JPH07174839A - Signal detecting method - Google Patents
Signal detecting methodInfo
- Publication number
- JPH07174839A JPH07174839A JP31769293A JP31769293A JPH07174839A JP H07174839 A JPH07174839 A JP H07174839A JP 31769293 A JP31769293 A JP 31769293A JP 31769293 A JP31769293 A JP 31769293A JP H07174839 A JPH07174839 A JP H07174839A
- Authority
- JP
- Japan
- Prior art keywords
- signal
- frequency
- detected
- signal strength
- estimated
- 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
Links
- 238000000034 method Methods 0.000 title claims description 20
- 238000009826 distribution Methods 0.000 claims abstract description 75
- 238000001514 detection method Methods 0.000 claims description 25
- 238000005070 sampling Methods 0.000 claims description 4
- 238000010606 normalization Methods 0.000 abstract description 15
- 238000012545 processing Methods 0.000 description 26
- 238000000605 extraction Methods 0.000 description 12
- 238000010586 diagram Methods 0.000 description 4
- 238000005259 measurement Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 239000000284 extract Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 238000010183 spectrum analysis Methods 0.000 description 2
- 238000004590 computer program Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
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- Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、レーダ或いはソーナ等
に用いられ、複数の方位に指向した各受波ビームに周波
数分析を行うことにより得られる入力信号強度及び周波
数空間上の分布に基づき、未知の狭帯域信号の到来を探
知する信号探知方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for a radar or a sonar, and is based on an input signal strength and a frequency space distribution obtained by performing frequency analysis on each received beam directed in a plurality of directions. The present invention relates to a signal detection method for detecting the arrival of an unknown narrow band signal.
【０００２】[0002]
【従来の技術】異なる方位に対する指向性を持つ複数の
受波ビームを用いて所定の連続した範囲の方位を監視
し、未知の被探知信号の到来方位及びその周波数を探知
する従来の信号探知方法について説明する。従来の信号
探知方法においては、少しずつ異なる方位を指向する複
数の受波ビームから被探知信号を含んだ受波信号を受信
する。各受波ビームに対してスペクトル分析が、それぞ
れ行われ、そのスペクトル分析により、各方位θにおけ
る受波信号の周波数ｆの成分に対する信号強度分布Ｘ
（ｆ，θ）が、それぞれ求められる。次に、各受波ビー
ム毎の信号強度分布Ｘ（ｆ，θ）に対して正規化が行わ
れる。方位θを固定して周波数ｆを変数とみたときの信
号強度分布Ｘ（ｆ，θ）の平均値をｍ（θ）、標準偏差
をσ（θ）とすると、信号強度分布Ｘ（ｆ，θ）は、
（１）式によって、平均値０、標準偏差１の確率分布に
従う相対信号強度分布Ｙ（ｆ，θ）に変換することがで
きる。この操作を、正規化と呼ぶ。 Ｙ（ｆ，θ）＝｛Ｘ（ｆ，θ）−ｍ（θ）｝／σ（θ） …（１） ただし、（１）式で用いられる平均値ｍ（θ）及び標準
偏差σ（θ）は、通常、信号強度分布中の各信号強度に
対応する周波数成分ｆの近傍の周波数領域のデータから
算出される。2. Description of the Related Art A conventional signal detecting method for monitoring an azimuth of an unknown detected signal and its frequency by monitoring azimuths in a predetermined continuous range by using a plurality of receiving beams having directivity for different azimuths. Will be described. In the conventional signal detection method, a received signal including a detected signal is received from a plurality of received beams that are directed in slightly different directions. Spectral analysis is performed on each received beam, and the signal intensity distribution X for the frequency f component of the received signal in each azimuth θ is obtained by the spectral analysis.
(F, θ) are obtained respectively. Next, the signal intensity distribution X (f, θ) for each received beam is normalized. When the average value of the signal intensity distribution X (f, θ) when the direction θ is fixed and the frequency f is regarded as a variable is m (θ) and the standard deviation is σ (θ), the signal intensity distribution X (f, θ). ) Is
According to the equation (1), it is possible to convert into a relative signal intensity distribution Y (f, θ) that follows a probability distribution with an average value of 0 and a standard deviation of 1. This operation is called normalization. Y (f, θ) = {X (f, θ) −m (θ)} / σ (θ) (1) However, the average value m (θ) and the standard deviation σ (θ) used in the equation (1). ) Is usually calculated from the data in the frequency domain near the frequency component f corresponding to each signal strength in the signal strength distribution.
【０００３】次に、従来の信号探知方法は、受波ビーム
毎の相対信号強度分布Ｙ（ｆ，θ）に対してピークを検
出する。ここで、ピークとは、相対信号強度が同じ受波
ビーム内の両隣の相対信号強度分布の周波数サンプルに
おける相対信号強度よりも大きく、かつ、両隣の受波ビ
ームの同じ周波数サンプルにおける相対信号強度よりも
大きくなる被探知信号推定用の周波数と方位の組の点
（ｆ0 ，θ0 ）のことである。点（ｆ0 ，θ0 ）に対す
る相対信号強度Ｙ（ｆ0 ，θ0 ）が、ピークになってお
り、しかもその相対信号強度Ｙ（ｆ0 ，θ0 ）が予め設
定された閾値Ｔを越えたならば、信号探知方法は、周波
数ｆ0 の狭帯域信号が到来したと判断し、その到来方位
θを、大旨θ0 であると判断する。最後に、従来の信号
探知方法は、正規化していない信号強度分布Ｘ（ｆ，
θ）の点（ｆ0 ，θ0 ）近辺のデータを用いて、精密な
方位θ1 を求める。これには、例えば、方位θ0 の近傍
の数点を用いて補間を行い極大点を求める方法が採用さ
れる。このようにして、被探知信号である周波数ｆ0 の
狭帯域信号が、方位θ1 から到来したと探知される。Next, the conventional signal detection method detects a peak in the relative signal intensity distribution Y (f, θ) for each received beam. Here, the peak is larger than the relative signal strength in the frequency samples of the relative signal strength distributions on both sides in the same receiving beam having the same relative signal strength, and more than the relative signal strength in the same frequency sample of the receiving beams on both sides. Is a point (f 0 , θ 0 ) of a pair of frequency and azimuth for estimating a detected signal. The relative signal intensity Y (f 0 , θ 0 ) with respect to the point (f 0 , θ 0 ) has a peak, and the relative signal intensity Y (f 0 , θ 0 ) exceeds the preset threshold T. If so, the signal detection method determines that a narrowband signal of frequency f 0 has arrived, and determines that the arrival direction θ is the outline θ 0 . Finally, the conventional signal detection method uses the unnormalized signal strength distribution X (f,
A precise azimuth θ 1 is obtained using the data near the point (f 0 , θ 0 ) of θ). For this purpose, for example, a method of interpolating using several points in the vicinity of the azimuth θ 0 to find the maximum point is adopted. In this way, it is detected that the narrowband signal having the frequency f 0 , which is the detected signal, comes from the azimuth θ 1 .
【０００４】図２は、従来の信号探知方法を説明するた
めの図である。図２を参照しつつ、従来の信号探知方法
を具体的に説明する。狭帯域信号を含んだ受波ビーム
１，２，３は、スペクトル分析されて例えば図２の
（Ａ）のような受波ビーム１，２，３毎の信号強度分布
となる。各信号強度分布は、正規化されて図２の（Ｂ）
の各相対信号強度分布にそれぞれ変換される。図２の例
では、受波ビーム２の相対信号強度分布の極大値が、両
隣の受波ビーム１，３の極大値に対して大きくなってい
る。また、その受波ビーム２の相対信号強度分布におい
て、周波数ｆの点が極大値となっている。即ち、受波ビ
ーム２の周波数ｆの点が、周波数に関しても、受波ビー
ムに関しても相対信号強度が極大を示し、その狭帯域信
号の到来を探知するための候補点となる。図２では、候
補点に対応する相対信号強度が閾値Ｔを越えているの
で、周波数ｆの狭帯域信号が、おおまかには受波ビーム
２の方位から到来していると推定される。次に、従来の
信号探知方法は、図２の（Ｃ）に示すように、被探知信
号の到来方位と推定された受波ビーム２とその周辺の受
波ビーム１，３の周波数ｆに対応するそれぞれの信号強
度に基づき、該到来方位を精測する。これには、例えば
放物線補間が用いられる。以上により、周波数ｆの信号
が、図２の（Ｃ）にθ1 で示した方位から到来している
という最終結果を得る。FIG. 2 is a diagram for explaining a conventional signal detecting method. The conventional signal detection method will be specifically described with reference to FIG. The received beams 1, 2, 3 including the narrow band signal are spectrally analyzed to have a signal intensity distribution for each of the received beams 1, 2, 3 as shown in FIG. Each signal intensity distribution is normalized and is shown in FIG.
Are converted into respective relative signal intensity distributions. In the example of FIG. 2, the maximum value of the relative signal intensity distribution of the reception beam 2 is larger than the maximum values of the reception beams 1 and 3 on both sides. Further, in the relative signal intensity distribution of the received beam 2, the point of frequency f has a maximum value. That is, the point of the frequency f of the received beam 2 is a candidate point for detecting the arrival of the narrow band signal, in which the relative signal strength shows the maximum both in the frequency and in the received beam. In FIG. 2, since the relative signal strength corresponding to the candidate point exceeds the threshold value T, it is estimated that the narrowband signal of the frequency f roughly comes from the azimuth of the received beam 2. Next, as shown in FIG. 2C, the conventional signal detection method corresponds to the frequency f of the received beam 2 estimated to be the arrival direction of the detected signal and the received beams 1 and 3 around it. The arrival direction is precisely measured based on the respective signal strengths. For this, for example, parabolic interpolation is used. From the above, the final result that the signal of the frequency f comes from the azimuth indicated by θ 1 in FIG.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、従来の
信号探知方法おいては、次のような課題があった。周囲
雑音が等方性でない場合、被探知信号の信号源の方位を
検出できない場合があった。即ち、正規化の際、受波ビ
ーム毎に各信号強度が拡大或いは縮小される率は、雑音
のレベルに左右される。そのため、方位によって雑音の
レベルが異なる場合、正規化の前後でピークの方位が大
きく変化することがあり、このピークの方位が変化する
ときには被探知信号の到来方位を求めることができなか
った。図３は、従来の信号探知方法の課題を説明する図
であり、図３を用いてその課題を具体的に説明する。図
３の（Ａ）は、４個の受波ビーム１，２，３，４に対す
る信号強度分布が示されている。図３の例では、未知の
狭帯域信号の信号源が受波ビーム２の方位に存在してい
るとする。また、周囲の雑音は、受波ビーム１で平均値
と標準偏差が大きく、それらの雑音は、受波ビーム４に
向かうにつれて次第に減少しているものとする。従来の
信号探知方法おいては、各信号強度分布を正規化して図
３の（Ｂ）ような相対信号強度分布を求めたうえで、ピ
ークを抽出する。このとき、受波ビーム３の相対信号強
度分布における各相対信号強度は、受波ビーム２の相対
信号強度よりも大きい率で拡大されるため、方位を示す
受波ビームに関する極大点は、受波ビーム３と判断され
てしまう。次に、正規化前の信号強度に基づいて、信号
の到来方向が算出される。ここで、受波ビーム３の信号
強度を中心とした放物線補間を用いると、正規化前の信
号強度では受波ビーム３が極大点になっていないので、
補間ができなくなる。或いは、強制的に放物線補間を実
施すると、図３の（Ｃ）にθ1 で示すように、真の到来
方位とは、異なる方位が検出される。本発明は前記従来
技術が持っていた課題として、周囲雑音に等方性がない
場合に被探知信号の到来方位を検出できない場合がある
点について解決をした信号探知方法を提供するものであ
る。However, the conventional signal detection method has the following problems. When the ambient noise is not isotropic, the direction of the signal source of the detected signal may not be detected. That is, at the time of normalization, the rate at which each signal strength is expanded or contracted for each received beam depends on the noise level. Therefore, when the noise level differs depending on the azimuth, the azimuth of the peak may change largely before and after the normalization, and when the azimuth of the peak changes, the arrival azimuth of the detected signal cannot be obtained. FIG. 3 is a diagram for explaining the problem of the conventional signal detection method, and the problem will be specifically described with reference to FIG. FIG. 3A shows the signal intensity distributions for the four received beams 1, 2, 3, and 4. In the example of FIG. 3, it is assumed that an unknown narrow-band signal source exists in the direction of the received beam 2. In addition, it is assumed that the ambient noise has a large average value and standard deviation in the received beam 1, and those noises gradually decrease toward the received beam 4. In the conventional signal detection method, each signal intensity distribution is normalized to obtain the relative signal intensity distribution as shown in FIG. 3B, and then the peak is extracted. At this time, since each relative signal intensity in the relative signal intensity distribution of the receiving beam 3 is expanded at a rate larger than the relative signal intensity of the receiving beam 2, the maximum point regarding the receiving beam indicating the azimuth is It will be judged as beam 3. Next, the arrival direction of the signal is calculated based on the signal strength before normalization. Here, when parabolic interpolation centered on the signal intensity of the received beam 3 is used, the received beam 3 is not the maximum point in the signal intensity before normalization,
Cannot interpolate. Alternatively, when the parabolic interpolation is forcibly performed, a direction different from the true arrival direction is detected, as indicated by θ 1 in FIG. SUMMARY OF THE INVENTION The present invention provides a signal detection method that solves the problem that the above-mentioned conventional technique has in that the arrival direction of a detected signal may not be detected when ambient noise is not isotropic.
【０００６】[0006]
【課題を解決するための手段】本発明は、前記課題を解
決するために、異なる方位に対する指向性を持つ複数の
受波ビームを用いて所定の連続した範囲の方位を監視
し、前記各受波ビームによってそれぞれ受波した受波信
号に対して周波数分析を行い各受波ビームの周波数に対
する信号強度分布をそれぞれ求め、前記各信号強度分布
に対して周波数領域毎の該各信号強度分布の平均値及び
標準偏差を用いて相対値へ変換し各受波ビーム毎の周波
数に対する相対信号強度分布をそれぞれ求め、前記各信
号強度分布と各相対信号強度分布に基づき前記受波信号
中の被探知信号の到来を探知すると共に該被探知信号の
周波数を検出し且つその被探知信号の到来方位を検出す
る信号探知方法において、次のような方法を講じてい
る。即ち、前記各相対信号強度分布に対して周波数でサ
ンプリングしたとき極大値の相対信号強度を示し、且つ
前記異なる方位に対する指向性を持つ複数の受波ビーム
間の前記信号強度分布に対して方位でサンプリングした
ときに同じ周波数における信号強度が極大値の信号強度
を示す推定周波数及び推定方位を抽出している。そし
て、前記推定周波数に対応する前記相対信号強度と所定
の閾値を比較して前記被探知信号の到来を探知し、該到
来を探知したときに該推定周波数を被探知信号の周波数
として検出し、且つ前記推定方位における該推定周波数
に対応した前記信号強度と前記複数の信号強度分布中の
該推定周波数に対応する前記信号強度とを用いて補間に
より前記到来方位を検出する。In order to solve the above-mentioned problems, the present invention monitors the azimuths in a predetermined continuous range by using a plurality of receiving beams having directivities for different azimuths, and receives each of the above-mentioned receiving beams. The received signal received by each wave beam is subjected to frequency analysis to obtain the signal strength distribution for the frequency of each received beam, and the average of each signal strength distribution for each frequency region is obtained for each signal strength distribution. The relative signal strength distribution for each frequency of each received beam is converted to a relative value using the value and standard deviation, and the detected signal in the received signal based on each signal strength distribution and each relative signal strength distribution. In the signal detecting method for detecting the arrival of the signal, detecting the frequency of the detected signal, and detecting the arrival direction of the detected signal, the following method is taken. That is, the relative signal strength of each of the relative signal strength distributions is shown as a maximum value when sampled at a frequency, and in the azimuth with respect to the signal strength distribution between the plurality of receiving beams having directivity for the different azimuths. The estimated frequency and the estimated azimuth indicating the signal intensity with the maximum signal intensity at the same frequency when sampling are extracted. Then, the relative signal strength corresponding to the estimated frequency is compared with a predetermined threshold value to detect the arrival of the detected signal, and when the arrival is detected, the estimated frequency is detected as the frequency of the detected signal, Further, the arrival direction is detected by interpolation using the signal intensity corresponding to the estimated frequency in the estimated direction and the signal intensity corresponding to the estimated frequency in the plurality of signal intensity distributions.
【０００７】[0007]
【作用】本発明によれば、以上のように信号探知方法を
構成したので、被探知信号を含んだ受波信号から、各受
波ビーム毎に周波数に対する信号強度分布が求められ、
この各信号強度分布から、各相対信号強度分布が求めら
れる。そして、各信号強度分布及び相対信号強度分布か
ら、各相対信号強度分布に対してサンプリングしたとき
極大値の相対信号強度を示し、且つ各信号強度分布に対
してサンプリングしたときに同じ周波数における信号強
度が極大値の信号強度を示す推定周波数及び推定方位
が、抽出される。本発明の信号探知方法では、その推定
周波数に対応する相対信号強度が閾値と比較され、被探
知信号の到来が探知される。被探知信号の到来が探知さ
れ場合、推定周波数が被探知信号の周波数として検出さ
れる。また、推定方位における該推定周波数に対応した
信号強度と複数の信号強度分布中の推定周波数に対応す
る信号強度とを用いた補間により、到来方位が検出され
る。従って、前記課題を解決できるのである。According to the present invention, since the signal detection method is configured as described above, the signal intensity distribution with respect to frequency is obtained for each received beam from the received signal including the detected signal,
From each signal intensity distribution, each relative signal intensity distribution is obtained. Then, from each signal strength distribution and the relative signal strength distribution, the relative signal strength of the maximum value is sampled for each relative signal strength distribution, and the signal strength at the same frequency is sampled for each signal strength distribution. An estimated frequency and an estimated azimuth indicating the maximum signal strength of is extracted. In the signal detection method of the present invention, the relative signal strength corresponding to the estimated frequency is compared with the threshold value to detect the arrival of the detected signal. When the arrival of the detected signal is detected, the estimated frequency is detected as the frequency of the detected signal. Further, the arrival direction is detected by interpolation using the signal strength corresponding to the estimated frequency in the estimated direction and the signal strength corresponding to the estimated frequency in the plurality of signal strength distributions. Therefore, the above problem can be solved.
【０００８】[0008]
【実施例】図１は、本発明の実施例の信号探知方法を示
すフローチャートである。この信号探知装置は、異なる
指向性を持つ複数の音響センサを有したセンサアレイを
用いて複数の受波ビームを形成し、未知の方位から到来
する未知の周波数の音波を探知する方法である。図１に
信号探知方法は、未知の音源１０からの信号をセンサア
レイ１１で受信する受信処理と、センサアレイ１１から
の信号を整相し、異なる方位に対して指向性を持つ複数
の受波ビームを生成する整相処理１２と、各受波ビーム
を分析して信号強度分布をそれぞれ求める周波数分析処
理１３とを行う。この信号探知方法は、また、各信号強
度分布を正規化し相対信号強度をそれぞれ求める正規化
処理１４と、各相対信号強度から周波数に関する極大点
を抽出する周波数極大点抽出処理１５と、各信号強度分
布から方位に関する極大点を抽出する方位極大点抽出処
理１６とを、施す。さらに、この信号探知方法は、周波
数極大点抽出処理１５及び方位極大点抽出処理１６の結
果から周波数と方位の双方に関して極大である音波到来
の推定点を抽出するＡＮＤ処理１７と、推定点に対応す
る相対信号強度と閾値Ｔとを比較する閾値判定処理１８
と、方位を精測する方位精測処理１９とを、施すように
している。1 is a flow chart showing a signal detecting method according to an embodiment of the present invention. This signal detection device is a method of forming a plurality of received beams using a sensor array having a plurality of acoustic sensors having different directivities and detecting a sound wave of an unknown frequency coming from an unknown direction. The signal detection method shown in FIG. 1 is a reception process in which a signal from an unknown sound source 10 is received by a sensor array 11, and a plurality of received waves having a directivity in different directions for phasing the signal from the sensor array 11. A phasing process 12 for generating a beam and a frequency analysis process 13 for analyzing each received beam to obtain a signal intensity distribution are performed. This signal detection method also includes a normalization process 14 for normalizing each signal intensity distribution to obtain a relative signal intensity, a frequency maximum point extracting process 15 for extracting a maximum point regarding frequency from each relative signal intensity, and each signal intensity. An azimuth maximum point extraction process 16 for extracting a maximum point regarding the azimuth from the distribution is performed. Further, this signal detection method corresponds to the AND processing 17 for extracting the estimated point of arrival of the sound wave having the maximum in both the frequency and the direction from the results of the frequency maximum point extraction processing 15 and the azimuth maximum point extraction processing 16, and the estimated point. Threshold determination processing 18 for comparing the relative signal strength with the threshold T
And the azimuth precise measurement processing 19 for precisely measuring the azimuth.
【０００９】次に、図１の信号探知方法による信号探知
動作を説明する。被探知信号を含む音波信号は、複数の
音響センサを有したセンサアレイ１１で受信される。整
相処理１２は、受信した音波信号から少しずつ異なる指
向性を持つ複数の受波ビームを生成し、周波数分析処理
１３は、それらを周波数分析して各受波ビーム毎の周波
数に対する信号強度分布をそれぞれ求める。即ち、この
周波数分析により、各方位θにおける入力信号の周波数
ｆの成分に対する信号強度分布Ｘ（ｆ，θ）が、それぞ
れ求められる。次に、正規化処理１４で、各受波ビーム
毎の信号強度分布Ｘ（ｆ，θ）が正規化される。方位θ
を固定して周波数ｆを変数とみたときの信号強度分布Ｘ
（ｆ，θ）の平均値をｍ（θ）、標準偏差をσ（θ）と
すると、信号強度分布Ｘ（ｆ，θ）は、従来と同様に
（１）式によって、平均値０、標準偏差１の確率分布に
従う相対信号強度分布Ｙ（ｆ，θ）に変換される。ここ
で、（１）式で用いられる平均値ｍ（θ）及び標準偏差
σ（θ）は、従来と同様に信号強度分布中の各信号強度
に対応する周波数成分ｆの近傍の周波数領域のデータか
ら算出されたものである。各相対信号強度分布が求めら
れた後、周波数極大点抽出処理１５は、各相対信号強度
分布Ｙ（ｆ，θ）において、相対信号強度がそれぞれ極
大値となっている周波数を抽出する。一方、方位極大点
抽出処理１６は、正規化前の各信号強度分布Ｘ（ｆ，
θ）から、同一サンプリング周波数における信号強度が
受波ビーム間で極大値となっている受波ビーム、即ち、
方位を抽出する。Next, the signal detection operation by the signal detection method of FIG. 1 will be described. The sound wave signal including the detected signal is received by the sensor array 11 having a plurality of acoustic sensors. The phasing process 12 generates a plurality of received beams having slightly different directivities from the received sound wave signals, and the frequency analysis process 13 frequency-analyzes them to obtain a signal intensity distribution with respect to the frequency of each received beam. Respectively. That is, by this frequency analysis, the signal intensity distribution X (f, θ) for the component of the frequency f of the input signal in each azimuth θ is obtained. Next, in the normalization processing 14, the signal intensity distribution X (f, θ) for each received beam is normalized. Azimuth θ
Signal strength distribution X when frequency f is regarded as a variable with fixed
Assuming that the average value of (f, θ) is m (θ) and the standard deviation is σ (θ), the signal intensity distribution X (f, θ) can be calculated by the equation (1) as in the conventional case, with the average value 0 and the standard value. It is converted into a relative signal intensity distribution Y (f, θ) according to the probability distribution of deviation 1. Here, the average value m (θ) and the standard deviation σ (θ) used in the equation (1) are the data in the frequency domain near the frequency component f corresponding to each signal intensity in the signal intensity distribution, as in the conventional case. It is calculated from. After each relative signal intensity distribution is obtained, the frequency maximum point extraction processing 15 extracts the frequency at which the relative signal intensity has the maximum value in each relative signal intensity distribution Y (f, θ). On the other hand, in the azimuth maximum point extraction processing 16, each signal strength distribution X (f,
θ), the received beam whose signal strength at the same sampling frequency has a maximum value between the received beams, that is,
Extract the azimuth.
【００１０】周波数極大点抽出処理１５及び方位極大点
抽出処理１６の結果を受けて、ＡＮＤ処理１７は、相対
信号強度が周波数に関して極大値で、且つ、正規化され
ていない信号強度分布が受波ビーム間で極大値となるよ
うな周波数及び方位の組の推定点（ｆ2 ，θ2 ）を抽出
する。即ち、各相対信号強度分布に対して周波数でサン
プリングしたとき極大値の相対信号強度を示し、且つ、
異なる指向性を有する複数の受波ビーム間の信号強度分
布に対して方位でサンプリングしたときに同じ周波数に
おける信号強度が極大値の信号強度を示す推定点
（ｆ2 ，θ2 ）が、抽出される。推定点（ｆ2 ，θ2 ）
は、被探知信号である音波信号の到来方位及びその周波
数の推定に用いられる。推定点（ｆ2 ，θ2 ）に対応す
る相対信号強度Ｙ（ｆ2 ，θ2 ）は、閾値判定処理１８
で閾値Ｔと比較され、Ｙ（ｆ2 ，θ2 ）≧Ｔのとき、被
探知信号が到来したと探知される。到来が探知された場
合、周波数ｆ2 が、被探知信号の周波数として検出され
る。方位精測処理１９は、被探知信号が到来したと判断
された場合、被探知信号の到来方向を検出する。この検
出には、正規化前の各信号強度分布Ｘ（ｆ，θ）のうち
推定方位に基づき選択された複数の信号強度分布Ｘ
（ｆ，θ）の極大値が、用いられる。例えば、３点の極
大値を用いた放物線補間によって、被探知信号の信号源
の方位θ3 が精測される。上記動作の結果、周波数ｆ2
及び方位θ3 の最終結果が得られる。In response to the results of the frequency maximum point extraction processing 15 and the azimuth maximum point extraction processing 16, the AND processing 17 receives the unnormalized signal strength distribution in which the relative signal strength is the maximum value with respect to the frequency. Estimated points (f 2 , θ 2 ) of a pair of frequency and azimuth having a maximum value between the beams are extracted. That is, the relative signal strength of the maximum value when sampled at a frequency for each relative signal strength distribution, and
Estimated points (f 2 , θ 2 ) at which the signal strength at the same frequency shows a maximum value when sampled in the direction with respect to the signal strength distribution between a plurality of received beams having different directivities are extracted. It Estimated point (f 2 , θ 2 )
Is used to estimate the arrival direction of the sound wave signal that is the detected signal and its frequency. The relative signal strength Y (f 2, θ 2) corresponding to the estimated point (f 2, θ 2), the threshold determination processing 18
Is compared with the threshold value T, and when Y (f 2 , θ 2 ) ≧ T, it is detected that the detected signal has arrived. When the arrival is detected, the frequency f 2 is detected as the frequency of the detected signal. When it is determined that the detected signal has arrived, the azimuth precise measurement processing 19 detects the arrival direction of the detected signal. For this detection, a plurality of signal intensity distributions X selected based on the estimated azimuth out of each signal intensity distribution X (f, θ) before normalization
The maximum of (f, θ) is used. For example, the direction θ 3 of the signal source of the detected signal is precisely measured by parabolic interpolation using the three local maximum values. As a result of the above operation, the frequency f 2
And the final result of the orientation θ 3 is obtained.
【００１１】以上のように、本実施例では、被探知信号
の音源１０の方位に対して各信号強度分布から推定方位
を抽出し、その推定方位に対応する信号強度分布と正規
化前の各信号強度分布Ｘ（ｆ，θ）とに基づいて被探知
信号の音源１０の方位が検出されるので、周囲の雑音に
等方性がない場合にも、信号の到来方向を確実に検出で
きる。なお、本発明は、上記実施例に限定されず種々の
変形が可能である。その変形例としては、例えば次のよ
うなものがある。 （１） 被探知信号は音波に限定されず、周波数と信号
強度を求め得るものであればよく、例えば電磁波等であ
ってもよい。従って本信号探知方法は、ソーナばかりで
なく、レーダ等に用いられてもよく、その場合について
も、本実施例と同様の効果を奏する。 （２） 図１に示された各処理は、個別に各処理を実施
する装置を用いてもよく、また、コンピュータのプログ
ラムを用いて実施してもよい。 （３） 周波数極大点抽出処理１５と方位極大点抽出処
理１６とで周波数と方位を独立に求め、ＡＮＤ処理１７
で、推定周波数及び推定方位の候補点を抽出している
が、先に推定周波数を求め、その周波数が方位に関する
候補点であるのか否かを調べる方法としてもよい。ま
た、逆に、推定方位を先に抽出し、その方位が周波数に
関する候補点であるか否かを調べる方法でも本実施例と
同様の効果を奏する。As described above, in this embodiment, the estimated azimuth is extracted from each signal intensity distribution with respect to the azimuth of the sound source 10 of the detected signal, and the signal intensity distribution corresponding to the estimated azimuth and each before normalization are extracted. Since the direction of the sound source 10 of the detected signal is detected based on the signal intensity distribution X (f, θ), the arrival direction of the signal can be reliably detected even when ambient noise is not isotropic. The present invention is not limited to the above embodiment, and various modifications can be made. The following are examples of such modifications. (1) The detected signal is not limited to a sound wave, and may be any signal as long as the frequency and signal strength can be obtained, and may be, for example, an electromagnetic wave. Therefore, the present signal detection method may be used not only for sonars but also for radars and the like, and in that case, the same effect as that of the present embodiment is obtained. (2) Each process shown in FIG. 1 may be performed by using an apparatus that individually executes each process, or by using a computer program. (3) The frequency maximum point extraction processing 15 and the azimuth maximum point extraction processing 16 independently obtain the frequency and the azimuth, and the AND processing 17
Although the candidate points for the estimated frequency and the estimated azimuth are extracted, the estimated frequency may be first obtained and a method of checking whether or not the frequency is a candidate point for the azimuth may be used. On the contrary, a method of extracting the estimated azimuth first and checking whether or not the azimuth is a candidate point regarding the frequency also has the same effect as that of the present embodiment.
【００１２】[0012]
【発明の効果】以上詳細に説明したように、本発明によ
れば、正規化前の信号強度分布から求められる方位と正
規化後の相対信号強度分布から求められる周波数とか
ら、推定周波数及び推定方位を抽出し、その推定周波数
に対応する相対信号強度が閾値と比較され、被探知信号
の到来が探知される。被探知信号の到来が探知され場
合、正規化前の信号強度分布から補間処理によって、被
探知信号の到来方位が検出される。そのため、周囲の雑
音に等方性がなく、信号強度分布の極大点が正規化の前
後で変化するような場合にも、信号の到来方向を確実に
検出できる。As described above in detail, according to the present invention, the estimated frequency and the estimated frequency are obtained from the azimuth obtained from the signal intensity distribution before normalization and the frequency obtained from the relative signal intensity distribution after normalization. The azimuth is extracted, the relative signal strength corresponding to the estimated frequency is compared with a threshold, and the arrival of the detected signal is detected. When the arrival of the detected signal is detected, the arrival direction of the detected signal is detected by interpolation processing from the signal strength distribution before normalization. Therefore, even if the surrounding noise is not isotropic and the maximum point of the signal strength distribution changes before and after the normalization, the arrival direction of the signal can be reliably detected.
【図１】本発明の実施例の信号探知方法を示すフローチ
ャートである。FIG. 1 is a flowchart showing a signal detection method according to an embodiment of the present invention.
【図２】従来の信号探知方法を説明するための図であ
る。FIG. 2 is a diagram for explaining a conventional signal detection method.
【図３】従来の信号探知方法の課題を説明する図であ
る。FIG. 3 is a diagram illustrating a problem of a conventional signal detection method.
１０ 未知の音源 １１ センサアレイ １２ 整相処理 １３ 周波数分析処理 １４ 正規化処理 １５ 周波数極大点抽出処理 １６ 方位極大点抽出処理 １７ ＡＮＤ処理（推定周波数及び推定方位抽出
処理） １８ 閾値判定処理 １９ 方位精測処理 Ｔ 閾値10 unknown sound source 11 sensor array 12 phasing processing 13 frequency analysis processing 14 normalization processing 15 frequency maximum point extraction processing 16 azimuth maximum point extraction processing 17 AND processing (estimated frequency and estimated azimuth extraction processing) 18 threshold determination processing 19 azimuth refinement Measurement processing T threshold
Claims (1)
受波ビームを用いて所定の連続した範囲の方位を監視
し、 前記各受波ビームによってそれぞれ受波した受波信号に
対して周波数分析を行い各受波ビームの周波数に対する
信号強度分布をそれぞれ求め、 前記各信号強度分布に対して周波数領域毎の該各信号強
度分布の平均値及び標準偏差を用いて相対値へ変換し各
受波ビーム毎の周波数に対する相対信号強度分布をそれ
ぞれ求め、 前記各信号強度分布と各相対信号強度分布に基づき前記
受波信号中の被探知信号の到来を探知すると共に該被探
知信号の周波数を検出し且つその被探知信号の到来方位
を検出する信号探知方法において、 前記各相対信号強度分布に対して周波数でサンプリング
したとき極大値の相対信号強度を示し、且つ前記異なる
方位に対する指向性を持つ複数の受波ビーム間の前記信
号強度分布に対して方位でサンプリングしたときに同じ
周波数における信号強度が極大値の信号強度を示す推定
周波数及び推定方位を抽出し、 前記推定周波数に対応する前記相対信号強度と所定の閾
値を比較して前記被探知信号の到来を探知し、該到来を
探知したときに該推定周波数を被探知信号の周波数とし
て検出し、且つ前記推定方位における該推定周波数に対
応した前記信号強度と前記複数の信号強度分布中の該推
定周波数に対応する前記信号強度とを用いて補間により
前記到来方位を検出することを特徴とした信号探知方
法。1. An azimuth in a predetermined continuous range is monitored by using a plurality of receiving beams having directivities for different azimuths, and frequency analysis is performed on the receiving signals received by the respective receiving beams. The signal intensity distribution for each frequency of each received beam is obtained, and the received beam is converted into a relative value by using the average value and standard deviation of each signal intensity distribution for each frequency domain for each signal intensity distribution. Obtaining the relative signal strength distribution for each frequency, detecting the arrival of the detected signal in the received signal based on the signal strength distribution and the relative signal strength distribution and detecting the frequency of the detected signal, and In the signal detection method for detecting the arrival direction of the detected signal, the relative signal strength of the maximum value is shown when sampling is performed at a frequency for each of the relative signal strength distributions, and Extracting the estimated frequency and the estimated azimuth indicating the signal strength of the maximum signal strength at the same frequency when sampling in the azimuth with respect to the signal strength distribution between a plurality of received beams having directivity for different azimuths, The arrival of the detected signal is detected by comparing the relative signal strength corresponding to the estimated frequency with a predetermined threshold value, and when the arrival is detected, the estimated frequency is detected as the frequency of the detected signal, and the estimation is performed. A signal detecting method, characterized in that the arrival direction is detected by interpolation using the signal intensity corresponding to the estimated frequency in the azimuth and the signal intensity corresponding to the estimated frequency in the plurality of signal intensity distributions.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31769293A JP2866292B2 (en) | 1993-12-17 | 1993-12-17 | Signal detection method |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP31769293A JP2866292B2 (en) | 1993-12-17 | 1993-12-17 | Signal detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07174839A true JPH07174839A (en) | 1995-07-14 |
| JP2866292B2 JP2866292B2 (en) | 1999-03-08 |
Family
ID=18090964
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP31769293A Expired - Lifetime JP2866292B2 (en) | 1993-12-17 | 1993-12-17 | Signal detection method |
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| Country | Link |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109975742A (en) * | 2017-12-28 | 2019-07-05 | 北京松果电子有限公司 | Detection method, detection device and the readable storage medium storing program for executing of the signal direction of the launch |
| JP2021128048A (en) * | 2020-02-13 | 2021-09-02 | 日本電気株式会社 | Sonar device, control method, and program |
-
1993
- 1993-12-17 JP JP31769293A patent/JP2866292B2/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109975742A (en) * | 2017-12-28 | 2019-07-05 | 北京松果电子有限公司 | Detection method, detection device and the readable storage medium storing program for executing of the signal direction of the launch |
| CN109975742B (en) * | 2017-12-28 | 2020-12-04 | 北京小米松果电子有限公司 | Signal emission direction detection method, detection device and readable storage medium |
| JP2021128048A (en) * | 2020-02-13 | 2021-09-02 | 日本電気株式会社 | Sonar device, control method, and program |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2866292B2 (en) | 1999-03-08 |
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