JP6851957B2 - Radar system and its radar signal processing method - Google Patents
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Description
本実施形態は、マルチスタティック方式のレーダシステム及びそのレーダ信号処理方法に関する。 The present embodiment relates to a multistatic radar system and a radar signal processing method thereof.
近時、レーダシステムにあっては、複数の送受信レーダ装置または複数の送信装置及び受信レーダ装置を互いに離間して配置し、各レーダ装置の観測結果により目標の位置を検出するマルチスタティック方式が開発されている。ただし、この種のレーダシステムでは、離隔したレーダ装置間の時刻同期が不十分な場合や距離精度が不十分な場合には、観測位置の誤差が大きくなる。また、送信装置が見通し外にある場合には、直接波を受信することができず、同期したマルチスタティック動作ができなくなってしまう。 Recently, in radar systems, a multi-static method has been developed in which multiple transmission / reception radar devices or multiple transmission devices and reception radar devices are arranged apart from each other and the target position is detected based on the observation results of each radar device. Has been done. However, in this type of radar system, if the time synchronization between the separated radar devices is insufficient or the distance accuracy is insufficient, the error of the observation position becomes large. Further, when the transmitting device is out of sight, the direct wave cannot be received, and the synchronized multi-static operation cannot be performed.
以上述べたように、従来のマルチスタティック方式によるレーダシステムでは、レーダ装置間の時刻同期ずれや中心周波数のずれ等の影響で、ビート周波数を精度よく観測できず、目標の位置を算出する上で距離精度が不十分であるという課題があった。 As described above, in the conventional multi-static radar system, the beat frequency cannot be observed accurately due to the influence of the time synchronization deviation between the radar devices and the deviation of the center frequency, and the target position is calculated. There was a problem that the distance accuracy was insufficient.
本実施形態は上記課題に鑑みなされたもので、レーダ装置間の時刻同期ずれや中心周波数のずれ等の影響を軽減してビート周波数の観測精度を向上させめことができ、目標の位置を算出する上で十分な距離精度が得られるレーダシステム及びそのレーダ信号処理方法を提供することを目的とする。 This embodiment has been made in view of the above problems, and can improve the observation accuracy of the beat frequency by reducing the influence of the time synchronization shift and the center frequency shift between the radar devices, and calculate the target position. It is an object of the present invention to provide a radar system capable of obtaining sufficient distance accuracy and a radar signal processing method thereof.
上記の課題を解決するために、本実施形態に係るレーダシステムは、送信装置と受信装置を備える。送信装置は、パルス圧縮用の送信パルスを通信期間とレンジ期間に分割し、通信期間のパルスに送信に関する通信情報を重畳して送信する。受信装置は、前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を前記レンジ期間の参照信号で圧縮し、信号対雑音電力比(SN)の高い反射点を用いて前記通信期間を抽出して相関処理することにより前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記レンジ期間のみまたは前記通信情報を用いて、前記通信期間及び前記レンジ期間のパルス全体で相関処理することによって目標の距離を出力する。 In order to solve the above problems, the radar system according to the present embodiment includes a transmitting device and a receiving device. The transmission device divides the transmission pulse for pulse compression into a communication period and a range period, and superimposes communication information on transmission on the pulse of the communication period and transmits the pulse. The receiving device receives the direct wave transmitted from the transmitting device or the reflected wave from the target, compresses the received signal with the reference signal during the range period, and obtains a reflection point having a high signal-to-noise power ratio (SN). The communication period is extracted by extracting the communication period and performing correlation processing, and the communication period is also obtained for other reflection points having a low signal-to-noise power ratio using only the range period or using the communication information. And the target distance is output by correlating the entire pulse during the range period.
以下、実施形態について、図面を参照して説明する。尚、各実施形態の説明において、同一部分には同一符号を付して示し、重複する説明を省略する。 Hereinafter, embodiments will be described with reference to the drawings. In the description of each embodiment, the same parts are designated by the same reference numerals, and duplicate description will be omitted.
(第1の実施形態)
図1乃至図11を参照して、第1の実施形態に係るレーダシステムを説明する。
(First Embodiment)
The radar system according to the first embodiment will be described with reference to FIGS. 1 to 11.
図1は本実施形態に係るレーダシステムの全体構成を示し、図2はその送信装置の構成を示し、図3はその受信装置の構成を示している。 FIG. 1 shows the overall configuration of the radar system according to the present embodiment, FIG. 2 shows the configuration of the transmitting device, and FIG. 3 shows the configuration of the receiving device.
図1に示すレーダシステムは、互いに同構成のN個の送信装置T1〜TN(図1ではN=3)と受信装置Rを備えるマルチスタティック方式を採用している。送信装置T1〜TNは、送信位置、送信周波数、送信タイミング等の通信情報をレーダ送信波に重畳し、目標Tに向けて送出する。一方、受信装置Rは、目標Tで反射されたレーダ送信波を受信して、目標Tの距離、角度、速度を観測するとともに、受信信号から通信情報を抽出し、その通信情報に基づいて目標の観測結果を補正する機能を有する。 The radar system shown in FIG. 1 employs a multi-static system including N transmitters T1 to TN (N = 3 in FIG. 1) and a receiver R having the same configuration as each other. The transmission devices T1 to TN superimpose communication information such as a transmission position, a transmission frequency, and a transmission timing on a radar transmission wave, and transmit the communication information toward the target T. On the other hand, the receiving device R receives the radar transmission wave reflected by the target T, observes the distance, angle, and speed of the target T, extracts communication information from the received signal, and targets based on the communication information. It has a function to correct the observation result of.
上記送信装置Ti(iは1〜Nのいずれか)は、図2に示すように、送信アンテナ装置T11、パルス変調器T12、周波数変換器T13、変調器T14、制御器T15、チャープ信号生成器T16、IFFT(Inverse Fast Fourier Transform)処理器T17及び通信変調信号生成器T18を備える。 As shown in FIG. 2, the transmitter Ti (i is any of 1 to N) includes a transmitter antenna device T11, a pulse modulator T12, a frequency converter T13, a modulator T14, a controller T15, and a chirp signal generator. It includes T16, an IFFT (Inverse Fast Fourier Transform) processor T17, and a communication modulation signal generator T18.
上記送信アンテナ装置T11は繰り返し供給される特定周波数の送信信号を指定方向に送出する。一方、通信変調信号生成器T18は、送信位置、送信周波数、送信タイミング、送信ビーム指向方向等を含む通信情報をビット(0,1)で表し、BPSK(非特許文献4参照)等により変調することで、通信変調信号を生成する。この通信変調信号は、IFFT処理器T17で逆フーリエ変換され、チャープ信号生成器T16で生成されるチャープ信号と共に制御器T15に送られる。制御器T15は、送信パルスを通信期間とレンジ期間に分割し、Nヒット(N>0)送信する。レンジ期間では、チャープ信号と通信変調信号について、パルス内制御によりパルス内のタイミングを制御し、変調器T14により送信パルスを生成し、周波数変換器T13で送信周波数に変換し、パルス変調器T12でパルスゲートによるパルス変調を施し、送信アンテナ装置T11で高出力増幅して送信する。 The transmitting antenna device T11 transmits a repeatedly supplied transmission signal of a specific frequency in a designated direction. On the other hand, the communication modulation signal generator T18 represents communication information including a transmission position, a transmission frequency, a transmission timing, a transmission beam directing direction, etc. in bits (0, 1) and modulates the communication information by BPSK (see Non-Patent Document 4) or the like. By doing so, a communication modulation signal is generated. This communication modulation signal is inverse Fourier transformed by the IFFT processor T17 and sent to the controller T15 together with the chirp signal generated by the chirp signal generator T16. The controller T15 divides the transmission pulse into a communication period and a range period, and transmits N hits (N> 0). In the range period, for the chirp signal and the communication modulation signal, the timing in the pulse is controlled by the intra-pulse control, the transmission pulse is generated by the modulator T14, converted into the transmission frequency by the frequency converter T13, and the pulse modulator T12. Pulse modulation is performed by a pulse gate, high output amplification is performed by the transmission antenna device T11, and transmission is performed.
受信装置R1は、図3に示すように、受信アンテナ装置R11、周波数変換器R12、AD(Analog-Digital)変換器R13、P2抽出器R14、相関処理パルス圧縮器R15、FFT(Slow-time)処理器R16、検出器R17、P3範囲選定器R18、P3抽出器R19、相関処理器(Slow-time)R20、復調器R21、P2+P3選定器R22、通信情報参照信号補正器R23、相関処理器R24、FFT(Slow-time)処理器R25、検出器R26、レンジ抽出器R27、出力処理器R28を備える。 As shown in FIG. 3, the receiving device R1 includes a receiving antenna device R11, a frequency converter R12, an AD (Analog-Digital) converter R13, a P2 extractor R14, a correlation processing pulse compressor R15, and an FFT (Slow-time). Processor R16, Detector R17, P3 Range Selector R18, P3 Extractor R19, Correlation Processor (Slow-time) R20, Demolator R21, P2 + P3 Selector R22, Communication Information Reference Signal Corrector R23, Correlation Processor R24 , FFT (Slow-time) processor R25, detector R26, range extractor R27, output processor R28.
すなわち、受信アンテナ装置R11で受信した信号は、周波数変換器R12でベースバンドに周波数変換され、AD変換器R13でデジタル信号に変換される。そして、P2抽出器R24により、レンジ期間のパルスP2の変調信号(チャープ等)が抽出され、相関処理器R15で相関処理(パルス圧縮)が施され、FFT処理器R16でパルス間(slow-time軸)のFFTが行われ、検出器R17にて、最大振幅のバンク信号を用いてCFAR(非特許文献4)等による検出が行われる。ここで、複数の検出点がある場合には、SN(信号対雑音電力比)の大きな信号を抽出することができるので、P3範囲選定器R18において、その時間軸を基準に通信期間P3の時間範囲を選定し、P3抽出器R19で通信期間P3を抽出する。 That is, the signal received by the receiving antenna device R11 is frequency-converted into a baseband by the frequency converter R12 and converted into a digital signal by the AD converter R13. Then, the P2 extractor R24 extracts the modulated signal (chirp, etc.) of the pulse P2 in the range period, the correlation processor R15 performs the correlation processing (pulse compression), and the FFT processor R16 performs the pulse interval (slow-time). The FFT of the axis) is performed, and the detector R17 performs detection by CFAR (Non-Patent Document 4) or the like using a bank signal having the maximum amplitude. Here, when there are a plurality of detection points, a signal having a large SN (signal-to-noise power ratio) can be extracted. Therefore, in the P3 range selector R18, the time of the communication period P3 is based on the time axis. A range is selected, and the communication period P3 is extracted by the P3 extractor R19.
次に、FFT処理器R20で、slow-time軸のFFT処理を施して高SNとした後、復調器R21で復調して通信情報を得る。通信情報の復調により、送信源の送信時刻、送信周波数、送信位置、通信期間の参照信号を取得できる。 Next, the FFT processor R20 performs FFT processing on the slow-time axis to obtain a high SN, and then the demodulator R21 demodulates to obtain communication information. By demodulating the communication information, it is possible to acquire a reference signal of the transmission time, transmission frequency, transmission position, and communication period of the transmission source.
また、P2+P3選定器R22において、AD変換出力から、レンジ期間P2と通信期間P3を選定し、通信情報参照信号補正器R23で通信期間P3の参照信号をレンジ期間P2に合わせ、送信処理器R24でP2+P3の相関処理を行い、FFT処理器R25でslow-time軸のFFTを行い、検出器R26でCFAR等により目標を検出し、レンジ抽出器R27でレンジを抽出し、出力処理器R28で所定の形式に変換して出力する。 Further, in the P2 + P3 selector R22, the range period P2 and the communication period P3 are selected from the AD conversion output, the reference signal of the communication period P3 is adjusted to the range period P2 by the communication information reference signal corrector R23, and the transmission processor R24 Correlation processing of P2 + P3 is performed, FFT of the slow-time axis is performed by the FFT processor R25, the target is detected by CFAR or the like by the detector R26, the range is extracted by the range extractor R27, and the predetermined range is extracted by the output processor R28. Convert to format and output.
本実施形態に係るレーダシステムでは、送信装置Tiと受信装置Rとの間が離隔しているため、送信位置、送信周波数、送信タイミング、送信ビーム指向方向等の情報を共有する必要がある。特に、送信位置が移動する場合には、リアルタイムに情報を共有する必要がある。送信装置と受信装置との間で見通しがある場合には、通信回線を確保することも可能であるが、見通し外の場合には、通信回線の確保は困難になる。この対策として、レーダ送信波に通信情報を重畳し、目標からの反射信号として復調すれば、通信が可能となる。これは、見通し内の場合でも、レーダの直接波を用いて通信できれば、通信回線を別に備える必要がなくなるので有用である。本実施形態では、パルス内で通信情報を重畳し、測距を行う手法について述べる。なお、測角処理については、ΣとΔビームによるモノパルス処理等の一般的な手法(非特許文献2)を用いることができるので、記述を割愛する。 In the radar system according to the present embodiment, since the transmission device Ti and the reception device R are separated from each other, it is necessary to share information such as the transmission position, the transmission frequency, the transmission timing, and the transmission beam direction direction. In particular, when the transmission position moves, it is necessary to share information in real time. It is possible to secure a communication line when there is a line of sight between the transmitting device and the receiving device, but it becomes difficult to secure a communication line when there is no line of sight. As a countermeasure, communication is possible by superimposing communication information on the radar transmission wave and demodulating it as a reflected signal from the target. This is useful because it is not necessary to separately provide a communication line if communication can be performed using the direct wave of the radar even in the line-of-sight. In this embodiment, a method of superimposing communication information in a pulse and performing distance measurement will be described. As for the angle measurement processing, a general method (Non-Patent Document 2) such as monopulse processing using Σ and Δ beams can be used, so the description is omitted.
上記構成によるレーダシステムにおいて、図4にマルチスタティックシステムの目標Tに対する送信ビーム及び受信ビームの様子を示し、図5に通信情報の送受信による目標位置同定の距離観測及びAZ,EL観測を説明するための座標系を示し、図6にレンジによるフィッティングを用いて目標の位置同定を行う様子を3次元座標系で示し、図7に送信波形を示し、図8に送信パルス内の通信変調信号を生成する様子を示し、図9に受信信号から通信期間を抽出して通信信号を復調する様子を示し、図10に受信信号のレンジ期間P2列の相関処理から通信期間を抽出して通信信号を復調する様子を示し、図10aに受信信号のレンジ期間P2+通信期間P3の相関処理から最大バンク信号の距離を抽出して通信信号を復調する様子を示す。なお、図4では、送信ビームをペンシルビームで表現しているが、送信ビームは無指向性を含むファンビームでもよい。 In the radar system having the above configuration, FIG. 4 shows the state of the transmission beam and the reception beam with respect to the target T of the multistatic system, and FIG. 5 is for explaining the distance observation and the AZ and EL observations of the target position identification by transmitting and receiving communication information. The coordinate system of is shown in FIG. 6, the state of performing the target position identification using the fitting by the range is shown in the three-dimensional coordinate system, the transmission waveform is shown in FIG. 7, and the communication modulation signal in the transmission pulse is generated in FIG. FIG. 9 shows how to extract the communication period from the received signal and demolish the communication signal, and FIG. 10 shows how to extract the communication period from the correlation processing of the range period P2 column of the received signal and demolish the communication signal. FIG. 10a shows a state in which the distance of the maximum bank signal is extracted from the correlation processing of the range period P2 + the communication period P3 of the received signal and the communication signal is demolished. Although the transmitted beam is represented by a pencil beam in FIG. 4, the transmitted beam may be a fan beam including omnidirectionality.
本実施形態では、受信装置Rで、目標Tの距離とAZ及びELの角度を観測すれば、図5に示すように、目標Tの位置を同定できる。または、図6に示すように、複数の送信〜受信の距離を観測すれば、距離によるフィッティングによって楕円球面の交点等から目標位置を同定できる。そこで、本実施形態は、送信装置及び受信装置間の時刻同期を高精度に調整する手法を提供する。 In the present embodiment, the position of the target T can be identified by observing the distance of the target T and the angles of AZ and EL with the receiving device R, as shown in FIG. Alternatively, as shown in FIG. 6, by observing a plurality of transmission-reception distances, the target position can be identified from the intersection of elliptical spheres or the like by fitting by distance. Therefore, the present embodiment provides a method for adjusting the time synchronization between the transmitting device and the receiving device with high accuracy.
送信装置Tiにおいて、送信信号は、図7に示すように、送信パルスが通信期間P3とレンジ期間P2に分割され、Nヒット(N>0)送信とする。通信情報としては、送信位置、送信周波数、送信タイミング、送信ビーム指向方向等をビット(0,1)で表し、図8に示すように、BPSK(非特許文献4)等により変換した信号を生成し(T18)、IFFTして(T17)、パルス内の通信変調信号を生成する。レンジ期間については、チャープ信号を生成し(T16)、通信変調信号とともに、パルス内制御によりパルス内のタイミングを制御し(T15)、通信期間P3とレンジ期間P2を含む送信パルスを生成し(T14)、送信周波数に周波数変換して(T13)、パルスゲートによるパルス変調を施して(T12)、高出力増幅し、目標に向けて送出する(T11)。 In the transmission device Ti, as shown in FIG. 7, the transmission pulse is divided into a communication period P3 and a range period P2, and N hit (N> 0) transmission is performed. As the communication information, the transmission position, transmission frequency, transmission timing, transmission beam direction, etc. are represented by bits (0, 1), and as shown in FIG. 8, a signal converted by BPSK (Non-Patent Document 4) or the like is generated. Then (T18) and IFFT (T17), the communication modulation signal in the pulse is generated. For the range period, a chirp signal is generated (T16), the timing in the pulse is controlled by intra-pulse control together with the communication modulation signal (T15), and a transmission pulse including the communication period P3 and the range period P2 is generated (T14). ), Frequency conversion to the transmission frequency (T13), pulse modulation by a pulse gate (T12), high output amplification, and transmission toward the target (T11).
受信装置Rにおいて、受信アンテナ装置R11で受信した信号は、ベースバンド信号に周波数変換され(R12)、AD変換される(R13)。AD変換された受信信号は。まず、図9に示すように、レンジ期間P2が抽出され(R14)、変調信号(チャープ等)による相関処理(パルス圧縮)が施され(R15)、図10に示すようにパルス間(slow-time軸)のFFTが行われ(R16)、最大振幅のバンク信号を用いてCFAR(非特許文献4)等による検出が行われる(R17)。ここで、複数の検出点がある場合には、SN(信号対雑音電力比)の大きな信号を抽出できるので、その時間軸を基準に通信期間P3の時間範囲を選定し(R18)、通信期間P3を抽出する(R19)。次に、slow-time軸で相関処理して高SNとした後(R20)、復調して通信情報を得る(R21)。 In the receiving device R, the signal received by the receiving antenna device R11 is frequency-converted into a baseband signal (R12) and AD-converted (R13). What is the AD-converted received signal? First, as shown in FIG. 9, the range period P2 is extracted (R14), correlation processing (pulse compression) is performed by a modulated signal (chirp or the like) (R15), and between pulses (slow-) as shown in FIG. The FFT of the time axis) is performed (R16), and the detection by CFAR (Non-Patent Document 4) or the like is performed using the bank signal having the maximum amplitude (R17). Here, when there are a plurality of detection points, a signal having a large SN (signal-to-noise power ratio) can be extracted. Therefore, the time range of the communication period P3 is selected based on the time axis (R18), and the communication period is selected. Extract P3 (R19). Next, after correlation processing is performed on the slow-time axis to obtain a high SN (R20), demodulation is performed to obtain communication information (R21).
ここで、通信情報を復調することにより、送信源の送信時刻を取得できれば、送信と受信の時刻同期を行うことができる。また、送信周波数がわかれば、ローカル信号の同調を行うことができ、正しいドップラを得ることができる。また、送信位置がわかれば、図5や図6のマルチスタティックによる目標の位置同定ができる。また、通信情報を復調できれば、通信期間の参照信号がわかるので、受信信号からレンジ期間P2と通信期間P3の選定を行い(R22)、通信期間P3の参照信号補正を行って、図11に示すように、レンジ期間P2を合わせた参照信号を生成し(R23)、P2+P3の相関処理を行い(R24)、slow-time軸のFFTを行い(R25)、CFAR等により目標を検出し(R26)、レンジを抽出し(R27)、出力する(R28)。 Here, if the transmission time of the transmission source can be obtained by demodulating the communication information, the transmission and reception times can be synchronized. Moreover, if the transmission frequency is known, the local signal can be tuned and the correct Doppler can be obtained. Further, if the transmission position is known, the target position can be identified by the multi-static of FIGS. 5 and 6. Further, if the communication information can be demolished, the reference signal of the communication period can be known. Therefore, the range period P2 and the communication period P3 are selected from the received signal (R22), the reference signal of the communication period P3 is corrected, and the reference signal is corrected and shown in FIG. As described above, a reference signal including the range period P2 is generated (R23), P2 + P3 correlation processing is performed (R24), slow-time axis FFT is performed (R25), and a target is detected by CFAR or the like (R26). , Extract the range (R27) and output (R28).
以下に、変調信号について定式化して説明する。まず、レンジ期間P2の変調信号は、チャープ変調とすると、次式で表現できる。 The modulated signal will be formulated and described below. First, the modulated signal of the range period P2 can be expressed by the following equation, assuming that it is a chirp modulation.
本実施形態では、チャープ変調で述べるが、符号変調方式等他の変調方式でもよい。 In the present embodiment, the term "chirp modulation" is used, but other modulation methods such as a code modulation method may be used.
次に通信期間P3の変調波形を考えると、例えばBPSK(非特許文献4)の場合は次式となる。 Next, considering the modulated waveform of the communication period P3, for example, in the case of BPSK (Non-Patent Document 4), the following equation is obtained.
これを用いて、パルス幅内の通信期間P3の変調を行う。 This is used to modulate the communication period P3 within the pulse width.
次に、図8に示すように、レンジ期間P2は(1)式、通信期間P3は(3)式の変調信号で変調を用いて変調する。通信期間P3の変調は、ほかの手法でもよい。 Next, as shown in FIG. 8, the range period P2 is modulated by the modulation signal of the equation (1), and the communication period P3 is modulated by the modulation signal of the equation (3). Modulation of the communication period P3 may be performed by another method.
次に、受信信号のうちレンジ期間の信号を圧縮する手法について定式化して説明する。これは、入力信号とパルス圧縮用信号の相関処理であり、これを周波数領域で行う場合について定式化すると次の通りである。 Next, a method of compressing the signal in the range period among the received signals will be formulated and described. This is a correlation process between the input signal and the pulse compression signal, and the case where this is performed in the frequency domain is formulated as follows.
まず、入力信号は、次式となる。 First, the input signal has the following equation.
次に、参照信号は次の通りである。 Next, the reference signal is as follows.
周波数軸の信号で乗算すると、次式となる。 Multiplying by the signal of the frequency axis gives the following equation.
パルス圧縮出力は逆FFTにより算出できる。 The pulse compression output can be calculated by inverse FFT.
以上により、図9に示すように、レンジ抽出ができる。レンジ抽出ができると、時間軸で通信期間P3の抽出ができるため、次に通信期間P3の復調を行う。このためには、通信期間P3の信号scom(t)のFFTを行う。 From the above, as shown in FIG. 9, range extraction can be performed. If the range can be extracted, the communication period P3 can be extracted on the time axis. Therefore, the communication period P3 is demodulated next. For this purpose, FFT of the signal scom (t) of the communication period P3 is performed.
通信期間P3を高精度に抽出し、その期間のみによる復調処理ができるため、通信復調の精度が高まることになる。この信号の位相情報を抽出することにより、ビットを抽出して復調できる。 Since the communication period P3 can be extracted with high accuracy and the demodulation process can be performed only during that period, the accuracy of communication demodulation is improved. By extracting the phase information of this signal, the bits can be extracted and demodulated.
なお、図9では、簡単のために1PRI分の処理について述べたが、Nヒットの複数PRIの場合には、図10に示すように、P2列の相関処理(R15)とslow-time軸のFFT(R16)を行い、ドップラ軸の最大バンク信号に対して、距離を抽出(R17)すれば、高いSNで通信期間P3を抽出でき、復調精度も高まる。 In FIG. 9, the processing for one PRI is described for the sake of simplicity, but in the case of multiple PRIs with N hits, as shown in FIG. 10, the correlation processing (R15) of the P2 column and the slow-time axis If FFT (R16) is performed and the distance is extracted (R17) from the maximum bank signal of the Doppler axis, the communication period P3 can be extracted with a high SN, and the demodulation accuracy is also improved.
次に、通信復調に用いた目標以外の目標のレンジングを行うことを検討する。この場合は、小目標も含まれるため、レンジングのための相関処理時には、通信期間P3+レンジ期間P2の相関処理を行う方がSNが高くなる。このため、参照信号を連結する。 Next, consider performing target range other than the target used for communication demodulation. In this case, since a small target is also included, the SN is higher when the correlation processing of the communication period P3 + the range period P2 is performed at the time of the correlation processing for the range. Therefore, the reference signals are connected.
通信期間P3の参照信号は、復調信号が既知となるため、(3)式のScomと同じである。これと、(5)式のレンジ期間の参照信号Srefを連結すればよい。 The reference signal of the communication period P3 is the same as the Scom of the equation (3) because the demodulated signal is known. This may be connected to the reference signal Sref in the range period of Eq. (5).
このScom_rを用いて相関処理を行う。 Correlation processing is performed using this Scom_r.
まず、入力信号は、次式となる。 First, the input signal has the following equation.
次に、参照信号は次の通りである。 Next, the reference signal is as follows.
周波数軸の信号で乗算すると、次式となる。 Multiplying by the signal of the frequency axis gives the following equation.
パルス圧縮出力は逆FFTにより算出できる。 The pulse compression output can be calculated by inverse FFT.
以上により、信号対雑音電力比の低い反射点についても、通信期間P3+レンジ期間P2全体のパルスを用いた相関処理を行い、Nヒットの複数PRIがある場合には、図11に示すようにslow-time軸のFFT(R25)を行い、CFAR等により検出(R26)した後、高いSNでレンジ抽出(R27)できる。本実施形態は、通信期間P3のパルスの受信期間を、レンジ期間P2のパルスの相関処理結果を用いて抽出し、高いSNで通信復調して送信装置Tと受信装置Rを同期同調するともに、通信期間P3を含めた相関処理により、目標Tの距離を高いSNで抽出することに特徴を有する。 As described above, even for reflection points with a low signal-to-noise power ratio, correlation processing is performed using the pulses of the entire communication period P3 + range period P2, and if there are multiple N-hit PRIs, slow as shown in FIG. After performing FFT (R25) on the -time axis and detecting (R26) by CFAR or the like, range extraction (R27) can be performed with a high SN. In this embodiment, the reception period of the pulse of the communication period P3 is extracted by using the correlation processing result of the pulse of the range period P2, the communication is demodulated at a high SN, and the transmission device T and the reception device R are synchronized and tuned. It is characterized in that the distance of the target T is extracted with a high SN by the correlation processing including the communication period P3.
なお、通信期間P3を含めずレンジ期間P2のみの相関処理で、目標Tが検出できれば、レンジ期間P2のみの相関処理によるレンジを出力してもよい。 If the target T can be detected by the correlation processing of only the range period P2 without including the communication period P3, the range by the correlation processing of only the range period P2 may be output.
以上により、図5に示すように、送信〜受信の距離と、(13)式で検出した信号の測角処理より、受信装置からみたAZ、EL角を観測できるのので、目標の位置を同定することができる。 From the above, as shown in FIG. 5, the AZ and EL angles seen from the receiving device can be observed from the transmission-reception distance and the angle measurement processing of the signal detected by the equation (13), so that the target position can be identified. can do.
また、図6に示すように送信装置を3台とすると、送信1〜受信、送信2〜受信、送信3〜受信までの各々の距離として、R1、R2、R3を得ることができる。この距離を用いて、図6に示すように、目標Tの位置(x、y、z)を算出する。この手法としては、R1の球面とR2及びR3の楕円球面の交点となる。その中で、受信装置Rにより観測したAZ角、EL角方向の3次元の位置を中心に、所定の範囲内を目標存在領域として、その中の交点を算出する。解で算出できない場合は、目標存在領域内の点を(x、y、z)の格子点に分割し、各々の点で次式の値が最小となる点(x、y、z)を算出する。
Further, when the number of transmission devices is three as shown in FIG. 6, R1, R2, and R3 can be obtained as the respective distances from
なお、受信装置に送受信機能がある場合には、送信装置は2台により、同様の方法での交線の中点を目標の3次元の観測位置として出力することができる。 If the receiving device has a transmitting / receiving function, the two transmitting devices can output the midpoint of the line of intersection as the target three-dimensional observation position in the same manner.
以上のように、第1の実施形態に係るレーダシステムでは、送信装置はパルス圧縮用の送信パルスτ(連続波含む)を通信期間P3とレンジ期間P2に分割し、通信期間のパルスに送信に関する通信情報を重畳して送信し、受信装置は送信装置から送信される直接波または目標からの反射波を受信し、その受信信号をレンジ期間の参照信号で圧縮して、SNの高い反射点を用いて、通信期間を抽出して相関処理することにより、通信情報(送信位置、送信時刻、送信周波数、送信ビーム指向方向等)を抽出し、信号対雑音電力比の低い他の反射点についても、レンジ期間のみか、または、通信情報を用いて、通信期間+レンジ期間のパルス全体で相関処理して、目標の距離を出力するようにしている。 As described above, in the radar system according to the first embodiment, the transmitting device divides the transmission pulse τ (including continuous wave) for pulse compression into the communication period P3 and the range period P2, and transmits the pulse in the communication period. The communication information is superimposed and transmitted, and the receiving device receives the direct wave transmitted from the transmitting device or the reflected wave from the target, and the received signal is compressed by the reference signal during the range period to obtain a high reflection point of the SN. By extracting the communication period and performing correlation processing, communication information (transmission position, transmission time, transmission frequency, transmission beam direction, etc.) is extracted, and other reflection points with a low signal-to-noise power ratio are also extracted. , Only in the range period, or by using the communication information, the target distance is output by performing the correlation processing for the entire pulse of the communication period + the range period.
上記の構成によれば、レンジ期間P2のパルスで通信期間P3を抽出し、復調して送信装置の位置、送信タイミング、送信周波数、送信ビーム指向方向等を通信情報から抽出することにより、送信装置と受信装置を同期同調し、補正した参照信号を用いて、通信期間P3、レンジ期間P2の長いパルス列で相関処理することで、高いSNで目標の距離を出力することができる。 According to the above configuration, the communication period P3 is extracted by the pulse of the range period P2, demodulated, and the position, transmission timing, transmission frequency, transmission beam directing direction, etc. of the transmission device are extracted from the communication information, thereby transmitting the transmission device. And the receiving device are synchronized and tuned, and the corrected reference signal is used to perform correlation processing with a long pulse train having a communication period P3 and a range period P2, so that a target distance can be output with a high SN.
(第2の実施形態)
第1の実施形態では、パルスを通信期間とレンジ期間に分割する手法について述べた。しかしながら、HPRF(High Pulse Repetition Frequency)のような短パルスでは、パルスを分割することが困難である。そこで、第2の実施形態では、パルス列を分割する手法に適用する例について述べる。
(Second embodiment)
In the first embodiment, a method of dividing a pulse into a communication period and a range period has been described. However, with a short pulse such as HPRF (High Pulse Repetition Frequency), it is difficult to divide the pulse. Therefore, in the second embodiment, an example applied to the method of dividing the pulse train will be described.
本実施形態に係るレーダシステムの送信装置Tiの構成を図12に、受信装置Rの構成を図13に示す。 The configuration of the transmitting device Ti of the radar system according to the present embodiment is shown in FIG. 12, and the configuration of the receiving device R is shown in FIG.
図12に示す送信装置Tiにおいて、図2と異なる点は、チャープ信号生成器T16に代わって基準信号生成器T20を用い、制御器T15に代わって時分割処理を行う制御器T19を用いたことにある。 In the transmitter Ti shown in FIG. 12, the difference from FIG. 2 is that the reference signal generator T20 is used instead of the chirp signal generator T16, and the controller T19 that performs time division processing is used instead of the controller T15. It is in.
また、図13に示す受信装置Rにおいて、図3と異なる点は、P2抽出器R14及び相関処理器(パルス圧縮)R15に代わってP1選定器R29を用い、検出器R17の後段にドップラ抽出器R30を追加し、P3抽出器R19に代わってドップラ参照信号補正器R31を用い、P2+P3選定器R22に代わってP2選定器R32、PRI列並べ替え器R33、ドップラ参照信号補正器R34を用いたことにある。 Further, in the receiving device R shown in FIG. 13, the difference from FIG. 3 is that the P1 selector R29 is used instead of the P2 extractor R14 and the correlation processor (pulse compression) R15, and the Doppler extractor is installed after the detector R17. R30 was added, the Doppler reference signal corrector R31 was used in place of the P3 extractor R19, and the P2 selector R32, PRI column sorter R33, and Doppler reference signal corrector R34 were used in place of the P2 + P3 selector R22. It is in.
図12に示す送信装置Tiにおいて、送信パルス列は、図14に示すように、ドップラ期間P1、レンジ期間P2、通信期間P3に分割される。このP1、P2、P3のそれぞれのパルス列は、PRF(Pulse Repetition Frequency)が同じでも異なっていてもよい。パルス送信変調は、図15に示すように、通信情報で符号変調したBPSK(非特許文献4)をFFTして、サンプリングした変調信号でパルス間を変調する。 In the transmission device Ti shown in FIG. 12, the transmission pulse train is divided into a Doppler period P1, a range period P2, and a communication period P3, as shown in FIG. The pulse trains of P1, P2, and P3 may have the same or different PRF (Pulse Repetition Frequency). In the pulse transmission modulation, as shown in FIG. 15, BPSK (Non-Patent Document 4) code-modulated with communication information is FFTed, and the pulses are modulated by the sampled modulation signal.
受信は、図16に示すように、ドップラ期間P1のPRF1のFFTにより、SNの高い目標で信号検出する。ドップラ抽出できれば、レンジ期間P2の参照信号を補正して、レンジ圧縮し、レンジ抽出を行う。レンジ抽出ができれば、通信期間P3を時間軸で抽出できるため、図17に示すように通信期間のパルス列P3のIFFTにより、復調し、通信情報を得る。通信情報として、送信位置、送信周波数、送信タイミング、送信ビーム指向方向等のマルチスタティックレーダとしての使い方は、第1の実施形態と同様である。 As shown in FIG. 16, the signal is detected at a high target of SN by the FFT of PRF1 in the Doppler period P1. If the Doppler can be extracted, the reference signal in the range period P2 is corrected, the range is compressed, and the range is extracted. If the range can be extracted, the communication period P3 can be extracted on the time axis. Therefore, as shown in FIG. 17, the communication period P3 is demodulated by the IFFT of the pulse train P3 to obtain the communication information. As communication information, the usage as a multi-static radar such as transmission position, transmission frequency, transmission timing, transmission beam directivity, etc. is the same as that of the first embodiment.
復調信号(通信情報)がわかれば、第1の実施形態と同様に通信期間P3の補正信号がわかる。レンジ抽出のためには、補正した参照信号と入力信号の相関処理を行えばよい。相関処理としては、slow-time軸×fast-time軸の全セルを用いた相関処理手法もあるが、SN(信号対雑音電力比)向上を図るために、レンジセル毎のslow-time軸の相関処理を行う。この場合、P1列、P2列、P3列のPRFが同じ場合には、図18に示すように、方式(1)ではP2列、方式(2)ではP1+P2列、または方式(3)ではP1+P2+P3列による相関処理がある。まず、パルス列の相関処理の一般形を定式化して説明する。 If the demodulated signal (communication information) is known, the correction signal of the communication period P3 can be known as in the first embodiment. For range extraction, the corrected reference signal and the input signal may be correlated. As the correlation processing, there is also a correlation processing method using all cells of the slow-time axis × fast-time axis, but in order to improve the SN (signal-to-noise power ratio), the correlation of the slow-time axis for each range cell Perform processing. In this case, when the PRFs of the P1 row, the P2 row, and the P3 row are the same, as shown in FIG. 18, the P2 row in the method (1), the P1 + P2 row in the method (2), or the P1 + P2 + P3 row in the method (3). There is correlation processing by. First, the general form of pulse train correlation processing will be formulated and described.
まず、入力信号は、次式となる。 First, the input signal has the following equation.
次に、参照信号は次の通りである。 Next, the reference signal is as follows.
周波数軸の信号で乗算すると、次式となる。 Multiplying by the signal of the frequency axis gives the following equation.
相関処理は逆FFTにより算出できる。 Correlation processing can be calculated by inverse FFT.
以上により、fast-time軸のレンジセル(レンジセル数Cellfast)毎でslow-time軸(セル数Cellslow)の相関処理出力が得られる。全体時間は、Cellfast×Cellslowのセル数で、1セルの時間はfast-time軸のサンプリング時間の時間である。この全体時間の中で図18に示すように、レンジを抽出することができる。 As described above, the correlation processing output of the slow-time axis (cellslow number of cells) can be obtained for each range cell (cellfast number of range cells) of the fast-time axis. The total time is the number of cells of Cellfast × Cellslow, and the time of one cell is the time of the sampling time on the fast-time axis. Ranges can be extracted during this total time, as shown in FIG.
次に、各方式(1)〜(3)は、(16)式の参照信号sref0(tslow)が異なるのみである。 Next, each method (1) to (3) differs only in the reference signal sref0 (tslow) of the method (16).
方式(1)のP2列のみの場合は、レンジ期間の変調信号をドップラにより補正した参照信号を用いる。 In the case of only the P2 column of the method (1), the reference signal obtained by correcting the modulated signal in the range period by Doppler is used.
方式(2)のP1+P2列の場合は、ドップラ期間+レンジ期間の補正を行う。 In the case of the P1 + P2 column of the method (2), the Doppler period + range period is corrected.
方式(3)のP1+P2+P3列の場合は、方式(2)にP1列を付加する。 In the case of the P1 + P2 + P3 column of the method (3), the P1 column is added to the method (2).
これらの参照信号を用いて、全体の相関処理を行う。これにより、信号対雑音電力比の低い反射点についても、高いSNで小目標を検出でき、距離と速度を出力できる。なお、P1列、P2列及びP3列のPRFにおいて、異なるPRFがある場合には、少なくともレンジ期間のP2列を含む同じPRFの信号列を用いて、レンジセル毎のslow-time軸における相関処理を行えばよい。 The entire correlation process is performed using these reference signals. As a result, even for a reflection point having a low signal-to-noise power ratio, a small target can be detected with a high SN, and the distance and speed can be output. If there are different PRFs in the PRFs of the P1 column, the P2 column, and the P3 column, the correlation processing on the slow-time axis for each range cell is performed using the signal sequence of the same PRF including the P2 column of at least the range period. Just do it.
以上述べたように、本実施形態では、通信期間のパルスの受信期間を、ドップラ期間とレンジ期間のパルスの相関処理結果を用いて抽出し、高いSNで通信復調して送信装置と受信装置を同期同調するともに、信号対雑音電力比の低い他の反射点についても、通信期間、ドップラ期間、レンジ期間を含めた相関処理により、目標の距離を高いSNで抽出することに特徴を有する。 As described above, in the present embodiment, the reception period of the pulse of the communication period is extracted by using the correlation processing result of the pulse of the Doppler period and the range period, and the communication is demodulated with a high SN to obtain the transmitting device and the receiving device. It is characterized in that other reflection points having a low signal-to-noise power ratio are also synchronized and tuned, and the target distance is extracted with a high SN by correlation processing including a communication period, a Doppler period, and a range period.
すなわち、第2の実施形態に係るレーダシステムでは、送信装置は、パルスを繰り返すレーダのパルス列を通信期間P3とドップラ期間P1とレンジ期間P2に時分割し、通信期間のパルスに送信に関する通信情報を重畳して送信し、受信装置は送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を、ドップラ期間P1のFFT結果のうち、SN比の高い反射点を用いてレンジ期間の参照信号を補正し、補正した参照信号によりレンジ期間P2を相関処理してレンジを抽出し、通信期間P3の受信信号を抽出してドップラで補正した参照信号により相関処理することによって通信情報(送信位置、送信時刻、送信周波数、送信ビーム指向方向等)を抽出する。信号対雑音電力比の低い他の反射点についても、通信期間P3は、通信情報とドップラを用いて参照信号を補正し、レンジ期間P2はドップラを用いて参照信号を補正し、通信期間P3、ドップラ期間P1、レンジ期間P2のうち、少なくともレンジ期間P2を含むパルス列で用いて相関処理して、目標の距離を出力する。 That is, in the radar system according to the second embodiment, the transmitting device time-divides the pulse train of the radar that repeats the pulse into the communication period P3, the Doppler period P1, and the range period P2, and transmits the communication information related to the transmission to the pulse of the communication period. The receiver receives the direct wave transmitted from the transmitter or the reflected wave from the target, and transmits the received signal by using the reflection point having a high SN ratio in the FFT result of the Doppler period P1. Communication is performed by correcting the reference signal in the range period, correlating the range period P2 with the corrected reference signal to extract the range, extracting the received signal in the communication period P3, and correlating with the reference signal corrected by the Doppler. Information (transmission position, transmission time, transmission frequency, transmission beam directing direction, etc.) is extracted. For other reflection points with a low signal-to-noise power ratio, the communication period P3 corrects the reference signal using the communication information and the Doppler, and the range period P2 corrects the reference signal using the Doppler, and the communication period P3, Of the Doppler period P1 and the range period P2, the pulse train including at least the range period P2 is used for correlation processing to output the target distance.
上記の構成によれば、ドップラ期間P1とレンジ期間P2のパルス列で通信期間P3を抽出し、復調して送信装置の位置、送信タイミング、送信周波数を通信情報から抽出することにより、送信装置と受信装置を同期同調し、補正した参照信号を用いて、通信期間P3、ドップラ期間P1、レンジ期間P2の長いパルス列で相関処理することで、高いSNで目標の距離を出力できる。 According to the above configuration, the communication period P3 is extracted from the pulse trains of the Doppler period P1 and the range period P2, demodulated, and the position, transmission timing, and transmission frequency of the transmission device are extracted from the communication information to obtain the transmission device and reception. The target distance can be output with a high SN by synchronizing the devices in synchronization and using the corrected reference signal to perform correlation processing with a long pulse train having a communication period P3, a Doppler period P1, and a range period P2.
(第3の実施形態)
第2の実施形態では、パルス列をドップラ期間、通信期間及びレンジ期間に分割する手法について述べた。この場合、時分割であるため、パルス列が長くなり、観測時間が長くなる。そこで、第3の実施形態では、これを避けるために、P1、P2、P3列を異なるPRFとして、同時送信する手法について述べる。
(Third Embodiment)
In the second embodiment, a method of dividing the pulse train into a Doppler period, a communication period, and a range period has been described. In this case, since it is time-divisioned, the pulse train becomes long and the observation time becomes long. Therefore, in the third embodiment, in order to avoid this, a method of simultaneously transmitting the P1, P2, and P3 columns as different PRFs will be described.
本実施形態に係るレーダシステムの送信装置Tiの構成を図19に、受信装置Rの構成を図20に示す。 FIG. 19 shows the configuration of the transmitting device Ti of the radar system according to the present embodiment, and FIG. 20 shows the configuration of the receiving device R.
図19に示す送信装置Tiにおいて、図12と異なる点は、時分割処理を行う制御器T19に代わって統合処理を行う制御器T21を用いたことにある。 The transmission device Ti shown in FIG. 19 differs from FIG. 12 in that the controller T21 that performs integrated processing is used instead of the controller T19 that performs time division processing.
また、図20に示す受信装置Rにおいて、図13と異なる点は、通信情報参照信号補正器R23を削除したことにある。 Further, in the receiving device R shown in FIG. 20, the difference from FIG. 13 is that the communication information reference signal corrector R23 is deleted.
図19に示す送信装置Tiにおいて、送信パルス列は、図21に示すように、通信期間P3、ドップラ期間P1、レンジ期間P2があり、これを同時に送信するように合成する(T21)。送信変調は、図22に示すように、通信情報で符号変調したBPSK(非特許文献4)をFFTして、サンプリングした変調信号でパルス間を変調する。 In the transmission device Ti shown in FIG. 19, as shown in FIG. 21, the transmission pulse train has a communication period P3, a Doppler period P1, and a range period P2, and is synthesized so as to transmit these at the same time (T21). In the transmission modulation, as shown in FIG. 22, BPSK (Non-Patent Document 4) code-modulated with communication information is FFTed, and the pulses are modulated by the sampled modulation signal.
図20に示す受信装置Rでは、図23に示すように、各信号列P1、P2、P3のPRFが異なる場合は、PRFを用いて信号を分離できる。また、通信期間P3とドップラ期間P1のPRFが同じ場合は、図24に示すように、P1+P3とP2の2通りに分離してもよい。また、通信期間P3とレンジ期間P2のPRFが同じ場合は、P1とP2+P3の2通りに分離してもよい。 In the receiving device R shown in FIG. 20, as shown in FIG. 23, when the PRFs of the signal sequences P1, P2, and P3 are different, the signals can be separated by using the PRFs. When the PRF of the communication period P3 and the Doppler period P1 are the same, they may be separated into two types, P1 + P3 and P2, as shown in FIG. 24. Further, when the PRFs of the communication period P3 and the range period P2 are the same, they may be separated into two types, P1 and P2 + P3.
分離した信号列を用いて、図25に示すように、ドップラ期間P1のPRF1のFFTにより、SNの高い目標で信号検出する。P1+P3の場合は、通信期間は通信変調信号によりパルス間で位相が異なるため加算されないが、ドップラ期間を長くすれば、高いSNでドップラを抽出できる。ドップラ抽出ができれば、レンジ期間の参照信号を補正して、レンジ圧縮し、レンジ抽出を行う、レンジ抽出ができれば、時間軸で、通信期間P3を時間軸で抽出できるため、通信期間のパルス列P3のIFFTにより、復調し、通信情報を得る。通信情報として、送信位置、送信周波数、送信タイミング等のマルチスタティックレーダとしての使い方は、第1の実施形態と同様である。 Using the separated signal sequences, as shown in FIG. 25, the signal is detected at a high target of SN by the FFT of PRF1 in the Doppler period P1. In the case of P1 + P3, the communication period is not added because the phases differ between the pulses due to the communication modulation signal, but if the Doppler period is lengthened, the Doppler can be extracted with a high SN. If Doppler extraction is possible, the reference signal of the range period is corrected, range compression is performed, and range extraction is performed. If range extraction is possible, the communication period P3 can be extracted on the time axis. It is demodulated by IFFT and communication information is obtained. As communication information, the usage as a multi-static radar such as transmission position, transmission frequency, transmission timing, etc. is the same as that of the first embodiment.
次に、レンジ抽出のためには、補正した参照信号と入力信号の相関処理を行えばよい。この場合、第2の実施形態と同様に、レンジセル毎にslow-time軸で相関処理を行うためには、同じPRF列が必要である。このため、図26に示すように、P2列のみを用いて相関処理を行う。なお、通信期間+レンジ期間を同じPRFとしたP2+P3の場合は、信号対雑音電力比の低い他の反射点についても、通信情報を復調した信号とドップラ期間のドップラ信号を用いて補正した通信期間P3の参照信号(第1の参照信号)と、ドップラ信号により補正したレンジ期間P2の参照信号(第2の参照信号)とを合わせて全体の参照信号として、P2+P3の相関処理を行えばよい。 Next, for range extraction, the corrected reference signal and the input signal may be correlated. In this case, as in the second embodiment, the same PRF column is required in order to perform the correlation processing on the slow-time axis for each range cell. Therefore, as shown in FIG. 26, the correlation processing is performed using only the P2 column. In the case of P2 + P3 in which the communication period + range period are the same PRF, the communication period corrected by using the signal obtained by demodulating the communication information and the Doppler signal of the Doppler period also for other reflection points having a low signal-to-noise power ratio. The P2 + P3 correlation processing may be performed by combining the reference signal of P3 (first reference signal) and the reference signal of the range period P2 corrected by the Doppler signal (second reference signal) as the entire reference signal.
これらの参照信号のドップラによる補正を含めた生成方法は、各パルス列の時間軸が図23の上図であり、時分割パルス列である第2の実施形態(図14)と異なる。このため、図23に合わせたパルス列の時間軸にする必要がある以外は、第2の実施形態と同様であるため、ここではその説明を割愛する。これらの参照信号を用いて、全体の相関処理を行う。これにより、高いSNで小目標を検出でき、距離と速度を出力できる。 The generation method including the correction of these reference signals by Doppler is different from the second embodiment (FIG. 14) in which the time axis of each pulse train is the upper figure of FIG. 23 and is a time-division pulse train. Therefore, it is the same as the second embodiment except that it is necessary to set the time axis of the pulse train according to FIG. 23, and the description thereof is omitted here. The entire correlation process is performed using these reference signals. As a result, a small target can be detected with a high SN, and the distance and speed can be output.
以上述べたように、本実施形態では、通信期間のパルスの受信期間を、ドップラ期間とレンジ期間のパルスの相関処理結果を用いて抽出し、高いSNで通信復調して送信装置と受信装置を同期同調するともに、信号対雑音電力比の低い他の反射点についても、通信期間、ドップラ期間、レンジ期間を含めた相関処理により、目標の距離を高いSNで抽出することに特徴を有する。 As described above, in the present embodiment, the reception period of the pulse of the communication period is extracted by using the correlation processing result of the pulse of the Doppler period and the range period, and the communication is demodulated with a high SN to obtain the transmitting device and the receiving device. It is characterized in that other reflection points having a low signal-to-noise power ratio are also synchronized and tuned, and the target distance is extracted with a high SN by correlation processing including a communication period, a Doppler period, and a range period.
すなわち、本実施形態に係るレーダシステムでは、送信装置は、パルスを繰り返すレーダのパルス列を通信期間P3とドップラ期間P1とレンジ期間P2の3通り(P3,P1,P2)、または通信期間P3及びドップラ期間P1とレンジ期間P2の2通り(P3+P1,P2)、またはドップラ期間P1と通信期間P3及びレンジ期間P2の2通り(P1,P3+P2)のPRFのパルス列とし、通信期間のパルスに送信に関する通信情報を重畳して、通信期間P3、ドップラ期間P1、レンジ期間P2のパルス列を混合して送信し、受信装置は送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を、ドップラ期間P1のFFT結果のうち、SNの高い反射点のドップラを用いてレンジ期間P2の参照信号を補正し、補正した参照信号によりレンジ期間P2を相関処理してレンジを抽出し、通信期間P3の受信信号を抽出して、ドップラで補正した参照信号で相関処理することによって通信情報(送信位置、送信時刻、送信周波数、送信ビーム指向方向等)を抽出し、信号対雑音電力比の低い他の反射点についても、レンジ期間P2において参照信号をドップラで補正したパルス列を用いて相関処理して、目標の距離を出力する。 That is, in the radar system according to the present embodiment, the transmitting device sets the pulse train of the radar that repeats the pulse in three ways (P3, P1, P2) of the communication period P3, the Doppler period P1 and the range period P2, or the communication period P3 and the Doppler. Two types of PRF (P3 + P1, P2) of period P1 and range period P2, or two types of PRF (P1, P3 + P2) of Doppler period P1 and communication period P3 and range period P2, and communication information related to transmission in the pulse of communication period. Is superposed, and the pulse trains of the communication period P3, the Doppler period P1 and the range period P2 are mixed and transmitted, and the receiving device receives the direct wave transmitted from the transmitting device or the reflected wave from the target and transmits the received signal. Of the FFT results of the Doppler period P1, the reference signal of the range period P2 is corrected by using the Doppler of the reflection point with high SN, the range period P2 is correlated with the corrected reference signal to extract the range, and the communication period is communicated. Communication information (transmission position, transmission time, transmission frequency, transmission beam direction, etc.) is extracted by extracting the received signal of P3 and correlating with the reference signal corrected by Doppler, and the signal-to-noise power ratio is low. The other reflection points are also subjected to correlation processing using a pulse train obtained by correcting the reference signal with a Doppler during the range period P2, and the target distance is output.
このように、本実施形態によれば、3通りのPRFのパルス列を混合して同時に送信することで、時分割の場合に比べて送信時間を短縮化するとともに、LPI(Low Probability of intercept)性も高まり、ドップラ期間P1とレンジ期間P2のパルス列で通信期間を抽出し、復調して送信装置の位置、送信タイミング、送信周波数、送信ビーム指向方向等を通信情報から抽出することにより、送信装置と受信装置を同期同調することができる。 As described above, according to the present embodiment, by mixing the pulse trains of three types of PRF and transmitting them at the same time, the transmission time is shortened as compared with the case of time division, and the LPI (Low Probability of intercept) property is achieved. By extracting the communication period from the pulse trains of the Doppler period P1 and the range period P2, demodulating it, and extracting the position, transmission timing, transmission frequency, transmission beam direction, etc. of the transmission device from the communication information, the transmission device and The receiving device can be synchronized and tuned.
なお、本実施形態は上記実施形態そのままに限定されるものではなく、実施段階ではその要旨を逸脱しない範囲で構成要素を変形して具体化できる。また、上記実施形態に開示されている複数の構成要素の適宜な組み合わせにより、種々の発明を形成できる。例えば、実施形態に示される全構成要素から幾つかの構成要素を削除してもよい。更に、異なる実施形態にわたる構成要素を適宜組み合わせてもよい。 It should be noted that the present embodiment is not limited to the above embodiment as it is, and at the implementation stage, the components can be modified and embodied within a range that does not deviate from the gist thereof. In addition, various inventions can be formed by an appropriate combination of the plurality of components disclosed in the above-described embodiment. For example, some components may be removed from all the components shown in the embodiments. Furthermore, components over different embodiments may be combined as appropriate.
T1〜TN…送信装置、R…受信装置、T…目標、
T11…送信アンテナ装置、T12…パルス変調器、T13…周波数変換器、T14…変調器、T15…制御器、T16…チャープ信号生成器、T17…IFFT(Inverse Fast Fourier Transform)処理器、T18…通信変調信号生成器、T19…制御器、T20…基準信号生成器、T21…制御器、
R11…受信アンテナ装置、R12…周波数変換器、R13…AD(Analog-Digital)変換器、R14…P2抽出器、R15…相関処理パルス圧縮器、R16…FFT(Slow-time)処理器、R17…検出器、R18…P3範囲選定器、R19…P3抽出器、R20…相関処理器(Slow-time)、R21…復調器、R22…P2+P3選定器、R23…通信情報参照信号補正器、R24…相関処理器、R25…FFT(Slow-time)処理器、R26…検出器、R27…レンジ抽出器、R28…出力処理器、R29…P1選定器、R30…ドップラ抽出器、R31…ドップラ参照信号補正器、R32…P2選定器、R33…PRI列並べ替え器、R34…ドップラ参照信号補正器。
T1 to TN ... Transmitter, R ... Receiver, T ... Target,
T11 ... Transmit antenna device, T12 ... Pulse modulator, T13 ... Frequency converter, T14 ... Modulator, T15 ... Controller, T16 ... Chirp signal generator, T17 ... IFFT (Inverse Fast Fourier Transform) processor, T18 ... Communication Modulation signal generator, T19 ... controller, T20 ... reference signal generator, T21 ... controller,
R11 ... Receiving antenna device, R12 ... Frequency converter, R13 ... AD (Analog-Digital) converter, R14 ... P2 extractor, R15 ... Correlation processing pulse compressor, R16 ... FFT (Slow-time) processor, R17 ... Detector, R18 ... P3 range selector, R19 ... P3 extractor, R20 ... Correlation processor (Slow-time), R21 ... Demodigator, R22 ... P2 + P3 selector, R23 ... Communication information reference signal corrector, R24 ... Correlation Processor, R25 ... FFT (Slow-time) processor, R26 ... Detector, R27 ... Range extractor, R28 ... Output processor, R29 ... P1 selector, R30 ... Doppler extractor, R31 ... Doppler reference signal corrector , R32 ... P2 selector, R33 ... PRI column sorter, R34 ... Doppler reference signal corrector.
Claims (8)
前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を前記レンジ期間の参照信号で圧縮し、信号対雑音電力比(SN)の高い反射点を用いて前記通信期間を抽出して相関処理することにより前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記レンジ期間のみまたは前記通信情報を用いて、前記通信期間及び前記レンジ期間のパルス全体で相関処理することによって目標の距離を出力する受信装置と
を具備するレーダシステム。 A transmission device that divides a transmission pulse for pulse compression into a communication period and a range period, and superimposes communication information on transmission on the pulse of the communication period and transmits it.
The direct wave transmitted from the transmitter or the reflected wave from the target is received, the received signal is compressed by the reference signal during the range period, and the communication is performed using the reflection point having a high signal-to-noise ratio (SN). The communication information is extracted by extracting the period and performing correlation processing, and the communication period and the range period are also used for other reflection points having a low signal-to-noise power ratio using only the range period or the communication information. A radar system including a receiver that outputs a target distance by correlating the entire pulse of.
前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を前記ドップラ期間のFFT結果のうち、信号対雑音電力比(SN)の高い反射点のドップラを用いて前記レンジ期間の参照信号を補正し、補正した参照信号により前記レンジ期間を相関処理してレンジを抽出し、通信期間の受信期間を抽出して前記ドップラで補正した参照信号により相関処理することによって前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記通信期間は前記通信情報と前記ドップラを用いて参照信号を補正し、前記レンジ期間は前記ドップラを用いて参照信号を補正し、前記通信期間、前記ドップラ期間、前記レンジ期間のうち、少なくとも前記レンジ期間を含むパルス列で用いて相関処理して目標の距離を出力する受信装置と
を具備するレーダシステム。 A transmitter that time-divides the pulse train of the radar that repeats the pulse into a communication period, a Doppler period, and a range period, and superimposes communication information on transmission on the pulse of the communication period and transmits it.
The direct wave transmitted from the transmitter or the reflected wave from the target is received, and the received signal is used as the Doppler at the reflection point having a high signal-to-noise power ratio (SN) in the FFT result of the Doppler period. The reference signal of the range period is corrected, the range period is correlated with the corrected reference signal to extract the range, the reception period of the communication period is extracted, and the reference signal corrected by the Doppler is used for correlation processing. The communication information is extracted, and for other reflection points having a low signal-to-noise power ratio, the reference signal is corrected by using the communication information and the Doppler during the communication period, and the reference signal is corrected by using the Doppler during the range period. A radar system including a receiving device for outputting a target distance by performing correlation processing using a pulse train including at least the range period among the communication period, the Doppler period, and the range period.
前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を、ドップラ期間のFFT結果のうち、SN比の高い反射点のドップラを用いて前記レンジ期間の参照信号を補正し、補正した参照信号により前記レンジ期間を相関処理してレンジを抽出し、前記通信期間の受信信号を抽出して前記ドップラで補正した参照信号により相関処理することによって前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記レンジ期間は前記ドップラを用いて参照信号を補正して相関処理することで目標の距離を出力する受信装置と
を具備するレーダシステム。 The pulse train of the radar that repeats the pulse is a pulse train of three pulse repetition frequencies of communication period, Doppler period and range period, or two pulse repetition frequencies of communication period, Doppler period and range period, and the communication information related to transmission is superimposed on the pulse of the communication period. Then, the transmission device that mixes and transmits the pulse trains of the communication period, the Doppler period, and the range period, and
The direct wave transmitted from the transmitter or the reflected wave from the target is received, and the received signal is used as the reference signal of the range period using the Doppler of the reflection point having a high SN ratio among the FFT results of the Doppler period. The communication information is extracted by correlating the range period with the corrected reference signal and extracting the range, extracting the received signal of the communication period and correlating with the reference signal corrected by the Doppler. A radar system including a receiving device that outputs a target distance by correcting a reference signal using the Doppler and performing correlation processing for other reflection points having a low signal-to-noise power ratio during the range period.
前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を、ドップラ期間のFFT結果のうち、信号対雑音電力比(SN)の高い反射点のドップラを用いて前記レンジ期間の参照信号を補正し、補正した参照信号により前記レンジ期間を相関処理してレンジを抽出し、前記通信期間の受信信号を抽出して前記ドップラで補正した参照信号により相関処理することによって前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記通信期間は前記通信情報と前記ドップラを用いて第1の参照信号を補正し、前記レンジ期間は前記ドップラを用いて第2の参照信号を補正して、第1の参照信号と第2の参照信号を合わせた参照信号を用いて相関処理することで目標の距離を出力する受信装置と
を具備するレーダシステム。 The pulse train of the radar that repeats the pulse is made into a pulse train having two pulse repetition frequencies, that is, the Doppler period, the communication period, and the range period, and the communication information regarding transmission is superimposed on the pulse of the communication period, so that the communication period, the Doppler period, and the range are used. A transmitter that mixes and transmits pulse trains for a period, and
The direct wave transmitted from the transmitter or the reflected wave from the target is received, and the received signal is used as the Doppler at the reflection point having a high signal-to-noise power ratio (SN) in the FFT result of the Doppler period. By correcting the reference signal of the range period, correlating the range period with the corrected reference signal to extract the range, extracting the received signal of the communication period, and correlating with the reference signal corrected by the Doppler. The communication information is extracted, and for other reflection points having a low signal-to-noise power ratio, the first reference signal is corrected by using the communication information and the Doppler during the communication period, and the Doppler is used during the range period. A radar system including a receiving device that outputs a target distance by correcting a second reference signal using the reference signal and performing correlation processing using a reference signal obtained by combining the first reference signal and the second reference signal. ..
受信装置が、前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を前記レンジ期間の参照信号で圧縮し、信号対雑音電力比(SN)の高い反射点を用いて前記通信期間を抽出して相関処理することにより前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記レンジ期間のみまたは前記通信情報を用いて、前記通信期間及び前記レンジ期間のパルス全体で相関処理することによって目標の距離を出力する
レーダシステムのレーダ信号処理方法。 The transmission device divides the transmission pulse for pulse compression into a communication period and a range period, superimposes communication information on transmission on the pulse of the communication period, and transmits the pulse.
The receiving device receives the direct wave transmitted from the transmitting device or the reflected wave from the target, compresses the received signal with the reference signal during the range period, and obtains a reflection point having a high signal-to-noise ratio (SN). The communication period is extracted by extracting the communication period and performing correlation processing, and the communication period is also obtained for other reflection points having a low signal-to-noise power ratio using only the range period or using the communication information. And a radar signal processing method of a radar system that outputs a target distance by correlating the entire pulse of the range period.
受信装置が、前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を前記ドップラ期間のFFT結果のうち、信号対雑音電力比(SN)の高い反射点のドップラを用いて前記レンジ期間の参照信号を補正し、補正した参照信号により前記レンジ期間を相関処理してレンジを抽出し、通信期間の受信期間を抽出して前記ドップラで補正した参照信号により相関処理することによって前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記通信期間は前記通信情報と前記ドップラを用いて参照信号を補正し、前記レンジ期間は前記ドップラを用いて参照信号を補正し、前記通信期間、前記ドップラ期間、前記レンジ期間のうち、少なくとも前記レンジ期間を含むパルス列で用いて相関処理して目標の距離を出力する
レーダシステムのレーダ信号処理方法。 The transmitter divides the pulse train of the radar that repeats the pulse into a communication period, a Doppler period, and a range period, superimposes the communication information on the transmission on the pulse of the communication period, and transmits the pulse.
The receiving device receives the direct wave transmitted from the transmitting device or the reflected wave from the target, and the received signal is the Doppler of the reflection point having a high signal-to-noise power ratio (SN) in the FFT result of the Doppler period. Is used to correct the reference signal of the range period, the range period is correlated with the corrected reference signal to extract the range, the reception period of the communication period is extracted, and the reference signal corrected by the Doppler is used for correlation processing. By doing so, the communication information is extracted, and for other reflection points having a low signal-to-noise power ratio, the reference signal is corrected by using the communication information and the Doppler during the communication period, and the Doppler is used during the range period. A radar signal processing method of a radar system that corrects a reference signal by using it, performs correlation processing by using it in a pulse train including at least the range period among the communication period, the Doppler period, and the range period, and outputs a target distance.
受信装置が、前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を、ドップラ期間のFFT結果のうち、信号対雑音電力比(SN)の高い反射点のドップラを用いて前記レンジ期間の参照信号を補正し、補正した参照信号により前記レンジ期間を相関処理してレンジを抽出し、前記通信期間の受信信号を抽出して前記ドップラで補正した参照信号により相関処理することによって前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記レンジ期間は前記ドップラを用いて参照信号を補正して相関処理することで目標の距離を出力する
レーダシステムのレーダ信号処理方法。 The transmission device sets the pulse train of the radar that repeats the pulse as a pulse train of three pulse repetition frequencies of communication period, Doppler period and range period, or two pulse repetition frequencies of communication period, Doppler period and range period, and transmits to the pulse of the communication period. By superimposing the communication information, the pulse trains of the communication period, the Doppler period, and the range period are mixed and transmitted.
The receiving device receives the direct wave transmitted from the transmitting device or the reflected wave from the target, and the received signal is used as the Doppler at the reflection point having a high signal-to-noise power ratio (SN) in the FFT result during the Doppler period. Is used to correct the reference signal of the range period, the range period is correlated with the corrected reference signal to extract the range, the received signal of the communication period is extracted, and the reference signal corrected by the Doppler is correlated. The communication information is extracted by processing, and even for other reflection points with a low signal-to-noise power ratio, the target distance is output by correcting the reference signal using the Doppler and performing correlation processing during the range period. Radar signal processing method of the radar system.
受信装置が、前記送信装置から送信される直接波または目標からの反射波を受信し、その受信信号を、ドップラ期間のFFT結果のうち、信号対雑音電力比(SN)の高い反射点のドップラを用いて前記レンジ期間の参照信号を補正し、補正した参照信号により前記レンジ期間を相関処理してレンジを抽出し、前記通信期間の受信信号を抽出して前記ドップラで補正した参照信号により相関処理することによって前記通信情報を抽出し、信号対雑音電力比の低い他の反射点についても、前記通信期間は前記通信情報と前記ドップラを用いて第1の参照信号を補正し、前記レンジ期間は前記ドップラを用いて第2の参照信号を補正して、第1の参照信号と第2の参照信号を合わせた参照信号を用いて相関処理することで目標の距離を出力する
レーダシステムの信号処理方法。 The transmission device sets the pulse train of the radar that repeats the pulse as a pulse train of two pulse repetition frequencies, the Doppler period, the communication period, and the range period, and superimposes the communication information on transmission on the pulse of the communication period, and the Doppler during the communication period. The pulse trains of the period and the range period are mixed and transmitted.
The receiving device receives the direct wave transmitted from the transmitting device or the reflected wave from the target, and the received signal is used as the Doppler at the reflection point having a high signal-to-noise power ratio (SN) in the FFT result during the Doppler period. Is used to correct the reference signal of the range period, the range period is correlated with the corrected reference signal to extract the range, the received signal of the communication period is extracted, and the reference signal corrected by the Doppler is correlated. The communication information is extracted by processing, and for other reflection points having a low signal-to-noise power ratio, the communication period is corrected by using the communication information and the Doppler to correct the first reference signal, and the range period. Is a radar system signal that outputs a target distance by correcting the second reference signal using the Doppler and performing correlation processing using a reference signal that is a combination of the first reference signal and the second reference signal. Processing method.
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