JP2010223870A - Target azimuth calculating device - Google Patents

Target azimuth calculating device Download PDF

Info

Publication number
JP2010223870A
JP2010223870A JP2009073632A JP2009073632A JP2010223870A JP 2010223870 A JP2010223870 A JP 2010223870A JP 2009073632 A JP2009073632 A JP 2009073632A JP 2009073632 A JP2009073632 A JP 2009073632A JP 2010223870 A JP2010223870 A JP 2010223870A
Authority
JP
Japan
Prior art keywords
phase difference
azimuth
target
measurement system
delay line
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
JP2009073632A
Other languages
Japanese (ja)
Other versions
JP5278083B2 (en
Inventor
Akira Kato
彰 加藤
Masaaki Kobayashi
正明 小林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Mitsubishi Electric Corp
Original Assignee
Mitsubishi Electric Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mitsubishi Electric Corp filed Critical Mitsubishi Electric Corp
Priority to JP2009073632A priority Critical patent/JP5278083B2/en
Publication of JP2010223870A publication Critical patent/JP2010223870A/en
Application granted granted Critical
Publication of JP5278083B2 publication Critical patent/JP5278083B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Landscapes

  • Radar Systems Or Details Thereof (AREA)

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem, wherein it is necessary that a receiving phase difference is 2° or below per 1° of target azimuth change to have limits on direction finder precision, as a result allowing ±90° of an azimuth range to correspond to a phase difference within ±180° so as not to generate azimuth ambiguity (a plurality of azimuths are calculated from one phase difference information) in a direction finder region (azimuth range of ±90°) in the conventional phase difference direction finder system in a target azimuth calculating device for receiving incoming radio waves from targets and calculate the target azimuth. <P>SOLUTION: In addition to an azimuth calculation means (precision system) due to conventional phase difference direction finder systems, the target azimuth calculating device detects the phase difference due to a micro-Doppler frequency difference in the signals received with two antenna elements after a delay line is passed and increased, and includes a roughing system for performing right and left determination of target azimuth. As a result, the effect for obtaining direction finder accuracy for the two times of the conventional phase difference direction finder system is taken. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

本発明は、地上レーダ等の目標から到来する信号電波を、航空機等の高速移動体上で受信して目標の方位を算出する目標方位算出装置に関するものである。   The present invention relates to a target azimuth calculation apparatus that receives a signal radio wave arriving from a target such as a ground radar on a high-speed moving body such as an aircraft and calculates a target azimuth.

従来から、２つのアンテナ素子で受信した目標電波の到来時間差に起因する位相差を利用して目標電波の到来方位を探知する「位相差方探（方位探知）方式」が有る。
この方式では、到来電波を２つのアンテナ素子で受信し、高周波増幅器で増幅後、Ａ／Ｄ変換器でデジタル信号に変換する。デジタル信号を、それぞれ高速フーリエ変換し、互いのクロススペクトルを計算する。得られたクロススペクトルのコヒーレンスと位相から、コヒーレンスのレベルの高い周波数帯における位相の傾きを求め、到来時間差、目標方位を算出している。（例えば、特許文献１参照。） Conventionally, there is a “phase difference method (orientation detection) method” that detects an arrival direction of a target radio wave using a phase difference caused by a difference in arrival time of target radio waves received by two antenna elements.
In this method, incoming radio waves are received by two antenna elements, amplified by a high frequency amplifier, and then converted into a digital signal by an A / D converter. Each digital signal is fast Fourier transformed, and the cross spectrum of each other is calculated. From the obtained coherence and phase of the cross spectrum, the slope of the phase in a frequency band with a high level of coherence is obtained, and the arrival time difference and the target direction are calculated. (For example, refer to Patent Document 1.)

特開平９−２５７９０２号公報（１２頁，図１）Japanese Patent Laid-Open No. 9-257902 (page 12, FIG. 1)

ＥＷ １０１ Ａ Ｆｉｒｓｔ Ｃｏｕｒｓｅ ｉｎ Ｅｌｅｃｔｒｏｎｉｃ Ｗａｒｆａｒｅ， ＡＲＴＥＣＨ ＨＯＵＳＥ，ＩＮＣ．， （Ｃ）２００１， ｐ１７１EW 101 A First Course in Electronic Warfare, ARTEC HOUSE, INC. , (C) 2001, p171 ＩＥＥＥ ＴＲＡＮＳＡＣＴＩＯＮＳ ＯＮ ＡＮＴＥＮＮＡＳ ＡＮＤ ＰＲＯＰＡＧＡＴＩＯＮ， ＶＯＬ．５２，ＮＯ．１２， ＤＥＣＥＭＢＥＲ ２００４ ｐ３３１９〜３３２８IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 52, NO. 12, DECEMBER 2004 p3319-3328

位相差方探方式では、２つのアンテナ素子で高周波電波を受信する場合に、到来電波の位相差が±１８０°の範囲を越えると、到来時間差に起因する位相差が同一である方位が複数存在するため、正確な到来方位を検出できないという「方位アンビギュイティ」が生じる。
従来は、方探覆域内（±９０°の方位範囲内）に、このような方位アンビギュイティを発生させないように、アンテナ素子間隔Ｄを波長λの１／２以下に設定することにより、到来電波の位相差が±１８０°以内となるようにし、±９０°の方位範囲に対応させていた。（図９参照）。
このため、目標方位の１°の変化を位相差で２°以下の変化とする必要があった。すなわち、わずかな目標方位の変化を大きな位相差の変化に増幅して検出できないため、方探精度に限界が生じていた。 In the phase difference detection method, when high frequency radio waves are received by two antenna elements, if the phase difference of the incoming radio waves exceeds the range of ± 180 °, there are multiple orientations with the same phase difference due to the arrival time difference. Therefore, an “azimuth ambiguity” occurs in which an accurate arrival direction cannot be detected.
Conventionally, the antenna element interval D is set to be ½ or less of the wavelength λ so as not to generate such azimuth ambiguity in the direction finding area (within ± 90 ° azimuth range). The phase difference of the radio wave is set within ± 180 °, and it corresponds to the azimuth range of ± 90 °. (See FIG. 9).
For this reason, it has been necessary to change a change of 1 ° in the target azimuth to a change of 2 ° or less in phase difference. That is, since the slight change in the target orientation cannot be detected by amplifying the change in the large phase difference, the direction finding accuracy is limited.

上記の課題を解決するために、本発明では、アンテナ素子間隔Ｄをλ（λは到来電波の波長）まで広げる。また、２つの受信信号の微小なドップラー周波数差（非特許文献１，Ｆｉｇｕｒｅ８．３１参照。）による位相差を遅延線により増加させて検出する。（非特許文献２参照。）
この検出結果を用いて、目標位置の左右領域を判定する粗方位算出手段（以降「粗測系」と記述する）を、従来からの方位算出手段（以降「精測系」と記述する）に加える。 In order to solve the above problems, in the present invention, the antenna element interval D is expanded to λ (λ is the wavelength of the incoming radio wave). In addition, a phase difference due to a minute Doppler frequency difference between the two received signals (see Non-Patent Document 1, FIG. 8.31) is increased by a delay line and detected. (See Non-Patent Document 2.)
Using this detection result, the rough azimuth calculation means (hereinafter referred to as “rough measurement system”) for determining the left and right regions of the target position is replaced with the conventional azimuth calculation means (hereinafter referred to as “precision measurement system”). Add.

本発明の方探方式では、方探覆域（±９０°の方位範囲内）のうち、左側（方位−９０°〜０°）の範囲を±１８０°の位相差に対応させ、右側（方位０°〜＋９０°）の範囲を同じく±１８０°の位相差に対応させることができるため、従来の位相差方探方式の２倍の方探精度を得ることができる。
また、２つの受信信号の微小なドップラー周波数差による位相差を遅延線により増加させて検出することにより、位相差の符号（正負）から目標の方位が左右いずれの領域か判定できるので、方位アンビギュイティも解消される。 In the direction finding method of the present invention, in the direction finding area (within ± 90 ° azimuth range), the left side (azimuth −90 ° to 0 °) range corresponds to the phase difference of ± 180 ° and the right side (azimuth) The range of 0 ° to + 90 ° can be made to correspond to a phase difference of ± 180 °, so that it is possible to obtain a direction finding accuracy twice that of the conventional phase difference direction finding method.
Further, by detecting the phase difference due to the minute Doppler frequency difference between the two received signals by increasing the delay line, it is possible to determine whether the target direction is the left or right region from the sign (positive / negative) of the phase difference. Guyty is also eliminated.

この発明の実施の形態１を示す目標方位算出装置の構成図。BRIEF DESCRIPTION OF THE DRAWINGS The block diagram of the target direction calculation apparatus which shows Embodiment 1 of this invention. この発明の実施の形態１を示す目標方位算出装置のフローチャート。The flowchart of the target direction calculation apparatus which shows Embodiment 1 of this invention. 位相差方探方式の原理説明図。The principle explanatory view of a phase difference method. この発明の実施の形態１の精測系における位相差から目標方位の計算例。The example of calculation of a target azimuth | direction from the phase difference in the precise measurement system of Embodiment 1 of this invention. この発明の実施の形態１の精測系における位相差と目標方位の関係。The relationship between the phase difference and the target azimuth | direction in the precise measurement system of Embodiment 1 of this invention. この発明の実施の形態１の粗測系における遅延線通過後の位相差計算モデル。3 is a phase difference calculation model after passing through a delay line in the rough measurement system according to the first embodiment of the present invention. この発明の実施の形態１の粗測系における遅延線通過後の位相差計算例。FIG. 6 is a phase difference calculation example after passing through the delay line in the rough measurement system according to the first embodiment of the present invention. FIG. この発明の実施の形態１の粗測系における位相差増加と左右判定。Phase difference increase and right / left determination in the rough measurement system according to the first embodiment of the present invention. 従来の位相差方探方式における目標方位と位相差の関係。Relationship between target orientation and phase difference in the conventional phase difference method.

実施の形態１．
この発明の実施の形態１における構成について図１を用いて説明する。
１は目標から到来する電波を受信する第１のアンテナ素子、２はアンテナ素子１との間隔Ｄの位置に設けられ到来電波を受信する第２のアンテナ素子、
３ａ，３ｂはアンテナ素子１及び２で受信した各チャンネルのＲＦ信号（高周波信号）を周波数変換（ダウンコンバート）してＩＦ信号（中間周波信号）に変換する周波数変換器、４ａ，４ｂは２チャンネルのＩＦ信号を分配して精測系５及び粗測系６へ給電する分配器、５は２チャンネルのＩＦ信号の位相差を算出する位相差算出器８ａを有する精測系、６は遅延線７及び位相差算出器８ｂを有する粗測系である。
７ａ，７ｂは粗測系６において２チャンネルのＩＦ信号を遅延させる遅延線、８ｂは粗測系６において遅延線７ａ，７ｂに接続され２チャンネルのＩＦ信号の位相差を算出する位相差算出器である。位相差算出器８ａ，８ｂはＩＦ信号をＡ／Ｄ変換し高速フーリエ変換し、互いのクロススペクトルから位相差を算出するもので、特許文献１に記載されたものと同じ回路構成である。 Embodiment 1 FIG.
A configuration according to Embodiment 1 of the present invention will be described with reference to FIG.
1 is a first antenna element that receives radio waves coming from a target, 2 is a second antenna element that is provided at a distance D from the antenna element 1 and receives incoming radio waves,
3a and 3b are frequency converters for converting the RF signals (high-frequency signals) received by the antenna elements 1 and 2 into IF signals (intermediate frequency signals) by frequency conversion (down-conversion), and 4a and 4b are two channels. A distributor for distributing the IF signal to the precision measuring system 5 and the rough measuring system 6, 5 is a precision measuring system having a phase difference calculator 8 a for calculating the phase difference of the two-channel IF signals, and 6 is a delay line. 7 and a rough measurement system having a phase difference calculator 8b.
Reference numerals 7a and 7b denote delay lines for delaying the two-channel IF signals in the rough measurement system 6, and reference numerals 8b denote phase difference calculators that are connected to the delay lines 7a and 7b in the rough measurement system 6 and calculate the phase difference between the two-channel IF signals. It is. The phase difference calculators 8a and 8b perform A / D conversion and fast Fourier transform on the IF signal, and calculate a phase difference from each other's cross spectrum, and have the same circuit configuration as that described in Patent Document 1.

９は精測系５及び粗測系６から出力された位相差情報を用いて目標の方位を高精度に算出する方位算出器である。ここで、９１は精測系５から出力された位相差Δφ１を用いて方位候補を求める方位候補算出器、９２は粗測系６から出力された位相差Δφ２及びΔφ１を用いて目標方位が方探覆域のうち左側（方位−９０°〜０°）か右側（方位０°〜＋９０°）かを判定する左右判定器、９３は方位候補算出器９１と左右判定器９２からの出力結果を用いて目標電波の到来方位を決定する方位決定器である。   Reference numeral 9 denotes an azimuth calculator that calculates the target azimuth with high accuracy using the phase difference information output from the precise measurement system 5 and the rough measurement system 6. Here, 91 is an azimuth candidate calculator for obtaining azimuth candidates using the phase difference Δφ1 output from the precise measurement system 5, and 92 is the target azimuth using the phase differences Δφ2 and Δφ1 output from the coarse measurement system 6. A left / right determination unit 93 determines whether the left side (azimuth −90 ° to 0 °) or right side (azimuth 0 ° to + 90 °) in the detection area, and 93 indicates the output results from the direction candidate calculator 91 and the left / right determination unit 92. It is an azimuth determiner that determines the arrival azimuth of the target radio wave.

次にこの発明の実施の形態１において目標方位を高精度に算出する処理を示すフローチャートを図２により説明する。
まず、ステップＳ１０１で、目標から到来した電波をアンテナ素子１及び２で受信する。ステップＳ１０２で、受信した２チャンネルのＲＦ信号（高周波信号）を周波数変換器３ａ，３ｂによりＩＦ信号（中間周波信号）に変換する。
次に、ステップＳ１０３で、精測系５の位相差算出器８ａで２チャンネルのＩＦ信号の位相差Δφ１を算出する。ステップＳ１０４で、この位相差算出結果に基づき方位候補算出器９１は方位候補を算出する。このとき、目標方位候補は素子アンテナ正面方位に対して右側から１方位、左側から１方位の合計２方位が算出される。これについては後に図７を用いて細部を説明する。 Next, a flowchart showing processing for calculating the target orientation with high accuracy in the first embodiment of the present invention will be described with reference to FIG.
First, in step S101, radio waves arriving from the target are received by the antenna elements 1 and 2. In step S102, the received two-channel RF signals (high frequency signals) are converted into IF signals (intermediate frequency signals) by the frequency converters 3a and 3b.
Next, in step S103, the phase difference calculator 8a of the precise measurement system 5 calculates the phase difference Δφ1 of the two-channel IF signals. In step S104, the azimuth candidate calculator 91 calculates azimuth candidates based on the phase difference calculation result. At this time, the target azimuth candidates are calculated as a total of two azimuths, one azimuth from the right side and one azimuth from the left side with respect to the front direction of the element antenna. Details will be described later with reference to FIG.

次にステップＳ１０５で、粗測系６の位相差算出器８ｂにより遅延線７ａ，７ｂを通過した２チャンネルのＩＦ信号の位相差Δφ２を算出する。
ステップＳ１０６で、位相差算出結果に基づき左右判定器９２にて、精測系５で算出した位相差Δφ１と粗測系６で算出した位相差Δφ２の大小を比較する。
Δφ１＜Δφ２のとき、目標方位は右側と判定する。
Δφ１＞Δφ２のとき、目標方位は左側と判定する。
ステップ１０７にて方位決定器９３は、目標方位が右側と判定された場合は、方位候補算出器９１で算出した目標方位候補のうち右側に決定する。
目標方位が左側と判定された場合は、目標方位候補のうち左側に決定し、方位算出結果を出力する。これについては後に図８を用いて細部を説明する。 In step S105, the phase difference calculator 8b of the rough measuring system 6 calculates the phase difference Δφ2 of the IF signals of the two channels that have passed through the delay lines 7a and 7b.
In step S106, the right / left determination unit 92 compares the phase difference Δφ1 calculated by the precise measurement system 5 with the phase difference Δφ2 calculated by the rough measurement system 6 based on the phase difference calculation result.
When Δφ1 <Δφ2, the target orientation is determined to be the right side.
When Δφ1> Δφ2, the target orientation is determined to be the left side.
If it is determined in step 107 that the target direction is the right side, the direction determining unit 93 determines the right side among the target direction candidates calculated by the direction candidate calculating unit 91.
When the target azimuth is determined to be the left side, the target azimuth candidate is determined to the left side, and the azimuth calculation result is output. Details will be described later with reference to FIG.

次に図２で示したフローチャートの各部について実際の計算例を示しながら細部を説明する。
まず、精測系５で算出した位相差Δφ１から目標方位候補（左右それぞれ１候補 合計２候補）を方位候補算出器９１にて算出する手順を説明する。位相差方探方式により受信した２チャンネル間の位相差Δφ１は、図３の原理説明図に示すように、次式で表される。 Next, details of each part of the flowchart shown in FIG. 2 will be described with reference to actual calculation examples.
First, a procedure for calculating a target orientation candidate (one candidate for each of left and right, a total of two candidates) by the orientation candidate calculator 91 from the phase difference Δφ1 calculated by the precise measurement system 5 will be described. The phase difference Δφ1 between the two channels received by the phase difference search method is expressed by the following equation as shown in the principle explanatory diagram of FIG.

Figure 2010223870
ここで、Ｄは２つのアンテナ素子が設置されている間隔、θは目標電波の到来方位、λは到来電波の波長である。
Figure 2010223870
 Here, D is the interval at which the two antenna elements are installed, θ is the arrival direction of the target radio wave, and λ is the wavelength of the incoming radio wave.

実際の計算例を図４に、計算結果のグラフを図５に示す。
図５の横軸は目標方位θであり、Ｄ＝λとして、方探覆域の左側（方位−９０°〜０°）の範囲を±１８０°の位相差Δφ１に対応させ、右側（方位０°〜＋９０°）の範囲を同じく±１８０°のΔφ１に対応させる。
なお、Δφ１は±１８０°の範囲内であるので、１８０°を越えた場合は１周期（３６０°）マイナスし、−１８０°未満となる場合は３６０°プラスする。例えば、θ＝４０°の場合、３６０・ｓｉｎ４０°＝２３１．４°となるが、３６０°マイナスし、−１２８．６°となる。
図４に示す計算例では、Ｄ＝λであり、精測系５から算出された位相差Δφ１＝−１２８．６［ｄｅｇ］となっている。
Δφ１が−１２８．６［ｄｅｇ］となる方位候補を（１）式及び図５から求めると、右側（θ＞０°）から１方位（４０［ｄｅｇ］）、左側（θ＜０°）から１方位（−２０．９［ｄｅｇ］）、合計２方位が候補として求められる。 FIG. 4 shows an actual calculation example, and FIG. 5 shows a graph of the calculation results.
The horizontal axis of FIG. 5 is the target azimuth θ, D = λ, the range on the left side (azimuth −90 ° to 0 °) of the direction finding area is made to correspond to the phase difference Δφ1 of ± 180 °, and the right side (azimuth 0) Similarly, the range of (° to + 90 °) corresponds to Δφ1 of ± 180 °.
Since Δφ1 is within a range of ± 180 °, if it exceeds 180 °, it is decremented by one period (360 °), and if it is less than −180 °, it is incremented by 360 °. For example, in the case of θ = 40 °, 360 · sin 40 ° = 231.4 °, but 360 ° is minus and becomes −128.6 °.
In the calculation example shown in FIG. 4, D = λ, and the phase difference Δφ1 calculated from the precise measurement system 5 is −128.6 [deg].
When an azimuth candidate having Δφ1 of −128.6 [deg] is obtained from the equation (1) and FIG. 5, from the right side (θ> 0 °), one azimuth (40 [deg]), and from the left side (θ <0 °). One direction (-20.9 [deg]) and a total of two directions are obtained as candidates.

従来の位相差方探方式では、図９に示すように、到来電波の波長λに対して、アンテナ素子の間隔Ｄをλ／２に設定し方探覆域（±９０°の方位範囲内）に方位アンビギュイティ（１つの位相差情報から複数の方位が算出されてしまうこと）を発生させないようにしていた。
しかし、本発明では方探精度を２倍に向上させるため、アンテナ素子間隔Ｄを従来の２倍すなわちλに設定する。これにより、方探覆域（±９０°の方位範囲内）のうち、左側（方位−９０°〜０°）の範囲を±１８０°の位相差に対応させ、右側（方位０°〜＋９０°）の範囲を同じく±１８０°の位相差に対応させている。この結果、図５に示すように方位候補が左右２つ求まる。 In the conventional phase difference detection method, as shown in FIG. 9, the distance D of the antenna elements is set to λ / 2 with respect to the wavelength λ of the incoming radio wave, and the direction detection area (within ± 90 ° azimuth range). Azimuth ambiguity (a plurality of directions are calculated from one phase difference information) is not generated.
However, in the present invention, in order to improve the direction finding accuracy twice, the antenna element interval D is set to twice the conventional value, that is, λ. Thereby, in the direction finding area (within ± 90 ° azimuth range), the range on the left side (azimuth −90 ° to 0 °) corresponds to the phase difference of ± 180 °, and the right side (azimuth 0 ° to + 90 °). ) In the same manner corresponds to a phase difference of ± 180 °. As a result, as shown in FIG. 5, two azimuth candidates are obtained.

次に、粗測系６の位相差算出器８ｂにおいて遅延線７ａ，７ｂを通過した２チャンネルのＩＦ信号の位相差算出結果Δφ２から、目標方位の左右を判定する（すなわち２つの方位候補から１つに絞り込む）手順について説明する。
図６には計算モデルを示し、図７には計算例として計算式及び数値例を示している。図６に示す計算モデルより、目標電波の到来方位をθ、目標までの距離をＲとすると、目標位置（ｘ，ｙ）は次のように表される。 Next, the right and left of the target azimuth is determined from the phase difference calculation result Δφ2 of the two-channel IF signals that have passed through the delay lines 7a and 7b in the phase difference calculator 8b of the rough measurement system 6 (that is, 1 from two azimuth candidates). The procedure for narrowing down to one is explained.
FIG. 6 shows a calculation model, and FIG. 7 shows calculation formulas and numerical examples as calculation examples. From the calculation model shown in FIG. 6, when the arrival direction of the target radio wave is θ and the distance to the target is R, the target position (x, y) is expressed as follows.

Figure 2010223870
また、アンテナ素子１及びアンテナ素子２から目標を見た方位θ１及びθ２は以下の式で表される。
Figure 2010223870
 Further, the azimuths θ1 and θ2 when the target is viewed from the antenna element 1 and the antenna element 2 are expressed by the following equations.

Figure 2010223870
Figure 2010223870

Figure 2010223870
Figure 2010223870

従って、本発明の方位算出装置を搭載した自機が、アンテナ素子の正面方向に向かって速度Ｖで高速移動していると仮定すると、アンテナ素子１で受信したチャンネル（ＣＨ）１受信信号及びアンテナ素子２で受信したチャンネル（ＣＨ）２受信信号のドップラー周波数ｆ１及びｆ２は以下の式で表される。   Therefore, if it is assumed that the own device equipped with the direction calculating device of the present invention is moving at a high speed V in the front direction of the antenna element, the channel (CH) 1 received signal received by the antenna element 1 and the antenna The Doppler frequencies f1 and f2 of the channel (CH) 2 received signal received by the element 2 are expressed by the following equations.

Figure 2010223870
Figure 2010223870

Figure 2010223870
Figure 2010223870

Figure 2010223870
Figure 2010223870

Figure 2010223870
ここで、ｆＲＦ：到来電波の周波数、ｃ ：光速、
Ｖ１：アンテナ素子１から見たドップラー速度成分、
Ｖ２：アンテナ素子２からみたドップラー速度成分、Ｖ ：自機の移動速度、
θ１：アンテナ素子１から見た目標方位、θ２：アンテナ素子２から見た目標方位、
である。
上記に基づき、ＣＨ１受信信号とＣＨ２受信信号の周波数差Δｆを求めると次の通りとなる。
Figure 2010223870
 Where fRF: frequency of incoming radio wave, c: speed of light,
V1: Doppler velocity component viewed from the antenna element 1
V2: Doppler velocity component as seen from antenna element 2, V: movement speed of own aircraft,
θ1: target orientation viewed from antenna element 1, θ2: target orientation viewed from antenna element 2,
It is.
Based on the above, the frequency difference Δf between the CH1 received signal and the CH2 received signal is obtained as follows.

Figure 2010223870
この周波数差Δｆは、図７に示した数値例では１．６Ｈｚと非常に微小（Ｈｚオーダ）であり検出することは技術的に困難である。そこで遅延線を通過させることにより２チャンネルの信号の微小な周波数差による位相差を増加させて検出する。
微小な周波数差Δｆを有する２チャンネルの受信信号を、遅延時間Ｔの遅延線７を通過させた結果得られる位相差増加量Δφｄ〔ｄｅｇ〕は次の式で表される。
Figure 2010223870
 This frequency difference Δf is very small (Hz order) as 1.6 Hz in the numerical example shown in FIG. 7, and it is technically difficult to detect. Therefore, by passing through the delay line, the phase difference due to a minute frequency difference between the signals of the two channels is increased and detected.
A phase difference increase amount Δφd [deg] obtained as a result of passing a two-channel received signal having a minute frequency difference Δf through the delay line 7 having a delay time T is expressed by the following equation.

Figure 2010223870
従って粗測系６の位相差算出器８ｂで遅延線７を通過した２チャンネルのＩＦ信号の位相差算出結果Δφ２は以下の式で表される。（図８参照）
Figure 2010223870
 Accordingly, the phase difference calculation result Δφ2 of the two-channel IF signals that have passed through the delay line 7 by the phase difference calculator 8b of the rough measurement system 6 is expressed by the following equation. (See Figure 8)

Figure 2010223870
ここで、Δφ１：精測系５における位相差算出結果、
Δφｄ：粗測系６にて遅延線７通過による位相差増加量。
Figure 2010223870
 Here, Δφ1: phase difference calculation result in the precise measurement system 5,
Δφd: A phase difference increase amount due to the passage of the delay line 7 in the rough measurement system 6.

次に、粗測系６における目標方位の左右判定方法を説明する。
図６の計算モデルに示すように、目標がアンテナ素子正面より左側（θ＜０°）に位置する場合にはＶ１＜Ｖ２であり、結果Δφｄが負の値となるため、Δφ１＞Δφ２となる。一方、目標がアンテナ素子正面より右側（θ＞０°）に位置する場合には、Ｖ１＞Ｖ２であり結果Δφｄが正の値となるため、Δφ１＜Δφ２となる。（図８参照）。
従って、方位算出器９における左右判定は、精測系５から出力された位相差Δφ１及び、粗測系６から出力された位相差Δφ２を用いて、
Δφ１＞Δφ２のとき、目標方位は「左側」と判定し、
Δφ１＜Δφ２のとき、目標方位は「右側」と判定する。
この判定の結果、図５に示した精測系５で算出した左右２つの目標方位候補から１つが求まり、高精度の算出結果が出力される。 Next, the right / left determination method of the target direction in the rough measurement system 6 will be described.
As shown in the calculation model of FIG. 6, when the target is located on the left side (θ <0 °) from the front of the antenna element, V1 <V2, and the result Δφd becomes a negative value, so Δφ1> Δφ2. . On the other hand, when the target is located on the right side (θ> 0 °) from the front of the antenna element, V1> V2 and the result Δφd has a positive value, so Δφ1 <Δφ2. (See FIG. 8).
Therefore, the left / right determination in the azimuth calculator 9 uses the phase difference Δφ1 output from the precise measurement system 5 and the phase difference Δφ2 output from the rough measurement system 6,
When Δφ1> Δφ2, the target direction is determined as “left side”,
When Δφ1 <Δφ2, the target orientation is determined to be “right side”.
As a result of this determination, one is obtained from the two left and right target orientation candidates calculated by the precise measurement system 5 shown in FIG. 5, and a highly accurate calculation result is output.

なお、粗測系６の位相差Δφ２を算出する際には、長時間（遅延線７の遅延時間Ｔ）周回し遅延した後の出力信号を短時間測定するだけでは２チャンネル間の位相差を正しく観測することはできない。遅延線の遅延時間Ｔ全時間について信号サンプリングを実施し、このサンプリングデータを用いて、位相差算出器８ｂにより位相差を高精度に求める必要がある点に注意が必要である。（非特許文献２を参照。）   When calculating the phase difference Δφ2 of the rough measurement system 6, the phase difference between the two channels can be calculated by simply measuring the output signal after being delayed for a long time (delay time T of the delay line 7). It cannot be observed correctly. It should be noted that it is necessary to perform signal sampling for the entire delay time T of the delay line and to obtain the phase difference with high accuracy by the phase difference calculator 8b using this sampling data. (See Non-Patent Document 2.)

また、粗測系６において、２チャンネルのＩＦ信号を遅延させる遅延線７ａ，７ｂは、ＩＦ信号を遅延させることができるマイクロ波ケーブル等でもよいが、極力ＩＦ信号の電力を減衰させることなく遅延させることができる光ファイバー遅延線などが望ましい。   In the coarse measurement system 6, the delay lines 7a and 7b for delaying the IF signal of the two channels may be a microwave cable or the like capable of delaying the IF signal. However, the delay lines 7a and 7b are delayed without attenuating the power of the IF signal as much as possible. An optical fiber delay line that can be used is desirable.

更に、精測系５の位相差算出器８ａと粗測系６の位相差算出器８ｂとは、同じものを使用している。また、粗測系６では遅延時間Ｔだけ遅延することを考慮すると、精測系５と粗測系６の位相差算出器を共用することも可能である。つまり、精測系５にて位相差Δφ１を算出した後に、粗測系６にて同じ位相差算出器を用いても位相差Δφ２を算出するように構成できる。   Furthermore, the phase difference calculator 8a of the precise measurement system 5 and the phase difference calculator 8b of the rough measurement system 6 are the same. In consideration of the delay in the rough measurement system 6 by the delay time T, the phase difference calculators of the precision measurement system 5 and the rough measurement system 6 can be shared. That is, after calculating the phase difference Δφ1 in the precise measurement system 5, the phase difference Δφ2 can be calculated even if the same phase difference calculator is used in the rough measurement system 6.

本発明の方探方式では、方探覆域（±９０°の方位範囲内）のうち、左側（方位−９０°〜０°）の範囲を±１８０°の位相差に対応させ、右側（方位０°〜＋９０°）の範囲を同じく±１８０°の位相差に対応させることができるため、従来の位相差方探方式の２倍の方探精度を得ることができる。
また、２つの受信信号の微小なドップラー周波数差による位相差を遅延線により増加させて検出することにより、目標の方位が左右いずれの領域か判定できるので、方位アンビギュイティも解消される。 In the direction finding method of the present invention, in the direction finding area (within ± 90 ° azimuth range), the left side (azimuth −90 ° to 0 °) range corresponds to the phase difference of ± 180 ° and the right side (azimuth) The range of 0 ° to + 90 ° can be made to correspond to a phase difference of ± 180 °, so that it is possible to obtain a direction finding accuracy twice that of the conventional phase difference direction finding method.
Further, by detecting the phase difference due to a minute Doppler frequency difference between the two received signals by increasing the delay line, it is possible to determine whether the target azimuth is the left or right region, thereby eliminating the azimuth ambiguity.

１：アンテナ素子１、２：アンテナ素子２、３ａ，３ｂ：周波数変換器、
４ａ，４ｂ：分配器、５：精測系、６：粗測系、７ａ，７ｂ：遅延線、
８ａ，８ｂ位相差算出器、９：方位算出器、
９１：方位候補算出器、９２：左右判定器、９３：方位決定器。 1: antenna element 1, 2: antenna element 2, 3a, 3b: frequency converter,
4a, 4b: distributor, 5: precision measurement system, 6: rough measurement system, 7a, 7b: delay line,
8a, 8b phase difference calculator, 9: bearing calculator,
91: Direction candidate calculator, 92: Left / right determination unit, 93: Direction determination unit.

Claims (2)

高速移動体に設けられ目標から到来する電波を受信し目標の方位を算出する目標方位算出装置において、
到来する電波を受信する２つのアンテナ素子と、
前記アンテナ素子で受信した各信号を分配し精測系及び粗測系へ給電する分配器と、
前記分配された各信号の位相差を算出する位相差算出器を有する精測系と、
前記分配された各信号を遅延させる遅延線及びこの遅延線を通過した各信号の位相差を算出する位相差算出器を有する粗測系と、
前記精測系から出力した位相差より前記高速移動体の進行方向に対する左右の領域について各々目標方位候補を算出し、前記粗測系から出力した位相差より前記左右の領域のいずれであるかを判定し目標方位を決定する方位算出器と
を備えたことを特徴とする目標方位算出装置。 In a target azimuth calculation device that is provided in a high-speed moving body and receives radio waves coming from a target and calculates the azimuth of the target,
Two antenna elements for receiving incoming radio waves,
A distributor that distributes each signal received by the antenna element and supplies power to the precision measurement system and the coarse measurement system;
A precision measuring system having a phase difference calculator for calculating a phase difference of each of the distributed signals;
A rough measurement system having a delay line for delaying each distributed signal and a phase difference calculator for calculating a phase difference of each signal passing through the delay line;
A target orientation candidate is calculated for each of the left and right regions with respect to the traveling direction of the high-speed moving body from the phase difference output from the precise measurement system, and whether the left or right region is from the phase difference output from the rough measurement system. A target azimuth calculation device comprising: an azimuth calculator for determining and determining a target azimuth. 前記遅延線として、光ファイバー遅延線又はマイクロ波ケーブル遅延線を用いたことを特徴とする請求項１に記載の目標方位算出装置。 The target azimuth calculating apparatus according to claim 1, wherein an optical fiber delay line or a microwave cable delay line is used as the delay line.
JP2009073632A 2009-03-25 2009-03-25 Target orientation calculation device Active JP5278083B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2009073632A JP5278083B2 (en) 2009-03-25 2009-03-25 Target orientation calculation device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2009073632A JP5278083B2 (en) 2009-03-25 2009-03-25 Target orientation calculation device

Publications (2)

Publication Number Publication Date
JP2010223870A true JP2010223870A (en) 2010-10-07
JP5278083B2 JP5278083B2 (en) 2013-09-04

Family

ID=43041199

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2009073632A Active JP5278083B2 (en) 2009-03-25 2009-03-25 Target orientation calculation device

Country Status (1)

Country Link
JP (1) JP5278083B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101201900B1 (en) * 2011-02-01 2012-11-16 국방과학연구소 The method and apparatus for eleminationg path phase error generated at the direction finder
CN105445715A (en) * 2015-11-24 2016-03-30 大连楼兰科技股份有限公司 Method for improving radar angle measurement scope
CN110618465A (en) * 2018-06-04 2019-12-27 富士通株式会社 Article detection method and apparatus

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09257902A (en) * 1996-03-22 1997-10-03 Mitsubishi Electric Corp Bearing detecting device
JPH11183581A (en) * 1997-12-18 1999-07-09 Mitsubishi Electric Corp Method and device for detecting electric wave azimuth
JP2005003579A (en) * 2003-06-13 2005-01-06 Mitsubishi Electric Corp Angle measurement system and positioning system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09257902A (en) * 1996-03-22 1997-10-03 Mitsubishi Electric Corp Bearing detecting device
JPH11183581A (en) * 1997-12-18 1999-07-09 Mitsubishi Electric Corp Method and device for detecting electric wave azimuth
JP2005003579A (en) * 2003-06-13 2005-01-06 Mitsubishi Electric Corp Angle measurement system and positioning system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR101201900B1 (en) * 2011-02-01 2012-11-16 국방과학연구소 The method and apparatus for eleminationg path phase error generated at the direction finder
CN105445715A (en) * 2015-11-24 2016-03-30 大连楼兰科技股份有限公司 Method for improving radar angle measurement scope
CN110618465A (en) * 2018-06-04 2019-12-27 富士通株式会社 Article detection method and apparatus
CN110618465B (en) * 2018-06-04 2021-07-06 富士通株式会社 Article detection method and apparatus

Also Published As

Publication number Publication date
JP5278083B2 (en) 2013-09-04

Similar Documents

Publication Publication Date Title
US10539645B2 (en) Angle of arrival estimation
KR100826530B1 (en) Apparatus and method for computing location of a moving beacon using time difference of arrival and multi-frequencies
JP6778336B2 (en) RF signal arrival angle determination method and system
JP6797318B2 (en) Interferometer arrival time delay
KR100778309B1 (en) Apparatus and Method for computing location of a moving beacon using received signal strength and multi-frequencies
JP2017535788A (en) Method and apparatus for increasing angular resolution in an automotive radar system
US7961147B1 (en) Long baseline phase interferometer ambiguity resolution using frequency differences
JP5701083B2 (en) Radar device and method for calculating received power in the radar device
EP1818683B1 (en) Methods and systems for interferometric cross track phase calibration
JP2009168452A (en) Radar system
JP6324327B2 (en) Passive radar equipment
JP4901833B2 (en) Radar equipment
US11041953B2 (en) Object detecting device and sensor device
JP5278083B2 (en) Target orientation calculation device
Singh et al. Digital receiver-based electronic intelligence system configuration for the detection and identification of intrapulse modulated radar signals
Kalmykov et al. A FMCW—Interferometry approach for ultrasonic flow meters
RU2330304C1 (en) Phase direction-finder
KR101770097B1 (en) Interferometry based angle estimation apparatus using direct phase difference comparison and method therefore
JP2005189177A (en) Wind velocity vector calculation device
JP5208408B2 (en) Relative position estimation system
KR20200053222A (en) Radar apparatus and radar signal processing method for precise measurement of distance, angular velocity
JP5379312B2 (en) Distance measuring device
JP3269965B2 (en) Orientation detection device
Zhao et al. A high precision direction-finding method based on multi-baseline for target rescue
RU2324198C1 (en) Apparatus for object movement characteristics detection equipped with noise active interference protection

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20110118

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20130128

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20130205

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20130215

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20130312

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20130405

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20130423

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20130506

R151 Written notification of patent or utility model registration

Ref document number: 5278083

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250

R250 Receipt of annual fees

Free format text: JAPANESE INTERMEDIATE CODE: R250