Digital radar multi-source pulse signal sorting and parameter measuring method and system

Abstract

The invention discloses a digital radar multi-source pulse signal sorting and parameter measuring method and system, and the method comprises the steps: traversing all sampling points, and obtaining and recording upper and lower edges again according to an amplitude judgment threshold; taking the recorded rising edge as a TOA (Time Of Arrival), carrying out signal sorting on a TOA signal, obtaining a PRIM (Physical Random Instrument Module), carrying out sequence retrieval, and extracting a retrieved target pulse string; traversing the target pulse string to calculate and record a first pulse width, and after traversing is completed, acquiring a measurement parameter of the pulse signal; traversing the target pulse string again to calculate a second pulse width, intercepting a pulse of which the difference between the second pulse width and the first pulse width corresponding to the second pulse width is smaller than the first pulse width, and acquiring a carrier frequency and a broadband according to all intercepted pulses as frequency domain parameters; and taking the residual pulse string after the target pulse string is extracted from the pulse signal as a new signal input, repeating the previous steps, and when a cycle exit condition is satisfied, exiting the cycle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of radar signal processing, in particular to a digital radar multi-source pulse signal sorting and parameter measurement method and system thereof. BACKGROUND

[0002] In the development process of radar, in order to save cost, software simulation of radar characteristics is usually used for simulation research. With the improvement of computer computing power, digital radar simulation has gradually become a mainstream radar research method. In a complex electronic warfare environment, the passive radar usually receives dense, mixed and overlapped pulse trains emitted by multiple radars. The prior art generally uses envelope detectors and threshold detection methods to measure time domain parameters such as time of arrival and pulse width, and uses multi-channel correlators to measure frequency domain parameters such as carrier frequency and bandwidth. However, for parameter measurement in digital radar simulation, the methods currently used mostly only process single radar signals. For multi-source radar pulse signals, due to different parameters, the pulses will overlap, especially for the three parameters of pulse width, bandwidth and carrier frequency, which will have a great impact. If only single signals are used for parameter measurement, there is a high probability that the measured time and frequency domain parameters will be inaccurate, which will affect the subsequent processing process. SUMMARY

[0003] The present application provides a digital radar multi-source pulse signal sorting and parameter measurement method and system, which solves the problem of inaccurate measurement of time and frequency domain parameters when processing multi-source radar signals in the prior art.

[0004] The specific technical solutions are as follows: In a first aspect, the present application provides a digital radar multi-source pulse signal sorting and parameter measurement method, comprising: S1, setting an amplitude determination threshold, and setting the flags of all rising edges in the digital radar multi-source pulse signal to 1, traversing all sampling points of the pulse signal, reacquiring and recording the rising edges and falling edges according to the amplitude determination threshold, and setting the flag of the rising edge to 0 and the flag of the falling edge to 1; S2, taking the recorded rising edges as the pulse arrival time TOA, and performing signal sorting on the TOA signal based on a modified PRI transform algorithm, wherein the maximum value in the PRI transform spectrum is obtained, and if it exceeds a judgment threshold value, the maximum value is defined as PRIM, sequence retrieval is performed based on the PRIM, and the retrieved target pulse train is extracted; S3, traversing all signals of the target pulse train, reacquiring and recording the rising edges and falling edges according to the amplitude determination threshold, calculating and recording the first pulse width, and when the traversal is completed, obtaining the mode of all the first pulse widths, and taking the mode as the measurement parameter of the pulse signal ; S4, reiterating step S3 to traverse all signals of the target pulse train, calculating a second pulse width, and intercepting pulses whose second pulse width differs from their corresponding first pulse width by less than a pulse frequency and a wideband according to the intercepted pulses using a digital instantaneous frequency measurement method, as the frequency domain parameters of the pulse signal; S5, taking the remaining pulse train after the pulse signal extracts the target pulse train as a new signal input, repeating steps S1-S4, and if the number of extracted TOAs is less than a preset threshold, or there is no valid PRI, or valid measurement parameters cannot be extracted, then exiting the loop.

[0005] In some embodiments of the present application, the reacquisition and recording of rising edges and falling edges according to the amplitude determination threshold specifically includes: if the amplitude of a sampling point is greater than the amplitude determination threshold and the flag is 1, then recording the subscript of the sampling point as a rising edge, and if the amplitudes of two consecutive sampling points are less than the amplitude determination threshold, then recording the subscript of the current sampling point as a falling edge.

[0006] In some embodiments of the present application, the modified PRI transform algorithm includes: dividing the estimated IPR range into a plurality of PRI transform bins; calculating a PRI transform spectrum and an autocorrelation coefficient for all PRI transform bins within the jitter range of the change bin, and the calculation formula is as follows: ; ; wherein, represents the TOA of the i th pulse; represents the TOA of the i th pulse; represents the length of the pulse sequence; represents the time interval between the i th pulse and the i th pulse, ; is an impact signal function; is an exponential function; is an imaginary unit; calculating the determination threshold value, and the calculation formula is as follows: ; ; ; ; ; ; ;​​ in, Indicates the first The length of each PRI converter box; Indicates the amount of jitter; Indicates the first The time interval between each PRI converter box; Indicates the first PRI transform spectrum of a PRI transform box The absolute value; Indicates the observation time; , , All parameters are adjustable. , , ; Indicates the first The autocorrelation coefficients of each PRI transform box; Indicates pulse current density; Indicates the first The judgment threshold value of each PRI converter box; Based on the judgment threshold and the PRI transform spectrum, determine whether the pulse follows the PRI corresponding to the PRI transform box. Then it is determined that the group of pulses follows the first... The PRI corresponding to the PRI transformation box must be specified; otherwise, it is determined that the PRI is not followed.

[0007] In some embodiments of this application, the modified PRI transform algorithm employs overlapping PRI transform bins and a variable time starting point. Specifically, determining whether to update the time starting point by calculating the initial phase value includes: The initial phase value was calculated. The calculation formula is as follows: ; in, Indicates the first TOA of one pulse, Indicates the current starting point of time. This indicates the size of the PRI corresponding to each point in the PRI transformation box; Initial phase value The decomposition is performed, and the specific decomposition formula is as follows: ; like and ,or and Then update the starting time, let Otherwise, the starting time will not be updated; among them, Indicates the first TOA of a pulse, is constant.

[0008] In some embodiments of the present application, the change box jitter range is wherein, represents the jitter amount.

[0009] In some embodiments of the present application, the sequence retrieval is performed based on the PRIM, and the retrieved pulse train is extracted, specifically comprising: The PRI jitter range is calculated according to the PRIM, and the calculation formula is as follows: ; ; wherein, represents the jitter amount; represents the PRI maximum value, represents the PRI minimum value, i.e. the PRI jitter range is ; All TOA signals of the pulse signal are traversed, starting from the starting position of the TOA sequence, and the adjacent two items are sequentially subtracted, if the difference is within the PRI jitter range, the current two TOA time points are extracted, and when the traversal is completed, all extracted TOA time points are recorded. According to the recorded TOA time points, the pulse signal is indexed, and the corresponding target pulse train is extracted.

[0010] In some embodiments of the present application, the carrier frequency and wideband are obtained by using the digital instantaneous frequency measurement method according to all intercepted pulses, specifically comprising: The corresponding corrected signal frequency is calculated according to all intercepted pulses, and the calculation formula is as follows: ; ; wherein, is the signal expression of the intercepted pulse; is an exponential function; is a signal frequency; is a signal phase; Let wherein, is an imaginary unit, then ; Take wherein, is a sampling rate, then ; Since , and , the corrected signal frequency is for: ; The instantaneous frequency sequence is obtained based on all the calculated corrected signal frequencies; The carrier frequency is obtained based on the instantaneous frequency sequence, and the frequency distribution is obtained by performing spectral analysis on the instantaneous frequency sequence. The broadband is then obtained based on the frequency distribution.

[0011] In some embodiments of this application, obtaining the carrier frequency based on the instantaneous frequency sequence specifically includes: averaging the instantaneous frequency sequence to obtain the carrier frequency; or, The step of obtaining the carrier frequency based on the instantaneous frequency sequence specifically includes: using a spectrum analysis method to determine the frequency points of energy concentration, and using the frequency points of energy concentration as the carrier frequency.

[0012] In some embodiments of this application, the step of performing spectral analysis on the instantaneous frequency sequence to obtain the frequency distribution specifically includes: using a Fast Fourier Transform (FFT) to convert the instantaneous frequency sequence in the time domain to the frequency domain to obtain the frequency distribution.

[0013] Secondly, embodiments of this application provide a digital radar multi-source pulse signal sorting and parameter measurement system, including: The rising and falling edge acquisition module is used to set the amplitude determination threshold, set the flag of all rising edges in the digital radar multi-source pulse signal to 1, traverse all sampling points of the pulse signal, reacquire and record the rising and falling edges according to the amplitude determination threshold, and set the flag of the rising edge to 0 and the flag of the falling edge to 1. The signal sorting module is used to take the recorded rising edge as the pulse arrival time TOA, and to sort the TOA signal based on the modified PRI transform algorithm. Specifically, the maximum value in the PRI transform spectrum is obtained. If it exceeds the judgment threshold, the maximum value is defined as PRIM. Sequence retrieval is performed based on PRIM, and the retrieved target pulse train is extracted. The measurement parameter acquisition module is used to traverse all signals of the target pulse train, reacquire and record the rising and falling edges according to the amplitude determination threshold, calculate and record the first pulse width, and after traversal, obtain the mode of all the first pulse widths and use the mode as the measurement parameter of the pulse signal. ; The frequency domain parameter acquisition module is used to re-traverse all signals of the target pulse train, re-acquire and record the rising and falling edges according to the amplitude determination threshold, calculate the second pulse width, and truncate the second pulse width to a value less than the difference between the second pulse width and its corresponding first pulse width. the carrier frequency and the wideband are obtained by using the digital instantaneous frequency measurement method according to all the intercepted pulses, as the frequency domain parameters of the pulse signal; The cycle creating and exiting module is used for inputting the remaining pulse train after the target pulse train is extracted from the pulse signal into the up and down edge obtaining module as a new signal, repeating the signal sorting and frequency domain parameter obtaining steps, and exiting the cycle if the number of extracted TOAs is less than a preset threshold, or there is no valid PRI, or valid measurement parameters cannot be extracted.

[0014] The beneficial effects of the embodiment of the application are as follows: The digital radar multi-source pulse signal sorting and parameter measurement method can be applied to digital passive radar signals in a multi-source complex environment, solves the problem that the time and frequency domain parameters cannot be accurately measured when the existing technology processes multi-source radar signals, has certain stability, reduces the manual participation degree in the signal processing process of the existing classic algorithm, enables the system to automatically extract signals and calculate parameters, and the extracted signals and parameters can be used as the subsequent processing conditions of the digital radar signal, and have certain authenticity. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the application or the prior art, the drawings needed to be used in the embodiment or the prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0016] Figure 1 A flowchart of a digital radar multi-source pulse signal sorting and parameter measurement method provided by the embodiment of the application is shown in the figure. Figure 2 A composition block diagram of a digital radar multi-source pulse signal sorting and parameter measurement system provided by the embodiment of the application is shown in the figure. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the application will be described clearly and completely in combination with the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, not all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the application.

[0018] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in the case of no conflict. The terms "comprising" and "having" and any variations thereof in the embodiments of the present application and the drawings are intended to cover non-exclusive inclusion. For example, the processes, methods, systems, products or devices including a series of steps or units are not limited to the listed steps or units, but can optionally further include steps or units not listed or can optionally further include other steps or units inherent to these processes, methods, products or devices.

[0019] The embodiments of the present application disclose a digital radar multi-source pulse signal sorting and parameter measurement method. The following will be described in detail respectively.

[0020] The digital radar multi-source pulse signal sorting and parameter measurement method comprises the following steps: S1, setting an amplitude determination threshold, and setting the flags of all rising edges in the digital radar multi-source pulse signal to 1, traversing all sampling points of the pulse signal, reacquiring and recording the rising edges and falling edges according to the amplitude determination threshold, and setting the flag of the rising edge to 0 and the flag of the falling edge to 1.

[0021] Wherein, the pulse signal is a short name of the digital radar multi-source pulse signal. The rising edge refers to the moment when the signal changes from low level to high level; the falling edge refers to the moment when the signal changes from high level to low level. The amplitude determination threshold refers to the threshold for judging whether the signal amplitude reaches a certain standard.

[0022] In some embodiments, when traversing all sampling points of the pulse signal, if the amplitude of the sampling point is greater than the amplitude determination threshold and the flag is 1, the subscript of the sampling point is recorded as the rising edge; if the amplitudes of the two continuous sampling points are less than the amplitude determination threshold, the subscript of the current sampling point (referring to the sampling point after the two continuous sampling points) is recorded as the falling edge. Such a cycle is repeated until all sampling points are traversed. In the specific implementation process, the noise 3dB size can be set as the amplitude determination threshold.

[0023] S2, taking the recorded rising edge as the pulse arrival time TOA, performing signal sorting on the TOA signal based on the modified PRI transform algorithm, wherein the maximum value in the PRI transform spectrum is obtained, if it exceeds the judgment threshold value, the maximum value is defined as PRIM, sequence retrieval is performed based on PRIM, and the retrieved target pulse train is extracted.

[0024] The Time of Arrival (TOA) refers to the point in time when the pulse signal arrives at the receiver. The Pulse Repetition Interval (PRI) is the time interval between two consecutive pulses, which is an important characteristic parameter of radar signals, and different radars typically have different PRI values.

[0025] In some embodiments, the modified PRI transformation algorithm includes: The estimated IPR range is divided into several PRI transform boxes; the PRI transform spectrum is calculated for all PRI transform boxes within the jitter range of the transform boxes. and autocorrelation coefficient The calculation formula is as follows: ; ; in, Indicates the first TOA of one pulse; Indicates the first TOA of one pulse; Indicates the length of the pulse sequence; Indicates the first The pulse and the first The time interval between pulses ; For the impact signal function; It is an exponential function; It is the imaginary unit.

[0026] In the embodiments of this application, the modified PRI transform algorithm uses overlapping PRI transform boxes and a variable time start point to adapt to frequency repetition jitter.

[0027] Furthermore, the determination of whether to update the time starting point is made by calculating the initial phase value, specifically including: The initial phase value was calculated. The calculation formula is as follows: ; in, Indicates the first TOA of one pulse, Indicates the current starting point of time. This indicates the size of the PRI corresponding to each point in the PRI transformation box; Initial phase value The decomposition is performed, and the specific decomposition formula is as follows: ; like and or and , then update the time origin, let , otherwise, do not update the time origin; wherein, represents the TOA of the th pulse; is a constant, usually taking the value of 0.01.

[0028] In addition, the jitter range of the variation box in the embodiment of the present application is calculated according to the jitter amount , which is specifically , wherein, represents the jitter amount, represents the time interval between the th pulse and the th pulse.

[0029] The PRI transform spectrum and the autocorrelation coefficient of each PRI transform box are calculated, and then the judgment threshold value is calculated, and the calculation formula is as follows: ; ; ; ; ; wherein, represents the length of the th PRI transform box; represents the jitter amount; represents the time interval of the th PRI transform box; represents the absolute value of the PRI transform spectrum of the th PRI transform box; represents the observation time; , , are all adjustable parameters, , , ; represents the autocorrelation coefficient of the th PRI transform box; represents the pulse flow density; represents the judgment threshold value of the th PRI transform box.

[0030] According to the judgment threshold value and the PRI transform spectrum, it is judged whether the pulse follows the PRI corresponding to the PRI transform box, in detail, for the PRI transform spectrum corresponding to the th PRI transform box, if the absolute value of the PRI transform spectrum is greater than the judgment threshold value, it is determined that the pulse does not follow the PRI corresponding to the PRI transform box; otherwise, it is determined that the pulse follows the PRI corresponding to the PRI transform box. If , it is determined that the group of pulses follows the PRI corresponding to the PRI transform box, indicating that the group of pulses has a pulse repetition law matching the characteristics represented by the PRI transform box, otherwise it is determined not to follow.

[0031] The present application sorts the pulses by the PRI transform box according to the PRI corresponding to the PRI transform box, which can effectively separate the signals of different radars from a complex pulse signal environment, providing a basis for subsequent signal processing and analysis.

[0032] In other embodiments, sequence retrieval is performed based on PRIM, and the retrieved pulse train is extracted, specifically including: According to the PRIM, the PRI jitter range is calculated, and all PRIs in the PRI jitter range are determined to satisfy the condition to solve the problem of frequency jitter in the actual collected signal, in detail, the calculation formula of the maximum and minimum PRI values is as follows: ; ; Wherein, represents the jitter amount; represents the maximum PRI value, represents the minimum PRI value, that is, the PRI jitter range is ; All TOA signals of the pulse signal are traversed, starting from the starting position of the TOA sequence, and the adjacent two items are sequentially subtracted, if the difference is within the PRI jitter range, the current two TOA times are extracted, and when the traversal is completed, all extracted TOA times are recorded; According to the recorded TOA times, the pulse signal is indexed, and the corresponding target pulse train is extracted.

[0033] S3, traverse all signals of the target pulse train, reacquire and record the rising edge and the falling edge according to the amplitude determination threshold, calculate and record the first pulse width, when the traversal is completed, the mode of all first pulse widths is obtained, and the mode is taken as the measurement parameter of the pulse signal .

[0034] Specifically, as in step S1, the rising and falling edges of the retrieved target pulse train are taken again, and at each time the falling edge is taken, the corresponding time of the falling edge is subtracted from the last collected rising edge time, so as to obtain the first pulse width and record it. After traversing all signals, the mode of all obtained first pulse widths is taken as the measurement parameter of the pulse signal .

[0035] ​S4, traversing all signals of the target pulse train again, calculating a second pulse width, and intercepting pulses whose second pulse width differs from their corresponding first pulse width by less than According to all intercepted pulses, the carrier frequency and the wideband are obtained by using a digital instantaneous frequency measurement method as frequency domain parameters of the pulse signal.

[0036] The application is based on the measurement parameters obtained in step S3 The pulse signal is preliminarily screened to solve the problem of multiple pulse aliasing in the collected signal.

[0037] In some embodiments, according to all intercepted pulses, the carrier frequency and the wideband are obtained by using a digital instantaneous frequency measurement method (DIFM), specifically including: According to all intercepted pulses, the corresponding corrected signal frequency is calculated, and the calculation formula is as follows: ; ; Wherein, is the signal expression of the intercepted pulse; is an exponential function; is a signal frequency; is a signal phase; Let , wherein, is an imaginary unit, then , and ; ; Take , wherein, is a sampling rate, then ; Since , and , the corrected signal frequency is: ; According to all corrected signal frequencies obtained by calculation, an instantaneous frequency sequence is obtained; According to the instantaneous frequency sequence, the carrier frequency is obtained, and the frequency distribution is obtained by performing spectrum analysis on the instantaneous frequency sequence, and the wideband is obtained according to the frequency distribution.

[0038] In the specific implementation process, the average value of the instantaneous frequency sequence can be obtained to obtain the carrier frequency; or the energy concentrated frequency point can be determined by using the spectrum analysis method, and the energy concentrated frequency point is taken as the carrier frequency. In addition, the instantaneous frequency sequence in the time domain can be converted to the frequency domain by using the fast Fourier transform (FFT) to obtain the frequency distribution.

[0039] S5, the remaining pulse train after extracting the target pulse train of the pulse signal as a new signal input, repeating steps S1-S4, if the number of extracted TOA is less than the preset threshold, or there is no effective PRI, or the effective measurement parameter cannot be extracted, the loop is exited.

[0040] The above is an introduction to each step of the digital radar multi-source pulse signal sorting and parameter measurement method provided by the embodiment. Next, the overall process of a specific embodiment of a digital radar multi-source pulse signal sorting and parameter measurement method will be described in detail. Figure 1 The overall process of a specific embodiment of a digital radar multi-source pulse signal sorting and parameter measurement method will be described in detail.

[0041] Step S110: Collecting signals.

[0042] That is, collecting digital radar multi-source pulse signals that need to be sorted and measured.

[0043] Step S120: Rising and falling edge and TOA detection.

[0044] Set the noise 3dB size as the amplitude determination threshold, and set the flags of all rising edges in the collected digital radar multi-source pulse signal to 1. Then, traverse all sample points in the pulse signal, if the amplitude of a sample point is greater than the set amplitude determination threshold and the flag is 1, record the index of the current point as a rising edge, and set the flag of the rising edge to 0, and if the amplitudes of two consecutive sample points are less than the set amplitude determination threshold, record the index of the current point as a falling edge, and set the flag of the falling edge to 1. Such a cycle is repeated until all sample points are traversed, thereby obtaining all rising edges and falling edges in the pulse signal. Then, record all rising edges as TOA.

[0045] Step S130: Determine whether the number of TOA is less than 3.

[0046] Set the preset threshold to 3. Determine whether the number of TOA obtained in step S120 is less than 3, if less, end the process; if not less, go to step S140 from step S130.

[0047] Step S140: Signal sorting.

[0048] Signal sorting of the TOA signal based on the modified PRI transformation algorithm.

[0049] Step S150: No effective PRI.

[0050] Determine whether there is a pulse following the PRI corresponding to the PRI transformation bin after signal sorting in step S140, if not, i.e. no effective PRI, end the process; if yes, i.e. there is an effective PRI, go to step S160 from step S150.

[0051] Step S160: sequence search.

[0052] Taking the maximum value in the PRI transform spectrum obtained in step S140, if the value exceeds the judgment threshold value calculated in the modified PRI transform algorithm, the PRI size at which the value is located is recorded as PRIM. Sequence search is performed based on PRIM, and the searched target pulse train is extracted.

[0053] Step S170: pulse width measurement.

[0054] After step S160, all signals of the target pulse train are traversed first, the rising edge and the falling edge are re-acquired and recorded according to the amplitude determination threshold, the first pulse width is calculated and recorded, when the traversal is completed, the mode of all the first pulse widths is acquired, and the mode is taken as the measurement parameter of the pulse signal . All signals of the target pulse train are traversed again, the rising edge and the falling edge are re-acquired and recorded according to the amplitude determination threshold, the second pulse width is calculated, and the pulses whose second pulse width and corresponding first pulse width differ by less than are intercepted.

[0055] Step S180: no effective pulse width.

[0056] It is judged whether there is an effective measurement parameter that can be extracted in step S170, if there is no effective pulse width, step S180 enters step S190; if an effective pulse width is extracted, step S180 returns to step S120, the remaining pulse train after extraction is taken as a new input signal, and the above steps are repeated for the next round of signal sorting and parameter measurement.

[0057] Step S190: carrier frequency and bandwidth acquisition.

[0058] The carrier frequency and the bandwidth of all the pulses intercepted in step S170 are acquired by using a digital instantaneous frequency measurement method, as the frequency domain parameters of the pulse signal, and the process is ended.

[0059] Corresponding to the method embodiments described above, the embodiments of the present application also provide a digital radar multi-source pulse signal sorting and parameter measurement system for executing the steps of the digital radar multi-source pulse signal sorting and parameter measurement method in the above embodiments. As shown in Figure 2 , the digital radar multi-source pulse signal sorting and parameter measurement system 200 includes an upper and lower edge acquisition module 210, a signal sorting module 220, a measurement parameter acquisition module 230, a frequency domain parameter acquisition module 240, and a loop creation and exit module 250.

[0060] Specifically, the up-down edge obtaining module 210 is configured to set an amplitude determination threshold, set the flag of all rising edges in the digital radar multi-source pulse signal to 1, traverse all sampling points of the pulse signal, re-obtain and record rising edges and falling edges according to the amplitude determination threshold, set the flag of the rising edges to 0, and set the flag of the falling edges to 1.

[0061] The signal sorting module 220 is configured to take the recorded rising edges as pulse arrival time TOA, perform signal sorting on the TOA signal based on a modified PRI transform algorithm, obtain a maximum value in a PRI transform spectrum, define the maximum value as a PRI M if the maximum value exceeds a judgment threshold, perform sequence retrieval based on the PRI M, and extract a target pulse train retrieved.

[0062] The measurement parameter obtaining module 230 is configured to traverse all signals of the target pulse train, re-obtain and record rising edges and falling edges according to the amplitude determination threshold, calculate and record a first pulse width, obtain a mode of all first pulse widths after the traversal is completed, and take the mode as a measurement parameter of the pulse signal. .

[0063] The frequency domain parameter obtaining module 240 is configured to traverse all signals of the target pulse train again, re-obtain and record rising edges and falling edges according to the amplitude determination threshold, calculate a second pulse width, and intercept pulses whose second pulse width and corresponding first pulse width differ by less than a preset threshold, obtain a carrier frequency and a wideband using a digital instantaneous frequency measurement method based on all the intercepted pulses, and take the carrier frequency and the wideband as frequency domain parameters of the pulse signal.

[0064] The cycle creating and exiting module 250 is configured to take the remaining pulse train after the pulse signal extraction target pulse train as a new signal input to the up-down edge obtaining module, repeat the signal sorting and the frequency domain parameter obtaining steps, and exit the cycle if the number of extracted TOA is less than a preset threshold, or there is no valid PRI, or valid measurement parameters cannot be extracted.

[0065] In summary, the present application discloses a digital radar multi-source pulse signal sorting and parameter measurement method and system, which can be applied to digital passive radar signals in a multi-source complex environment, solves the problem that time and frequency domain parameters cannot be accurately measured when processing multi-source radar signals in the prior art, has certain stability, reduces the degree of manual participation in the signal processing process of the existing classic algorithm, enables the system to automatically extract signals and calculate parameters, and the extracted signals and parameters can be used as subsequent processing conditions for digital radar signals and have certain authenticity.

[0066] Those skilled in the art can understand that the modules or processes in the drawings are not necessarily required to implement the present application. ​

[0067] Those skilled in the art can understand that the modules in the device in the embodiments can be distributed in the device in the embodiments as described in the embodiments, or can be changed to be located in one or more devices different from the embodiments. The modules in the above embodiments can be combined into one module, or can be further split into multiple sub-modules.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for digital radar multi-source pulse signal sorting and parameter measurement, characterized in that, The method comprises the following steps: S1, setting an amplitude determination threshold, setting the flag of all rising edges in a digital radar multi-source pulse signal to 1, traversing all sampling points of the pulse signal, reacquiring and recording rising edges and falling edges according to the amplitude determination threshold, setting the flag of the rising edges to 0, and setting the flag of the falling edges to 1; S2, taking the recorded rising edges as pulse arrival time TOA, performing signal sorting on the TOA signal based on a modified PRI transform algorithm, wherein the maximum value in the PRI transform spectrum is obtained, if the maximum value exceeds a judgment threshold value, the maximum value is defined as PRIM, sequence retrieval is performed based on the PRIM, and the target pulse train retrieved is extracted; S3, traversing all signals of the target pulse train, reacquiring and recording rising and falling edges according to the amplitude decision threshold, calculating and recording first pulse width, when traversing is completed, acquiring mode of all the first pulse width, and taking the mode as a measurement parameter of the pulse signal ; S4, traversing all signals of the target pulse train again as in step S3, calculating a second pulse width, and intercepting pulses whose second pulse width differs from their corresponding first pulse width by less than the frequency and bandwidth of the intercepted pulses as the frequency domain parameters of the pulse signals. S5, taking the remaining pulse train after the target pulse train is extracted from the pulse signal as a new signal input, repeating steps S1-S4, and if the number of extracted TOA is less than a preset threshold, or there is no valid PRI, or valid measurement parameters cannot be extracted, the cycle is exited.

2. The method of claim 1, wherein, The reacquiring and recording of the rising edges and the falling edges according to the amplitude determination threshold specifically comprises: if the amplitude of a sampling point is greater than the amplitude determination threshold and the flag is 1, the index of the sampling point is recorded as a rising edge; and if the amplitudes of two continuous sampling points are less than the amplitude determination threshold, the index of the current sampling point is recorded as a falling edge.

3. The method of claim 1, wherein, The modified PRI transform algorithm comprises: The estimated IPR range is divided into several PRI transformation bins; all the PRI transformation bins in the jitter range of the change bin are calculated for the PRI transformation spectrum and autocorrelation coefficient The calculation formula is as follows: ； ； wherein, represents the TOA of the th pulse; represents the TOA of the th pulse; represents the length of the pulse sequence; represents the time interval between the th pulse and the th pulse, ; is an impulse signal function; is an exponential function; is the imaginary unit; The judgment threshold value is calculated, and the calculation formula is as follows: ； ； ； ； ； wherein, denotes the length of the PRI transform bin; denotes the amount of jitter; denotes the time interval of the PRI transform bin; denotes the absolute value of the PRI transform spectrum of the PRI transform bin; denotes the observation time; , , , are all adjustable parameters, , , ; denotes the autocorrelation coefficient of the PRI transform bin; denotes the pulse stream density; denotes the decision threshold value of the PRI transform bin; According to the judgment threshold value and the PRI transform spectrum, it is judged whether the pulse follows the PRI corresponding to the PRI transform box, if , it is determined that the pulse follows the PRI corresponding to the first PRI transform box, otherwise, it is determined that the pulse does not follow the PRI.

4. The method of claim 3, wherein, The modified PRI transform algorithm adopts mutually overlapped PRI transform bins and a variable time starting point, wherein whether the time starting point is updated is determined by calculating an initial phase value, and the specific process comprises: The initial phase value is calculated The calculation formula is as follows: ； wherein, represents the TOA of the th pulse, represents the current corresponding time origin, represents the PRI size corresponding to each PRI transform bin midpoint; The initial phase value is set to 0 Decomposition is performed, and the specific decomposition formula is as follows: ； If and or and , update the time origin, let , otherwise do not update the time origin; where is the TOA of the th pulse, is a constant.

5. The method of claim 3, wherein, The change box shaking range is wherein, denotes the shaking amount.

6. The method of claim 1, wherein, The sequence retrieval based on the PRIM and the extraction of the retrieved pulse train specifically comprise: The PRI jitter range is calculated according to the PRIM, and the calculation formula is as follows: ； ； wherein, represents the jitter amount; represents the PRI maximum value, represents the PRI minimum value, i.e. the PRI jitter range is ; All TOA signals of the pulse signal are traversed, subtraction operation is sequentially performed on adjacent two items from the starting position of the TOA sequence, if the difference value is located in the PRI jitter range, the current two TOA time points are extracted, and when the traversal is completed, all extracted TOA time points are recorded; The pulse signal is indexed according to the recorded TOA time points, and the corresponding target pulse train is extracted.

7. The method of claim 1, wherein, The carrier frequency and the wideband are acquired from all intercepted pulses by using a digital instantaneous frequency measurement method, and the specific process comprises: The modified signal frequency corresponding to each intercepted pulse is calculated, and the calculation formula is as follows: ； ； wherein is the signal expression for the th intercepted pulse; is an exponential function; is the signal frequency; is the signal phase; Let where is the imaginary unit, then ; Take wherein, is the sampling rate, then ; Since , and , the correction signal frequency is: ； An instantaneous frequency sequence is obtained according to all calculated modified signal frequencies; The carrier frequency is acquired according to the instantaneous frequency sequence, and the frequency distribution is obtained by performing spectrum analysis on the instantaneous frequency sequence, and the wideband is acquired according to the frequency distribution.

8. The method of claim 7, wherein, The carrier frequency is acquired according to the instantaneous frequency sequence, specifically comprising: the average value of the instantaneous frequency sequence is obtained to obtain the carrier frequency; or The carrier frequency is acquired according to the instantaneous frequency sequence, specifically comprising: the energy-concentrated frequency point is determined by using a spectrum analysis method, and the energy-concentrated frequency point is taken as the carrier frequency.

9. The method of claim 7, wherein, The frequency spectrum analysis on the instantaneous frequency sequence obtains a frequency distribution, specifically comprising: converting the instantaneous frequency sequence in time domain to frequency domain by using fast Fourier transform (FFT) to obtain the frequency distribution.

10. A digital radar multi-source pulse signal sorting and parameter measurement system, characterized in that, Comprise: The up and down edge acquisition module is configured to set an amplitude determination threshold, set the flag of all rising edges in the digital radar multi-source pulse signal as 1, traverse all sampling points of the pulse signal, reacquire and record rising edges and falling edges according to the amplitude determination threshold, set the flag of the rising edges as 0, and set the flag of the falling edges as 1; The signal sorting module is configured to take the recorded rising edges as time of arrival (TOA) of pulses, sort the TOA signal based on a modified PRI transform algorithm, obtain a maximum value in a PRI transform spectrum, define the maximum value as a PRI M if the maximum value exceeds a judgment threshold, perform sequence retrieval based on the PRI M, and extract a target pulse train retrieved; The measurement parameter acquisition module is configured to traverse all signals of the target pulse train, reacquire and record rising edges and falling edges according to the amplitude determination threshold, calculate and record first pulse widths, and after the traversal is completed, acquire a mode of all the first pulse widths and take the mode as a measurement parameter of the pulse signal ; The frequency domain parameter acquisition module is configured to traverse all signals of the target pulse train again, reacquire and record rising edges and falling edges according to the amplitude determination threshold, calculate a second pulse width, and intercept pulses whose second pulse width and corresponding first pulse width differ by less than The frequency domain parameter acquisition module is configured to traverse all signals of the target pulse train again, reacquire and record rising edges and falling edges according to the amplitude determination threshold, calculate a second pulse width, and intercept pulses whose second pulse width and corresponding first pulse width differ by less than The frequency domain parameter acquisition module is configured to traverse all signals of the target pulse train again, reacquire and record rising edges and falling edges according to the amplitude determination threshold, calculate a second pulse width, and intercept pulses whose second pulse width and corresponding first pulse width differ by less than The frequency domain parameter acquisition module is configured to traverse all signals of the target pulse train again, reacquire and record rising edges and falling edges according to the amplitude determination threshold, calculate a second pulse width, and intercept pulses whose second pulse width and corresponding first pulse width differ by The cycle creation and exit module is configured to take the remaining pulse train after the pulse signal extracts the target pulse train as a new signal, input the new signal into the up and down edge acquisition module, repeat the signal sorting and frequency domain parameter acquisition steps, and exit the cycle if the number of extracted TOAs is less than a preset threshold, or there is no valid PRI, or valid measurement parameters cannot be extracted.

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