Target echo relay method and apparatus

Abstract

The application discloses a target echo relay method and device, the method comprises the following steps: performing cross-range unit walking correction on an initial segmentation signal to obtain a corrected initial segmentation signal, wherein the initial segmentation signal is determined according to two relay receiving signals which do not require orthogonality; determining a predicted segmentation point according to the corrected initial segmentation signal, and segmenting the two relay receiving signals according to the predicted segmentation point to obtain two corrected receiving signals; estimating motion parameters of the corrected receiving signals, and compensating a first corrected receiving signal according to the motion parameters to obtain a compensated first corrected receiving signal; splicing the second corrected receiving signal and the compensated first corrected receiving signal to obtain a fusion receiving signal, so as to detect a target according to the fusion receiving signal. Since the application does not require the orthogonality of the relay receiving signals when determining the initial segmentation signal, the application range of the application can be expanded, and the signal processing effect can be enhanced.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of radar signals, and particularly relates to a target echo relay method and device. BACKGROUND

[0002] A low-orbit satellite is used as a radiation source, and a ground receiving end is used to form an external radiation source radar detection system, which has the advantages of wide coverage and strong anti-stealth capability, and is one of the development trends of future radars. When a low-orbit satellite irradiating a target is switched due to its high-speed movement relative to the ground, the target echo parameters will change suddenly, which is not conducive to coherent accumulation and reduces the target detection probability during satellite switching. At present, there are few studies on low-orbit satellite external radiation source radar detection systems, and no technical scheme for low-orbit satellite echo signal relay is given in the literature, but the existing multi-radiation source fusion or multi-motion stage fusion technology can achieve similar functions.

[0003] Chen Weijia gives a multi-radiation source fusion method in the literature "Air Weak Target Enhancement Algorithm Based on GPS External Radiation Source". Specifically, the orthogonality of the communication signal is used to separate the signal, and then the GSKT-MFP correction algorithm is used to realize the coherent accumulation of the separated signal, and then the motion parameter difference of each signal history is estimated and compensated for alignment, and finally each signal is added to realize the coherent accumulation of the multi-radiation source signal.

[0004] However, this method requires the orthogonality of the signal, and accumulates the part without signal, which introduces more noise and interference. This leads to a narrow application range and poor signal processing effect of this method. SUMMARY

[0005] The embodiments of the application provide a target echo relay method and device, which can solve the problem of narrow application range and poor signal processing effect of the current method.

[0006] In a first aspect, the embodiments of the application provide a target echo relay method, which comprises the following steps:

[0007] The initial segmented signal is corrected by moving across the distance unit to obtain a corrected initial segmented signal, wherein the initial segmented signal is determined according to two relay receiving signals which do not require orthogonality;

[0008] The prediction segmentation point is determined according to the corrected initial segmented signal, and the two relay receiving signals are segmented according to the prediction segmentation point to obtain two corrected receiving signals;

[0009] The motion parameters of the corrected receiving signals are estimated, and the first corrected receiving signal is compensated according to the motion parameters to obtain a compensated first corrected receiving signal, wherein the first corrected receiving signal is obtained according to the first relay receiving signal received first;

[0010] The second corrected reception signal is obtained according to the second relay reception signal received later.

[0011] In a possible implementation manner of the first aspect, before the initial segmented signal is corrected according to the cross-range cell migration to obtain a corrected initial segmented signal; the two relay reception signals are respectively column segmented from the initial segmentation point to obtain a first initial segmented signal and a second initial segmented signal; the first initial segmented signal and the second initial segmented signal are respectively sequentially subjected to a generalized second-order keystone transform (GSKT) and a matched filtering process to correct the cross-range cell migration and the cross-Doppler cell migration of the first initial segmented signal and the second initial segmented signal, and to obtain a corrected first initial segmented signal and a corrected second initial segmented signal; and the initial segmented signal is determined according to the corrected first initial segmented signal and the corrected second initial segmented signal.

[0012] For example, the first initial segmented signal includes C1 column data of the first relay reception signal, and the C1 is the initial segmentation point; and the second initial segmented signal includes N-C1 column data of the second relay reception signal, and the N is the dimension of the relay reception signal.

[0013] In a possible implementation manner of the first aspect, the initial segmentation point can be obtained by rounding the midpoint of the column of the relay reception signal.

[0014] In a possible implementation manner of the first aspect, the peak value of the corrected first initial segmented signal and the corrected second initial segmented signal after coherent accumulation can be compared; if the peak value of the corrected first initial segmented signal is greater than or equal to the peak value of the corrected second initial segmented signal, the GSKT is performed on the first relay reception signal, and the initial segmented signal is generated according to the C1 column data of the transformed first relay reception signal, wherein the C1 t1 ∈[1,C t1 ] and the C1 s ∈[C t2 ] and the C1 t2 ∈[1,C s ].

[0015] In a possible implementation manner of the first aspect, the predicted segmentation point can satisfy the following formula:

[0016]

[0017] wherein C s is the predicted segment point, represents taking the C t value that maximizes the function, C t =C t1 or C t2 , sum represents a summation operation, abs represents an absolute value operation, d″ t (t, t a , C t ) is the corrected initial segmentation signal, t a is the value of the slow time after the GSKT, and t is the fast time.

[0018] In a possible implementation manner of the first aspect, the initial segmentation signal can be corrected by a time axis reversal transformation algorithm to obtain the corrected initial segmentation signal.

[0019] In a possible implementation manner of the first aspect, the first corrected received signal can be coarsely compensated by a coarse compensation function determined by the motion parameter to obtain a coarsely compensated first corrected received signal; and the coarsely compensated first corrected received signal can be finely compensated by a fine compensation function to obtain the compensated first corrected received signal.

[0020] For example, the fine compensation function is determined according to compensation errors in the coarse compensation process, and the compensation errors are caused by compensation accuracy of the initial distance, compensation accuracy of the Doppler and search step length of the acceleration in the coarse compensation process; the compensation error caused by the compensation accuracy of the initial distance belongs to the set [0, 1], the compensation error caused by the compensation accuracy of the Doppler belongs to the set [-doppler_bin, doppler_bin], and doppler_bin is the average value of Doppler bin sizes of the first corrected received signal and the second corrected received signal after the moving target detection.

[0021] In a possible implementation manner of the first aspect, the compensation errors caused by the compensation accuracy of the initial distance, the compensation accuracy of the Doppler and the search step length of the acceleration can be searched by an alternating projection method; the fine compensation function is determined according to the compensation errors caused by the compensation accuracy of the initial distance, the compensation accuracy of the Doppler and the search step length of the acceleration, and the coarsely compensated first corrected received signal is finely compensated according to the fine compensation function to obtain the compensated first corrected received signal.

[0022] In a possible implementation manner of the first aspect, the compensated first corrected received signal can satisfy the following formula:

[0023]

[0024] wherein s″ MFP1 (t, t aIFFT, FFT respectively represent inverse Fourier transform and Fourier transform, s' (t, t) is the first corrected receiving signal after the compensation, H MFP1 (t, t a ) is the first corrected receiving signal after the rough compensation, H R (ΔR) is a distance fine compensation function, ΔR is a compensation error caused by the compensation precision of the initial distance, is a Doppler fine compensation function, Δf d is a compensation error caused by the compensation precision of the Doppler, a (Δa) is an acceleration fine compensation function, Δa is a compensation error caused by the search step of the acceleration.

[0025] In a second aspect, an embodiment of the present application provides a target echo relay device, the device comprising a processing unit; the processing unit is configured to:

[0026] perform a cross-range cell migration correction on an initial segmented signal to obtain a corrected initial segmented signal, wherein the initial segmented signal is determined according to two relay receiving signals which do not require orthogonality;

[0027] determine a predicted segmentation point according to the corrected initial segmented signal, and segment two relay receiving signals according to the predicted segmentation point to obtain two corrected receiving signals, wherein the two relay receiving signals are obtained by a target reflecting emission signals of two relay sending ends in turn;

[0028] estimate a motion parameter of the corrected receiving signal, and compensate a first corrected receiving signal according to the motion parameter to obtain a compensated first corrected receiving signal, wherein the first corrected receiving signal is obtained according to a first relay receiving signal received first;

[0029] splice the second corrected receiving signal and the compensated first corrected receiving signal to obtain a fused receiving signal, so as to detect the target according to the fused receiving signal, wherein the second corrected receiving signal is obtained according to a second relay receiving signal received later.

[0030] Compared with the prior art, the embodiment of the present application has the beneficial effects that: since the present application does not require the orthogonality of the relay receiving signal when determining the initial segmented signal, the application range of the method provided by the present application can be expanded; at the same time, the noise and interference introduced by the accumulation of the signal-free part when the signal is segmented by using the orthogonality of the signal can be avoided, so that the signal processing effect can be enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a working scene schematic diagram of a passive radar detection system provided by the embodiment of the present application;

[0032] Figure 2A scene schematic diagram for determining an initial segmentation signal by a receiving end provided by an embodiment of the present application;

[0033] Figure 3 A scene schematic diagram for determining a corrected receiving signal by a receiving end provided by an embodiment of the present application;

[0034] Figure 4 A flow schematic diagram of a target echo relay method provided by an embodiment of the present application;

[0035] Figure 5 A schematic diagram of peak value change with a predicted segmentation point for non-coherent accumulation provided by an embodiment of the present application;

[0036] Figure 6a 、 Figure 6b A result schematic diagram of coherent accumulation of a detected first corrected receiving signal and a detected second corrected receiving signal provided by an embodiment of the present application, respectively;

[0037] Figure 7 A result schematic diagram of coherent accumulation of a fused receiving signal provided by an embodiment of the present application;

[0038] Figure 8 A structure schematic diagram of a target echo relay device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0039] The present application will be further described in detail below with specific embodiments, but the embodiments of the present application are not limited thereto.

[0040] Figure 1 A working scene schematic diagram of an external radiation source radar detection system provided by an embodiment of the present application is shown.

[0041] Referring to Figure 1 , relay transmitting end satellites 1 and 2 pass through the area where the target and the receiving end are located in succession, and transmit transmitting signals to the target on the ground; the target reflects the two transmitting signals in turn according to the time of signal arrival; the receiving end can thus receive the relay signals reflected by the target, and obtain relay receiving signals by preliminarily processing the receiving signals, and the subsequent receiving end can detect the target according to the relay receiving signals.

[0042] In one example, the transmitting signal of the satellite n (n = 1 or 2) can satisfy the following formula:

[0043]

[0044] Where s tn (t) is the transmitting signal of the satellite n, t is the fast time, T p is the pulse width of the transmitting signal, μ is the frequency modulation slope, fc Let Δf be the carrier frequency. n For difference frequency,

[0045] For example, the transmitted signals from two satellites can be non-orthogonal signals.

[0046] In one example, the receiver can use the direct wave signals from satellite 1 and satellite 2 as reference signals to perform pulse compression processing on the two received signals to obtain a relay received signal.

[0047] For example, the received signal can satisfy the following formula:

[0048]

[0049] Among them, s r (t,t m ) represents the received signal, s tn For the transmitted signal of satellite n, A n R is the echo amplitude of satellite n. n (t m Let t be the echo distance of satellite n, c be the speed of light, and t be the echo distance of satellite n. m This is a slow time.

[0050] in:

[0051]

[0052]

[0053] Among them, t s For satellite switching time, t c The total time for one coherent accumulation.

[0054] For example, the distance between the satellite's direct wave and echo can be calculated based on the "stop-go" approximation theory, and the relay reception signal can be determined using the direct wave as a reference signal. The relay reception signal can satisfy the following formula:

[0055] s pn (t,t m )=σ n g n (t m )sinc[B(tR′ n (t m ) / c)]exp[-j2πR′ n (t m ) / λ]+s′ pn (t,t m (n=1,2)

[0056] Among them, s pn (t,tm ) represents the nth relay received signal. The first relay received signal is obtained from the signal reflected by satellite 1, which is ahead of the target, and the second relay received signal is obtained from the signal reflected by satellite 2, which is behind the target. σ n Let R' be the signal amplitude of satellite n, B be the bandwidth of the signals transmitted by the two satellites, and R' be the signal amplitude of satellite n. n (t m ) represents the equivalent distance between satellite n after echo pulse compression, λ represents the wavelength of the signals transmitted by the two satellites, and s′ represents the distance between them. pn (t,t m ) represents the residual term generated during pulse compression due to signal non-orthogonality.

[0057] For example, the equivalent distance of satellite n after echo pulse compression can satisfy the following formula:

[0058]

[0059] Among them, R dn (t m R is the direct wave distance of satellite n. 0,n v n a n These represent the equivalent initial distance, radial velocity, and radial acceleration after satellite n-echo pulse compression, respectively.

[0060] Figure 2 The diagram shown illustrates a scenario where a receiver determines an initial segmentation signal according to an embodiment of the present invention.

[0061] As an example, the receiving end can determine the initial segmentation signal through steps S2021-S2025.

[0062] S2011, the two relay received signals are column-segmented from the initial segmentation point to obtain the first initial segmentation signal and the second initial segmentation signal.

[0063] For example, the first initial segmentation signal d1(t,t) m This may include the first relay receiving signal s p1 (t,t m The first C1 columns of data, where C1 is the initial segmentation point, and the second initial segmentation signal d2(t,t) is used. m This includes the second relay receiving signal s p2 (t,t m The data in the last N-C1 columns of the table.

[0064] For example, see Figure 2 The first initial segmentation signal can be obtained by extracting the first C1=2 columns of data from the first relay received signal; the second initial segmentation signal can be obtained by extracting the data after the second relay received signal starting from the second column.

[0065] It should be understood that, for ease of explanation, the relay receiving signal is set as a 5×8 matrix with an initial segmentation point of 2. In reality, the scale of the relay receiving signal and the value of the initial segmentation point are much larger.

[0066] S2012, GSKT and matched filtering are performed on the first initial segmentation signal and the second initial segmentation signal respectively to correct the cross-distance cell movement and cross-Doppler cell movement of the first initial segmentation signal and the second initial segmentation signal, respectively, to obtain the corrected first initial segmentation signal and the corrected second initial segmentation signal.

[0067] For example, the first initial segmentation signal and the second initial segmentation signal can be corrected by sequentially using the General Second-order Keystone Transform (GSKT) and the Matched Filtering Process (MFP) to obtain the corrected first initial segmentation signal and the corrected second initial segmentation signal.

[0068] Optionally, when performing GSKT, the velocity ambiguity factor can be searched and compensated, and the search range can be determined according to the velocity ambiguity factor of the corresponding satellite direct wave.

[0069] S2013, compare the peak values ​​of the corrected first initial segmentation signal and the corrected second initial segmentation signal.

[0070] For example, moving target detection (MTD) can be performed on the corrected first initial segmentation signal and the corrected second initial segmentation signal. Then, the peak values ​​of the detected first initial segmentation signal and the second initial segmentation signal are compared.

[0071] In one example, if the peak value TOP1 of the detected first initial segmentation signal is greater than or equal to the peak value TOP2 of the detected second initial segmentation signal, then step S2014 can be performed.

[0072] In another example, if the peak value TOP1 of the first initial segmentation signal after detection is less than the peak value TOP2 of the second initial segmentation signal after detection, then step S2015 can be performed.

[0073] S2014, perform GSKT on the first relay received signal, and based on the transformed first relay received signal, perform C... t1 The column data generates the initial segmentation signal.

[0074] For example, the first relay receiving signal s can be... p1 (t,t mPerform GSKT to obtain the transformed first relay received signal d. t (t,t a C t After GSKT, the time scale also changes, with the slower time scale changing from t... m Change to t a .

[0075] Optionally, when performing GSKT, it is not necessary to search for and compensate for the velocity ambiguity factor.

[0076] For example, C t1 ∈[C s ,N]. For example Figure 2 It can extract the first C of the transformed first relay received signal. t1 =3 columns of data to obtain the initial segmentation signal D1.

[0077] S2015, perform GSKT on the second relay received signal, and based on the transformed second relay received signal, perform NC... t2 The column data generates the initial segmentation signal.

[0078] Similarly, the second relay receiving signal s can be... p2 (t,t m Perform GSKT to obtain the transformed second relay received signal d. t (t,t a C t ).

[0079] Optionally, when performing GSKT, it is not necessary to search for and compensate for the velocity ambiguity factor.

[0080] For example, C t2 ∈[1,C s ].For example Figure 2 It can be seen from the Cth t2 =Starting from column 1, extract the NC signal after transformation of the second relay received signal. t2 The column data generates the initial segmentation signal D2.

[0081] Figure 3 The diagram shown is a scenario where a receiver determines and corrects a received signal according to an embodiment of the present invention.

[0082] As an example, see Figure 3 The receiving end can receive the signal s from the first relay. p1 (t,t m The first column to the Cth column s Column data, such as columns 1 to 3, are used to generate the first predicted segmentation signal d. s1 (t,t m); where C s To predict the segmentation point. Based on the second relay received signal s p2 (t,t m The Cth s Data from column +1 to column N, for example, columns 4 to 5, are used to generate the second predictive segmentation signal d. s2 (t,t m Then, the first predicted segmentation signal is arranged in reverse column order to obtain the reversed first predicted segmentation signal. Finally, the reverse-ordered first prediction segmentation signal is corrected sequentially using GSKT and MFP. Second predicted segmentation signal d s2 (t,t m The first corrected received signal is obtained by measuring the distance and Doppler movement of the signal. Second correction received signal s MFP2s (t,t a ).

[0083] The target echo relay method provided in this embodiment of the invention can be applied to signal receiving terminals such as radar. This embodiment of the invention does not impose any restrictions on the specific type of signal receiving terminal.

[0084] Figure 4 The diagram shown illustrates a target echo relay method according to an embodiment of the present invention. As a compromise and not a limitation, method 400 can be applied to the aforementioned signal receiver. Method 400 may include steps S401-S407, which are described below.

[0085] S401, based on the initial segmentation point, the receiving force signal is segmented to obtain the initial segmentation signal.

[0086] In one example, the receiving end can obtain the initial segmented signal using the methods described in steps S2011-S2015 above. Please refer to the description of steps S2011-S2015 in the above embodiments for details, which will not be repeated here.

[0087] For example, see Figure 2 Relay receiving signal s pn (t,t m ) can be an M×N matrix.

[0088] For example, the initial segment point is obtained by rounding down the midpoint of the received force signal. It can satisfy the following formula:

[0089] C1 = ceil(N / 2)

[0090] Where C1 is the initial segmentation point, and ceil(·) represents rounding up.

[0091] Since the initial segmentation point is obtained by rounding down the midpoint of the column, it is independent of the orthogonality of the relay received signals. Therefore, it is not required that the relay received signals be orthogonal.

[0092] S402, perform cross-distance cell movement correction on the initial segmentation signal to obtain the corrected initial segmentation signal.

[0093] For example, the initial segmented signal d′ can be processed using the Time Reversing Transform (TRT) algorithm. t (t,t m C t Linear span cell movement correction is performed to obtain the corrected initial segmentation signal d″. t (t,t a C t Compared to the multi-motion-stage fusion method proposed by Li XL et al. in the paper "STGRFT for Detection of Maneuvering Weak TargetWi", which searches for the start and end times of each motion stage by applying a window, performs generalized Radon transform within each motion stage to achieve coherent accumulation, and finally directly adds the coherent accumulation results of each stage, the TRT algorithm does not require searching within a time window, which can greatly reduce the amount of computation.

[0094] S403 determines the predicted segmentation point based on the corrected initial segmentation signal.

[0095] For example, the predicted segmentation points can satisfy the following formula:

[0096]

[0097] Among them, C s To predict the segmentation points, Represents taking C that maximizes the function. t The value of C t =C t1 Or C t2 `sum` represents the summation operation, `abs` represents the absolute value operation, and `d″` represents the absolute value operation. t (t,t a C t ) represents the corrected initial segmentation signal, t a t represents the value after the slow time passes through GSTK, and t represents the fast time.

[0098] Optionally, when the initial segmentation signal is generated from the first relay received signal, C t =C t1 When the initial segmentation signal is generated by the second relay receiving signal, C t =C t2.

[0099] Similarly, the orthogonality of the signals is not involved in determining the predicted segmentation points, and the non-orthogonality of the signals has already been taken into account when the relay receiving signals were previously determined; therefore, the present invention can segment signals without relying on the orthogonality of the signals.

[0100] S404, based on the predicted segmentation point, divides the two relay received signals to obtain two corrected received signals.

[0101] For example, the above embodiments and Figure 3 The relevant methods determine the corrected received signal.

[0102] S405, Estimate and correct motion parameters of the received signal.

[0103] In one example, moving target detection can be performed on two corrected received signals to obtain the first corrected received signal after detection. and the second corrected received signal s after detection mtd2 (t,f d Then, the motion parameters of the corrected received signal are estimated based on the peak value of the coherent accumulation of the two detected corrected received signals.

[0104] For example, the motion parameters may include: the initial distance and initial velocity estimates of the first corrected received signal, and the initial distance and initial velocity estimates of the second corrected received signal.

[0105] For example, the estimated motion parameters can satisfy the following formula:

[0106]

[0107] in, The initial range estimate for the first corrected received signal is given by range_bin, where range_bin is the size of a range cell, and l1 and l2 represent the range cells where the peak value of the two signal segments is located after coherent accumulation; R 0,2 This is the initial distance estimate for the second corrected received signal; v1 represents the initial velocity estimate of the first corrected received signal, m1 and m2 represent the Doppler cells where the peak value of the two signals is located after coherent accumulation, doppler_bin1 is the size of the Doppler cell of the first corrected received signal after detection; v2 represents the initial velocity estimate of the second corrected received signal, doppler_bin2 is the size of the Doppler cell of the second corrected received signal after detection.

[0108] S406, the first corrected received signal is obtained by compensating the first corrected received signal according to the motion parameters.

[0109] In some embodiments, a coarse compensation function can be determined based on motion parameters, and then the first corrected received signal can be coarsely compensated according to the coarse compensation function to obtain the coarsely compensated first corrected received signal; then the coarsely compensated first corrected received signal can be finely compensated using a fine compensation function to obtain the compensated first corrected received signal.

[0110] In one possible implementation, the coarse compensation function can satisfy the following formula:

[0111]

[0112] Where H1 is the coarse compensation function.

[0113] The first corrected received signal after coarse compensation can satisfy the following formula:

[0114]

[0115] Among them, s′ MFP1 (t,t a The signal is the first corrected received signal after coarse compensation. IFFT and FFT represent the inverse Fourier transform and Fourier transform, respectively. This is the first corrected received signal.

[0116] In one possible implementation, the compensation error caused by the initial distance compensation accuracy, Doppler compensation accuracy, and acceleration search step size during the coarse compensation process can be searched using the alternating projection method. The fine compensation function is determined based on the compensation error caused by the initial distance compensation accuracy, Doppler compensation accuracy, and acceleration search step size. The first corrected received signal after coarse compensation is then finely compensated based on the fine compensation function to obtain the first corrected received signal after compensation.

[0117] For example, the fine compensation function may include a range fine compensation function, a Doppler fine compensation function, and an acceleration fine compensation function. These can be determined based on the compensation accuracy of the initial range, the compensation accuracy of the Doppler, and the compensation error caused by the search step size of the acceleration, respectively.

[0118] In one example, the fine compensation function can satisfy the following formula:

[0119] H R (ΔR)=exp(j2πΔR)

[0120]

[0121]

[0122] Among them, H R (ΔR) is the distance fine compensation function, where ΔR is the compensation error caused by the initial distance compensation accuracy. Let Δf be the Doppler fine compensation function. d The compensation error caused by the Doppler compensation accuracy, H a (Δa) is the acceleration fine compensation function, where Δa is the compensation error caused by the search step size of the acceleration.

[0123] in:

[0124]

[0125] in, accu_bin is the step size for acceleration search in MFP.

[0126] The compensated first corrected received signal can satisfy the following formula:

[0127]

[0128] Among them, s″ MFP1 (t,t a ) represents the first corrected received signal after compensation, where IFFT and FFT represent the inverse Fourier transform and Fourier transform, respectively, and s′ MFP1 (t,t a () represents the first corrected received signal after coarse compensation.

[0129] S407, the second corrected received signal and the compensated first corrected received signal are spliced ​​together to obtain a fused received signal, so as to detect the target based on the fused received signal.

[0130] In one example, the second corrected received signal and the compensated first corrected received signal can be spliced ​​together to obtain a fused received signal. Then, moving target detection is performed on the fused received signal to complete the signal relay and target detection and identification at the relay transmitter.

[0131] For example, the peak value of the fused received signal after moving target detection is maximized by using the compensation accuracy of the initial distance, the compensation accuracy of Doppler, and the compensation error caused by the search step size of acceleration.

[0132] Since this invention does not require the orthogonality of the relay received signals when determining the initial segmentation signal, it expands the application scope of the method provided by this invention. Simultaneously, it avoids the noise and interference introduced by the accumulation of non-signal portions when segmenting signals using signal orthogonality, thereby enhancing the signal processing effect. Furthermore, since this invention uses the TRT algorithm to correct the signal, it eliminates the need for multi-time-window searches, reducing computational load and improving processing efficiency. By searching for the compensation accuracy of the initial distance, the compensation accuracy of Doppler, and the possible compensation errors caused by the search step size of acceleration using the alternating projection method, and determining the fine compensation function to compensate the first corrected received signal using these search values, the signal quality of the compensated first corrected received signal can be improved. Compensating the first corrected received signal using coarse and fine compensation functions can increase the target detection probability during signal switching.

[0133] To better illustrate the beneficial effects of the method provided by this invention, the following simulation experiments were conducted:

[0134] For example, see Figure 1 In the simulation experiment, the satellite, target, and receiver are located in the same two-dimensional command and control coordinate system, with the ground receiver as the origin. The initial coordinates of satellite 1 are [400 1000] km, and its velocity is [8000 0] m / s; the initial coordinates of satellite 2 are [-400 1000] km, and its velocity is [8000 0] m / s; the initial coordinates of the target are [3 8] km, and its velocity is [100 300] m / s.

[0135] The radar system parameters at the ground receiver are shown in Table 1.

[0136] Table 1

[0137]

[0138] For example, in the simulation experiment, both relay received signals are 1000×2000 order matrices, with an initial segmentation point C1 = 1000. Based on the first relay received signal s... p1 (t,t m The first initial segmentation signal d1(t,t) is generated from columns 1 to 1000. m The second relay receives the signal s. p2 (t,t m The second initial segmentation signal d2(t,t) is generated from columns 1001 to 2000. m ).

[0139] Then, based on the first initial segmentation signal d1(t,t)... m ) and the second initial segmented signal d2(t,t m Generate the initial segmentation signal, see [link / reference] Figure 5It can be seen that the C used when generating the initial segmentation signal t1 Or C t2 The closer the value is to the true split point, the higher the peak value of the non-coherent accumulation.

[0140] After determining the initial segmentation signal using the first and second initial segmentation signals, the predicted segmentation point can be determined based on the initial segmentation signal. In the simulation experiment, the value of the predicted segmentation point C... s =1198, the actual segmentation point is 1200. This error is caused by noise and energy fluctuations due to distance cell grid mismatch. Increasing the sampling frequency can reduce the range of errors.

[0141] Then the first relay receiving signal s can be obtained. p1 (t,t m Columns 1 to 1198 of the first prediction segmentation signal d s1 (t,t m ), take the second relay received signal s p2 (t,t m Columns 1199 to 2000 of the second predictive segmentation signal d s2 (t,t m The first corrected received signal after detection is determined based on these two signals. and the second corrected received signal s after detection mtd2 (t,f d Finally, according to and s mtd2 (t,f d Determine the fused received signal.

[0142] See Figure 6 and Figure 7 , Figure 6a , Figure 6b These are the results of coherently accumulating the first corrected received signal and the second corrected received signal after detection, respectively. Figure 7 This is the result of coherent accumulation of the fused received signal. It can be seen that the accumulated peak value of the fused received signal is approximately equal to the signal value. and s mtd2 (t,f d The superposition of peak values ​​after coherent accumulation.

[0143] Therefore, the method provided by the present invention can obtain more accurate predicted segmentation points, and determine the fused received signal based on the signal obtained by segmenting the predicted segmentation points, which enables the fused received signal to more closely approximate the performance of the real signal.

[0144] Figure 8A schematic diagram of a target echo relay device provided in an embodiment of the present invention is shown. Device 800 may be the receiving end in the above embodiment, and device 800 may include a processing unit 810.

[0145] Processing unit 810 can be used for:

[0146] The initial segmentation signal is corrected by cross-distance cell movement to obtain the corrected initial segmentation signal. The initial segmentation signal is determined based on two relay reception signals that do not require orthogonality.

[0147] The predicted segmentation point is determined based on the corrected initial segmentation signal, and the two relay received signals are divided according to the predicted segmentation point to obtain two corrected received signals.

[0148] The motion parameters of the corrected received signal are estimated, and the first corrected received signal is compensated based on the motion parameters to obtain the compensated first corrected received signal, wherein the first corrected received signal is obtained based on the first relay received signal received earlier.

[0149] The second corrected received signal and the compensated first corrected received signal are spliced ​​together to obtain a fused received signal, which is used to detect the target. The second corrected received signal is obtained based on the second relay received signal received later.

[0150] Since the present invention performs column segmentation of the signal starting from a preset initial segmentation point, rather than using the orthogonality of the signal to segment the signal, it can expand the application range of the device provided by the present invention; at the same time, it avoids the noise and interference introduced by the accumulation of non-signal parts when segmenting the signal using the orthogonality of the signal, thereby enhancing the signal processing effect.

[0151] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

Claims

1. A method for relaying target echoes, characterized in that, include: The initial segmentation signal is corrected by cross-distance cell movement to obtain the corrected initial segmentation signal, wherein the initial segmentation signal is determined based on two relay received signals that do not require orthogonality. The predicted segmentation point is determined based on the corrected initial segmentation signal, and the two relay received signals are segmented based on the predicted segmentation point to obtain two corrected received signals. The motion parameters of the corrected received signal are estimated, and the first corrected received signal is compensated according to the motion parameters to obtain the compensated first corrected received signal, wherein the first corrected received signal is obtained based on the first relay received signal received earlier. The second corrected received signal and the compensated first corrected received signal are spliced ​​together to obtain a fused received signal, which is used to detect the target based on the fused received signal, wherein the second corrected received signal is obtained based on the second relay received signal received later. The method further includes, before performing cross-range cell travel correction on the initial segmented signal to obtain the corrected initial segmented signal: The two relay received signals are respectively column-segmented from the initial segmentation point to obtain the first initial segmentation signal and the second initial segmentation signal; Wherein, the first initial segmentation signal includes the preceding signal of the first relay reception signal. Column data, As the initial segmentation point, the second initial segmentation signal includes the latter part of the second relay received signal. The data is in columns, where N is the dimension of the relay received signal; The first initial segmented signal and the second initial segmented signal are subjected to generalized second-order keystone transform (GSKT) and matched filtering respectively to correct the cross-range cell movement and cross-Doppler cell movement of the first initial segmented signal and the second initial segmented signal, respectively, to obtain the corrected first initial segmented signal and the corrected second initial segmented signal. The initial segmentation signal is determined based on the corrected first initial segmentation signal and the corrected second initial segmentation signal.

2. The method according to claim 1, characterized in that, The initial segmentation point is obtained by rounding down the midpoint of the relay received signal.

3. The method according to claim 1, characterized in that, Determining the initial segmentation signal based on the corrected first initial segmentation signal and the corrected second initial segmentation signal includes: Compare the peak values ​​of the corrected first initial segmented signal and the corrected second initial segmented signal after coherent accumulation; If the peak value of the corrected first initial segmentation signal is greater than or equal to the corrected second initial segmentation signal, then GSKT is performed on the first relay received signal, and the result is determined based on the transformed first relay received signal. The column data generates the initial segmentation signal, wherein, ; If the peak value of the corrected first initial segmentation signal is less than the corrected second initial segmentation signal, then GSKT is performed on the second relay received signal, and the result is determined based on the transformed second relay received signal. The column data generates the initial segmentation signal, wherein, .

4. The method according to claim 3, characterized in that, The predicted segmentation points satisfy the following formula: in, For the predicted segmentation point, This represents taking the option that maximizes the function. The value, or , This represents the summation operation. This indicates the absolute value operation. This refers to the corrected initial segmentation signal. This is the value after the slow time passes through GSKT. To save time.

5. The method according to claim 1, characterized in that, The step of performing cross-range cell movement correction on the initial segmented signal to obtain the corrected initial segmented signal includes: The initial segmented signal is corrected by performing cross-distance cell movement correction on the initial segmented signal using a time-axis reversal transformation algorithm, resulting in the corrected initial segmented signal.

6. The method according to claim 1, characterized in that, The step of obtaining the compensated first corrected received signal by compensating the first corrected received signal according to the motion parameters includes: The coarsely compensated first corrected received signal is obtained by performing coarse compensation on the first corrected received signal using a coarse compensation function determined by the motion parameters. The compensated first corrected received signal is obtained by performing fine compensation on the coarsely compensated first corrected received signal using a fine compensation function. The fine compensation function is determined based on the compensation error in the coarse compensation process. This compensation error is caused by the compensation accuracy of the initial distance, the compensation accuracy of Doppler, and the search step size of the acceleration in the coarse compensation process. The compensation error caused by the compensation accuracy of the initial distance belongs to the set... The compensation error caused by the Doppler compensation accuracy belongs to the set. , This is the average size of the Doppler cells of the first and second corrected received signals after moving target detection.

7. The method according to claim 6, characterized in that, The step of performing fine compensation on the coarsely compensated first corrected received signal using a fine compensation function to obtain the compensated first corrected received signal includes: The compensation accuracy of the initial distance, the compensation accuracy of the Doppler, and the compensation error caused by the search step size of the acceleration are searched using the alternating projection method. The fine compensation function is determined based on the compensation accuracy of the initial distance, the compensation accuracy of the Doppler, and the compensation error caused by the search step size of the acceleration. The fine compensation function is then used to perform fine compensation on the coarsely compensated first corrected received signal to obtain the compensated first corrected received signal.

8. The method according to claim 7, characterized in that, The compensated first corrected received signal satisfies the following formula: in, This refers to the first corrected received signal after compensation. , These represent the inverse Fourier transform and the Fourier transform, respectively. This is the first corrected received signal after coarse compensation. For distance fine compensation function, The compensation error is caused by the compensation accuracy of the initial distance. For the Doppler fine compensation function, The compensation error is caused by the compensation accuracy of the Doppler. For the acceleration fine compensation function, This is the compensation error caused by the search step size of the acceleration.

9. A target echo relay device, characterized in that, The device includes a processing unit, the processing unit being used for: The initial segmentation signal is corrected by cross-distance cell movement to obtain the corrected initial segmentation signal, wherein the initial segmentation signal is obtained by segmentation at preset initial segmentation points; The predicted segmentation point is determined based on the corrected initial segmentation signal, and the two relay receiving signals are divided according to the predicted segmentation point to obtain two corrected receiving signals. The two relay receiving signals are obtained by the target reflecting the transmitted signals of the two relay transmitters in sequence. The motion parameters of the corrected received signal are estimated, and the first corrected received signal is compensated according to the motion parameters to obtain the compensated first corrected received signal, wherein the first corrected received signal is obtained based on the first relay received signal received earlier. The second corrected received signal and the compensated first corrected received signal are spliced ​​together to obtain a fused received signal, which is used to detect the target based on the fused received signal, wherein the second corrected received signal is obtained based on the second relay received signal received later. Before the processing unit performs cross-distance unit movement correction on the initial segmented signal to obtain the corrected initial segmented signal, the processing unit is further configured to: The two relay received signals are respectively column-segmented from the initial segmentation point to obtain the first initial segmentation signal and the second initial segmentation signal; Wherein, the first initial segmentation signal includes the preceding signal of the first relay reception signal. Column data, As the initial segmentation point, the second initial segmentation signal includes the latter part of the second relay received signal. The data is in columns, where N is the dimension of the relay received signal; The first initial segmented signal and the second initial segmented signal are subjected to generalized second-order keystone transform (GSKT) and matched filtering respectively to correct the cross-range cell movement and cross-Doppler cell movement of the first initial segmented signal and the second initial segmented signal, respectively, to obtain the corrected first initial segmented signal and the corrected second initial segmented signal. The initial segmentation signal is determined based on the corrected first initial segmentation signal and the corrected second initial segmentation signal.

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