives a reception wave by a horizontal polarization, and a vertical polarization: A second receiving unit for receiving the received wave, a sway sensor for measuring a roll angle, a pitch angle, and a yaw angle representing the sway of the radar device, and a polarization calculated from the roll angle, the pitch angle, and the yaw angle And selecting and removing signals of the horizontally polarized reception wave from the first reception unit and the vertically polarization reception wave from the second reception unit based on a comparison between the deviation angle and the predetermined deviation angle threshold value. And a measurement value calculation unit that calculates the measurement value of the double polarization from the remaining horizontal polarization reception signal and vertical polarization reception signal after the removal. Heavy polarization radar device.

In a dual polarization radar device for measuring a measurement value of a dual polarization from a reception wave received by a horizontal polarization and a vertical polarization, a first reception unit that receives a reception wave by a horizontal polarization, and a vertical polarization: A second receiving unit for receiving a received wave, a measured value calculating unit for calculating a measured value of the double polarization from the horizontal polarized wave received signal and the vertical polarized wave received signal, and a fluctuation of the radar apparatus. A rocking sensor that measures a roll angle, a pitch angle, and a yaw angle, and the above-described double polarization based on a comparison between a polarization shift angle calculated from the roll angle, the pitch angle, and the yaw angle and a predetermined shift angle threshold value. A dual-polarization radar device comprising: a wobble signal removing unit that selects and removes a measured value of a wave.

What is claimed is: 1. A signal processing method for a dual polarization radar device for measuring a measurement value of a dual polarization from a received wave received by a horizontal polarization and a vertical polarization, comprising the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) a step of performing a wobble correction on the received signal of one pulse of the horizontal polarization and the vertical polarization using the deviation angle of the polarization.
(4) A step of repeating the processing of steps (1) to (3) for a plurality of pulses.
(5) A step of accumulating the received signals for N pulses by the processing of the step (4) and calculating the measured value of the double polarization for one time using the accumulated data.

What is claimed is: 1. A signal processing method for a dual polarization radar device for measuring a measurement value of a dual polarization from a received wave received by a horizontal polarization and a vertical polarization, comprising the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) A step of repeating the processing of steps (1) and (2) for a plurality of pulses.
(4) A step of accumulating the received signals for N pulses by the processing of the step (3), and calculating the measured value of the double polarization for one time using the accumulated data.
(4) a step of performing a wobble correction on the measured value of the double polarization for the one time using the deviation angle of the polarization by the processing of the step (3).

What is claimed is: 1. A signal processing method for a dual polarization radar device for measuring a measurement value of a dual polarization from a received wave received by a horizontal polarization and a vertical polarization, comprising the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) A step of repeating the processing of steps (1) and (2) for a plurality of pulses.
(4) The received signals of N pulses are accumulated by the processing of the above step (3), and the magnitude and phase of the inter-polarization intensity ratio and the inter-polarization cross-correlation coefficient for one time are calculated using the accumulated data. Step.
(5) A step of performing a distance direction smoothing process on at least one of the calculated values of the intensity ratio between polarizations and the magnitude or phase of the cross-correlation coefficient between polarizations.
(6) The inter-polarization intensity ratio, the magnitude and the phase of the cross-polarization cross-correlation coefficient on which the smoothing processing has been performed in the processing of the step (5), and the parameter on which the smoothing processing has not been performed are described in the step (4). B) calculating the double-polarized wave measurement value for one time using the combination of the polarization intensity ratio, the magnitude of the cross-polarization cross-correlation coefficient, and the phase calculated in the processing of the above).
(7) a step of performing a wobble correction on the measured value of the double polarization for the one time using the deviation angle of the polarization by the processing of the step (3).

What is claimed is: 1. A signal processing method for a dual polarization radar device for measuring a measurement value of a dual polarization from a received wave received by a horizontal polarization and a vertical polarization, comprising the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) a step of selecting and removing the signals of the horizontally polarized reception wave and the vertically polarized reception wave based on a comparison between the deviation angle of the polarization and a predetermined deviation angle threshold value.
(4) A step of repeating the processing of steps (1) to (3) for a plurality of pulses.
(5) A step of accumulating the received signals for N pulses by the processing of the step (4) and calculating the measured value of the double polarization for one time using the accumulated data.

What is claimed is: 1. A signal processing method for a dual polarization radar device for measuring a measurement value of a dual polarization from a received wave received by a horizontal polarization and a vertical polarization, comprising the following steps.
(1) A step of inputting a horizontal polarization and a vertical polarization reception signal for one pulse.
(2) calculating a polarization shift angle from a roll angle, a pitch angle, and a yaw angle representing the oscillation of the radar device;
(3) A step of repeating the processing of steps (1) and (2) for a plurality of pulses.
(4) A step of accumulating the received signals for N pulses by the processing of the step (3), and calculating the measured value of the double polarization for one time using the accumulated data.
(5) a step of selecting and removing the measured value of the double polarization for the one time based on the comparison between the polarization shift angle and a predetermined shift angle threshold value.