Time synchronization processing method and device for airborne double-station radar measurement system
Through GNSS second pulse correction and linear delay correction, the time delay problem caused by clock frequency differences in the airborne dual-station radar measurement system is solved, and the accuracy of the measurement data and the overall performance of the system are improved.
Patent Information
- Application Number
- CN202411369518.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-29
- Publication Date
- 2024-12-31
AI Technical Summary
In the airborne dual-station radar measurement system, due to the frequency difference between the clock source between the main station and the secondary station, the transmitting and receiving signals are delayed when there is a distance, which affects the accuracy of the measurement data.
Through GNSS second pulses, the local clock frequency of the main and auxiliary stations are corrected, frequency division signal processing and sampling synchronization processing are performed, and the echo signal is calculated and applied to correct the echo signal, so as to achieve consistency of the PRF sampling starting reference between the two stations. .
It improves the accuracy of airborne dual-station radar measurement data, reduces time delay, and enhances the application prospects and engineering value of the measurement system.
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Figure CN119224698A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of radar target measurement, and in particular to a time synchronization processing method and device for an airborne dual-station radar measurement system. Background Art
[0002] Airborne dual-station radar is a measurement system that can obtain electromagnetic scattering characteristic data of ground and sea targets under different dual-station angles. The extensive application of precision strike weapons against ground and sea has made airborne dual-station radar measurement play an increasingly prominent role in the study of ground and sea target characteristics. The system measures the electromagnetic scattering characteristics of the target by sending pulse signals at the main station and receiving echo signals reflected by the target at the secondary station.
[0003] In the related technology, since the main station and the secondary station are mounted on different aircraft platforms, there is a frequency difference in the clock sources between the two stations, which leads to a delay error in the distance direction of the transmitted and received signals, thereby affecting the accuracy of the airborne dual-station radar measurement data.
[0004] Based on this, there is an urgent need for a time synchronization processing method and device for an airborne dual-station radar measurement system to solve the above technical problems. Summary of the invention
[0005] The embodiment of the present invention provides a time synchronization processing method and device for an airborne bistatic radar measurement system, which can effectively improve the accuracy of airborne bistatic radar measurement data.
[0006] In a first aspect, an embodiment of the present invention provides a time synchronization processing method for an airborne dual-station radar measurement system, comprising:
[0007] The local clocks of the primary and secondary radar stations are frequency-divided to obtain the frequency-divided signals of the primary and secondary radar stations in turn, which satisfy the requirement that the GNSS pulse-per-second period is an integer multiple of the frequency-divided signal period.
[0008] According to the first rising edge time of the received GNSS second pulse, the frequency division signals of the primary and secondary radars are sampled and synchronously processed to obtain the primary and secondary radar synchronization signals whose rising edge time is the same as the error of the first rising edge time;
[0009] The linear time delay between the main station radar and the secondary station radar is calculated according to the first time series of the main station radar synchronization signal and the second time series of the secondary station radar synchronization signal;
[0010] The linear time delay is used to correct the initial echo sequence collected by the secondary station radar to obtain a final echo sequence that meets the synchronous sampling requirements.
[0011] In a second aspect, an embodiment of the present invention further provides a time synchronization processing device for an airborne dual-station radar measurement system, comprising:
[0012] The first processing module is used to perform frequency division processing on the local clocks of the primary and secondary radar stations, and obtain the frequency division signals of the primary and secondary radar stations in turn so that the GNSS pulse-period is an integer multiple of the frequency division signal period;
[0013] The second processing module is used to sample and synchronize the frequency division signals of the primary and secondary radar stations according to the first rising edge time of the received GNSS second pulse, so as to obtain the primary and secondary radar synchronization signals whose rising edge time has the same error as the first rising edge time;
[0014] A calculation module, used for calculating the linear time delay of the main station radar and the secondary station radar according to the first time series of the main station radar synchronization signal and the second time series of the secondary station radar synchronization signal;
[0015] The correction module is used to use the linear time delay to correct the initial echo sequence collected by the secondary station radar to obtain a final echo sequence that meets the synchronous sampling requirements.
[0016] In a third aspect, an embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method described in any embodiment of this specification is implemented.
[0017] In a fourth aspect, an embodiment of the present invention further provides a computer-readable storage medium having a computer program stored thereon, which, when executed in a computer, enables the computer to execute the method described in any embodiment of this specification.
[0018] The embodiment of the present invention provides a time synchronization processing method and device for an airborne dual-station radar measurement system. First, the local clock frequency PRF of the master and slave stations is corrected using the GNSS (Global Navigation Satellite System) second pulse, and then the time series of the corrected PRF is sampled to obtain the rising edge time series of the master and slave station signals, and the two time series are fitted and estimated to obtain the linear delay deviation of the master station system and the slave station, and finally the echo signal sequence of the slave station is corrected using the linear delay deviation. The method records the short-term frequency difference between the systems through the GNSS time tag, estimates the frequency difference of the dual-station system by a linear fitting, and uses the estimated value to correct the echo signal, thereby achieving the consistency of the PRF sampling starting reference between the dual stations, so that the delay of the transmitting and receiving signals in the distance direction meets the error requirements, and improves the accuracy of the airborne dual-station radar measurement data, which has a good application prospect and engineering value. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0020] Figure 1 It is a flow chart of a time synchronization processing method for an airborne dual-station radar measurement system provided by an embodiment of the present invention;
[0021] Figure 2 It is a schematic diagram of using GNSS second pulses to align and correct frequency-divided signals according to an embodiment of the present invention;
[0022] Figure 3 is a hardware architecture diagram of an electronic device provided by an embodiment of the present invention;
[0023] Figure 4 It is a structural diagram of a time synchronization processing device of an airborne dual-station radar measurement system provided by an embodiment of the present invention. DETAILED DESCRIPTION
[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.
[0025] As mentioned above, in the prior art, when measuring radar, the sampling starting reference of the frequency division signal between the primary and secondary stations is not synchronized, which leads to a delay error in the distance direction of the transmitted and received signals, thereby affecting the measurement data accuracy of the airborne dual-station radar.
[0026] Based on this, the concept of the present invention is to use GNSS second pulses to process the frequency-divided signals of the two stations, then perform linear fitting on the difference between the two station signals to obtain a time correction value, and use the correction value to correct the secondary station echo signal.
[0027] The specific implementation of the above concept is described below.
[0028] Please refer to Figure 1 The embodiment of the present invention provides a time synchronization processing method for an airborne dual-station radar measurement system, the method comprising:
[0029] Step 100, frequency division processing is performed on the local clocks of the primary and secondary radar stations, and the frequency division signals of the primary and secondary radar stations are obtained in sequence so that the GNSS pulse-period is an integer multiple of the frequency division signal period.
[0030] Step 102, sampling and synchronizing the frequency division signals of the primary and secondary radar stations according to the first rising edge time of the received GNSS second pulse, and obtaining the primary and secondary radar synchronization signals whose rising edge time has the same error as the first rising edge time;
[0031] Step 104, calculating the linear time delay of the primary station radar and the secondary station radar according to the first time series of the primary station radar synchronization signal and the second time series of the secondary station radar synchronization signal;
[0032] Step 106, using the linear time delay to correct the initial echo sequence acquired by the secondary station radar, to obtain a final echo sequence that meets the synchronous sampling requirements.
[0033] In the embodiment of the present invention, the local clock frequency PRF of the master and slave stations is corrected by using the GNSS second pulse, and then the time series of the corrected PRF is sampled to obtain the rising edge time series of the master and slave station signals, and the two time series are fitted and estimated to obtain the linear delay deviation of the master station system and the slave station, and finally the linear delay deviation is used to correct the echo signal sequence of the slave station. This method uses the GNSS time tag to record the short-term frequency difference between the systems, applies a linear fitting to estimate the frequency difference of the dual-station system, and uses the estimated value to correct the echo signal, thereby achieving the consistency of the PRF sampling starting reference between the dual stations, so that the delay of the transmitting and receiving signals in the distance direction meets the error requirements, and improves the accuracy of the airborne dual-station radar measurement data, which has a good application prospect and engineering value.
[0034] Described below Figure 1 How the various steps are performed.
[0035] First, for step 100, the local clocks of the primary and secondary radar stations are frequency-divided to obtain the frequency-divided signals of the primary and secondary radar stations in turn, satisfying that the GNSS second pulse period is an integer multiple of the frequency-divided signal period.
[0036] In an embodiment of the present invention, the master and slave station clocks are first divided by a local counter to obtain initial frequency-divided signals of the master and slave stations, and then the period of the initial frequency-divided signals is adjusted to satisfy the requirement that the period of the GNSS second pulse is an integer multiple of the period of the initial frequency-divided signal, thereby obtaining frequency-divided signals for subsequent steps.
[0037] Specifically, assuming that the local clock period of the master and slave stations is T clk Hz, the digital circuit divides the clock through the local counter to obtain the initial divided signal, whose period is T prf, the number of N in one cycle of the local clock prf , and then adjust it by the following formula:
[0038] F clk =F prf *N prf
[0039] The parameters in the above formula are all positive integers, thereby ensuring that the period of the GNSS second pulse is an integer multiple of the period of the initial frequency-divided signal, thereby ensuring the long-term stability of the two.
[0040] It is worth noting that the above process is the process of automatic frequency division of the system. If the frequency division signal period designed by the system cannot meet the above conditions, it is necessary to change T prf The frequency is reduced by a step of 1 until the above integer divisibility condition is met, so that a frequency-divided signal for subsequent processing steps can be obtained.
[0041] Then, for step 102, the divided frequency signals of the primary and secondary radars are sampled and synchronized according to the first rising edge time of the received GNSS second pulse to obtain primary and secondary radar synchronization signals whose rising edge time has the same error as the first rising edge time.
[0042] In an embodiment of the present invention, in order to ensure that the sampling windows of the master station and the slave station in the dual-station radar can be synchronized for a long time, the master station and the slave station reset the local counter each time they receive the rising edge of the GNSS second pulse. After the correction, the rising edge time of the frequency-divided signal of the master station and the slave station is consistent with the rising edge error of the GNSS second pulse, and the error will not accumulate over time.
[0043] For example, assuming that the frequency division signal period of the master and slave stations is 0.1 seconds, since the period of the GNSS second pulse is fixed at 1 second, after the master and slave stations simultaneously receive the GNSS second pulse at the 1st second, they simultaneously perform rising edge sampling. At this time, if sampling is performed without error, the master and slave station radars will simultaneously perform the tenth sampling at 1.9 seconds, and perform the eleventh sampling at the same time after receiving the GNSS second pulse again at the 2nd second.
[0044] However, in actual operation, due to the delay error between the master and slave stations, it is very likely that the master station samples the rising edge at 1.2 seconds, while the slave station starts sampling the rising edge at 1.25 seconds. That is to say, when the master and slave stations receive the GNSS signal again at the 2nd second, the slave station will sample 0.05 seconds later than the master station. In this way, there is an error of 0.05 seconds between the master and slave stations, and the error between the two will become larger as the sampling time increases.
[0045] At this time, it is necessary to use GNSS to calibrate the main station radar and the secondary station radar, such as Figure 2As shown, continuing with the above example, when the GNSS second pulse is received again in the second second, the primary and secondary radars will perform sampling again regardless of whether they have already performed sampling. That is, for the secondary radar, even if there is still 0.05 seconds before the next sampling cycle, as long as the GNSS second pulse is received, sampling will be performed. This can ensure that the rising edge time of the frequency division signal of the primary and secondary stations is consistent with the rising edge error of the GNSS second pulse, that is, a synchronization signal is obtained, which can avoid the accumulation of errors over time to the greatest extent, thereby further improving the accuracy of the dual-station radar measurement data.
[0046] With respect to step 104, the linear time delays of the primary station radar and the secondary station radar are calculated based on the first time series of the primary station radar synchronization signal and the second time series of the secondary station radar synchronization signal.
[0047] In an embodiment of the present invention, the first time series is composed of all rising edge moments of the main station radar synchronization signal, and the second time series is composed of all rising edge moments of the secondary station radar synchronization signal; the linear delay between the main station radar and the secondary station radar is calculated by the following steps: calculating the fixed delay between the first time series and the second time series; performing a linear fitting calculation on the fixed delay to obtain the linear delay.
[0048] Specifically, the local clock is used as the timer to collect the rising edge of each synchronization signal as a time series. The master and slave stations record the rising edge time series of the synchronization signal respectively. The first time series of the master station is T m (k), the second time series of the secondary station is T s (k), where k ranges from 0 to N, and N is the number of pulses of the synchronization signal during the operation of the dual-station system.
[0049] The fixed delay T between the primary and secondary stations is calculated by the following formula delta (k):
[0050] T delta (k) = T s (k)-T m (k)
[0051] Then, for a fixed delay T of length N delta (k) Perform a least squares linear fit to obtain the linear time delay T shown in the following formula: fix (k):
[0052] T fix (k) = P1*k+P2
[0053] Where P1 is the linear fitting term; P2 is the linear fitting constant term.
[0054] With respect to step 106, the linear time delay is used to correct the initial echo sequence acquired by the secondary station radar to obtain a final echo sequence that meets the synchronous sampling requirement.
[0055] In an embodiment of the present invention, the final echo sequence is obtained by the following steps: performing difference calculation on the second time series and the linear time delay to obtain an estimated time series of the secondary station radar synchronization signal; performing difference calculation on the estimated time series and the sampling period of the secondary station radar synchronization signal to obtain a time correction value; and using the time correction value to correct the initial echo sequence to obtain a final echo sequence that meets the synchronous sampling requirements.
[0056] Specifically, the estimated time series T of the secondary station is calculated by the following formula: s1 (k):
[0057] T s1 (k) = T s (k)-T fix (k)
[0058] Where, T s (k) is the second time series; T fix (k) is the linear delay.
[0059] Furthermore, the time correction value T for correcting the echo sequence is calculated by the following formula: fix1 :
[0060] T fix1 =T s1 (k)-T prf
[0061] Where, T prf is the sampling period of the secondary station radar synchronization signal.
[0062] Furthermore, the echo sequence collected by the secondary station is corrected according to the estimated time sequence. The echo sequence collected by the secondary station is S0(k, t). Due to the jitter of the GNSS signal, S0(k, t) is a non-uniform sampling sequence. s1 (k) Correct the echo sequence and convert the S0(k,t) sequence into a corrected time T fix1 After correction, the final uniformly sampled echo sequence S1(k, t) is obtained.
[0063] The final echo sequence is calculated by the following formula:
[0064] S1(k,t)=S0(k,t+T fix1 )
[0065] Through the above method, the final echo sequence that meets the synchronous sampling requirements can be obtained and used in subsequent processing procedures.
[0066] like Figure 3 , Figure 4 As shown, an embodiment of the present invention provides a time synchronization processing device for an airborne dual-station radar measurement system. The device embodiment can be implemented by software, or by hardware or a combination of software and hardware. From the hardware level, Figure 3 FIG. 1 is a hardware architecture diagram of an electronic device where a time synchronization processing device of an airborne dual-station radar measurement system provided by an embodiment of the present invention is located. Figure 3 In addition to the processor, memory, network interface, and non-volatile memory shown, the electronic device in the embodiment may also include other hardware, such as a forwarding chip responsible for processing messages, etc. Taking software implementation as an example, Figure 4 As shown, as a device in a logical sense, the CPU of the electronic device in which it is located reads the corresponding computer program in the non-volatile memory into the internal memory and runs it. This embodiment provides a time synchronization processing device for an airborne dual-station radar measurement system, including:
[0067] The first processing module 400 is used to perform frequency division processing on the local clocks of the primary and secondary radar stations, and sequentially obtain the frequency division signals of the primary and secondary radar stations that satisfy the GNSS second pulse period being an integer multiple of the frequency division signal period;
[0068] The second processing module 402 is used to perform sampling and synchronization processing on the frequency division signals of the primary and secondary radars according to the first rising edge time of the received GNSS second pulse, so as to obtain the primary and secondary radar synchronization signals whose rising edge time has the same error as the first rising edge time;
[0069] A calculation module 404 is used to calculate the linear time delay of the primary station radar and the secondary station radar according to the first time series of the primary station radar synchronization signal and the second time series of the secondary station radar synchronization signal;
[0070] The correction module 406 is used to use the linear time delay to correct the initial echo sequence collected by the secondary station radar to obtain a final echo sequence that meets the synchronous sampling requirements.
[0071] In an embodiment of the present invention, the first time series is composed of all rising edge moments of the primary station radar synchronization signal; and the second time series is composed of all rising edge moments of the secondary station radar synchronization signal.
[0072] In an embodiment of the present invention, the calculation module calculates the linear delay of the main station radar and the secondary station radar according to the first time series of the main station radar synchronization signal and the second time series of the secondary station radar synchronization signal, and is specifically used to perform the following operations: calculate the fixed delay between the first time series and the second time series; perform linear fitting calculation on the fixed delay to obtain the linear delay.
[0073] In the embodiment of the present invention, the linear delay is calculated by the following formula:
[0074] T fix (k) = P1*k+P2
[0075] Wherein, Tfix(k) is the linear time delay; P1 is the linear fitting first-order term; P2 is the linear fitting constant term; k = 0, 1, ..., N, N is the number of pulses of the synchronization signal during the operation of the dual-station radar system.
[0076] In an embodiment of the present invention, when the correction module uses the linear time delay to correct the initial echo sequence collected by the secondary station radar to obtain a final echo sequence that meets the synchronous sampling requirements, it is specifically used to perform the following operations: performing a difference calculation on the second time series and the linear time delay to obtain an estimated time series of the secondary station radar synchronization signal; performing a difference calculation on the estimated time series and the sampling period of the secondary station radar synchronization signal to obtain a time correction value; and using the time correction value to correct the initial echo sequence to obtain a final echo sequence that meets the synchronous sampling requirements.
[0077] In the embodiment of the present invention, the final echo sequence is calculated by the following formula:
[0078] T s1 (k) = T s (k)-T fix (k)
[0079] T fix1 =T s1 (k)-T prf
[0080] S1(k,t)=S0(k,t+T fix1 )
[0081] Where, T s (k) is the second time series; T fix (k) is the linear delay; T s1 (k) is the estimated time series; T prf is the sampling period of the secondary station radar synchronization signal; T fix1is the time correction value; S0(k,t) is the initial echo sequence; S1(k,t) is the final echo sequence; k = 0, 1, ..., N, N is the number of pulses of the synchronization signal during the operation of the dual-station radar system.
[0082] It is to be understood that the structure illustrated in the embodiment of the present invention does not constitute a specific limitation on the time synchronization processing device of an airborne bistatic radar measurement system. In other embodiments of the present invention, a time synchronization processing device of an airborne bistatic radar measurement system may include more or fewer components than shown in the figure, or combine some components, or split some components, or arrange the components differently. The components shown in the figure may be implemented in hardware, software, or a combination of software and hardware.
[0083] The information interaction, execution process and other contents between the modules in the above-mentioned device are based on the same concept as the embodiment of the method of the present invention. For specific contents, please refer to the description in the embodiment of the method of the present invention, and no further description is given here.
[0084] An embodiment of the present invention further provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, a time synchronization processing method for an airborne dual-station radar measurement system in any embodiment of the present invention is implemented.
[0085] An embodiment of the present invention further provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the processor executes a time synchronization processing method for an airborne dual-station radar measurement system in any embodiment of the present invention.
[0086] Specifically, a system or device equipped with a storage medium can be provided, on which software program code that implements the functions of any of the above-mentioned embodiments is stored, and a computer (or CPU or MPU) of the system or device can be enabled to read and execute the program code stored in the storage medium.
[0087] In this case, the program code itself read from the storage medium can realize the function of any one of the above-mentioned embodiments, and thus the program code and the storage medium storing the program code constitute a part of the present invention.
[0088] The storage medium embodiments for providing the program code include a floppy disk, a hard disk, a magneto-optical disk, an optical disk (such as CD-ROM, CD-R, CD-RW, DVD-ROM, DVD-RAM, DVD-RW, DVD+RW), a magnetic tape, a non-volatile memory card, and a ROM. Alternatively, the program code can be downloaded from a server computer by a communication network.
[0089] In addition, it should be clear that the functions of any of the above embodiments can be implemented not only by executing the program code read by the computer, but also by enabling an operating system operating on the computer to complete part or all of the actual operations based on instructions from the program code.
[0090] In addition, it can be understood that the program code read from the storage medium is written to a memory provided in an expansion board inserted into the computer or to a memory provided in an expansion module connected to the computer, and then based on the instructions of the program code, a CPU installed on the expansion board or expansion module is enabled to perform part or all of the actual operations, thereby realizing the functions of any of the above-mentioned embodiments.
[0091] It should be noted that, in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical factors in the process, method, article or device including the elements.
[0092] A person of ordinary skill in the art can understand that all or part of the steps of implementing the above method embodiments can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above method embodiments; and the aforementioned storage medium includes: ROM, RAM, magnetic disk or optical disk, etc., various media that can store program codes.
[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A time synchronization processing method for an airborne dual-station radar measurement system, characterized in that: include: The local clocks of the primary and secondary radar stations are frequency-divided to obtain the frequency-divided signals of the primary and secondary radar stations in turn, which satisfy the requirement that the GNSS pulse-per-second period is an integer multiple of the frequency-divided signal period. According to the first rising edge time of the received GNSS second pulse, the frequency division signals of the primary and secondary radars are sampled and synchronously processed to obtain the primary and secondary radar synchronization signals whose rising edge time is the same as the error of the first rising edge time; The linear time delay between the main station radar and the secondary station radar is calculated according to the first time series of the main station radar synchronization signal and the second time series of the secondary station radar synchronization signal; The linear time delay is used to correct the initial echo sequence collected by the secondary station radar to obtain a final echo sequence that meets the synchronous sampling requirements.
2. The method according to claim 1, characterized in that The first time series is composed of all rising edge moments of the master station radar synchronization signal.
3. The method according to claim 1, characterized in that The second time series is composed of all rising edge moments of the secondary station radar synchronization signal.
4. The method according to claim 2 or 3, characterized in that: The method of calculating the linear time delay of the main station radar and the secondary station radar according to the first time series of the main station radar synchronization signal and the second time series of the secondary station radar synchronization signal includes: Calculating a fixed time delay between the first time series and the second time series; Perform a linear fitting calculation on the fixed time delay to obtain the linear time delay.
5. The method according to claim 4, characterized in that The linear delay is calculated by the following formula: T fix (k)=P1*k+P2 Wherein, Tfix(k) is the linear time delay; P1 is the linear fitting first-order term; P2 is the linear fitting constant term; k = 0, 1, ..., N, N is the number of pulses of the synchronization signal during the operation of the dual-station radar system.
6. The method according to claim 4, characterized in that The method of using the linear time delay to correct the initial echo sequence acquired by the secondary station radar to obtain a final echo sequence that meets the synchronous sampling requirements includes: Performing difference calculation on the second time series and the linear time delay to obtain an estimated time series of the secondary station radar synchronization signal; Performing difference calculation on the estimated time series and the sampling period of the secondary station radar synchronization signal to obtain a time correction value; The initial echo sequence is corrected using the time correction value to obtain a final echo sequence that meets the synchronous sampling requirement.
7. The method according to claim 6, characterized in that The final echo sequence is calculated by the following formula: T s1 (k)=T s (k)-T fix (k) T fix1 =T s1 (k)-T prf S1(k,t)=S0(k,t+T fix1 ) Where, T s (k) is the second time series; T fix (k) is the linear delay; T s1 (k) is the estimated time series; T prf is the sampling period of the secondary station radar synchronization signal; T fix1 is the time correction value; S0(k,t) is the initial echo sequence; S1(k,t) is the final echo sequence; k = 0, 1, ..., N, N is the number of pulses of the synchronization signal during the operation of the dual-station radar system.
8. A time synchronization processing device for an airborne dual-station radar measurement system, characterized in that: include: The first processing module is used to perform frequency division processing on the local clocks of the primary and secondary radar stations, and obtain the frequency division signals of the primary and secondary radar stations in turn so that the GNSS pulse-period is an integer multiple of the frequency division signal period; The second processing module is used to sample and synchronize the frequency division signals of the primary and secondary radar stations according to the first rising edge time of the received GNSS second pulse, so as to obtain the primary and secondary radar synchronization signals whose rising edge time has the same error as the first rising edge time; A calculation module, used for calculating the linear time delay of the main station radar and the secondary station radar according to the first time series of the main station radar synchronization signal and the second time series of the secondary station radar synchronization signal; The correction module is used to use the linear time delay to correct the initial echo sequence collected by the secondary station radar to obtain a final echo sequence that meets the synchronous sampling requirements.
9. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and when the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.
10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed in a computer, the computer is caused to execute the method according to any one of claims 1 to 7.