A method and system for simulating the echo of a radar with a variable pulse repetition frequency and a variable range resolution

Abstract

The application discloses a kind of to heavy frequency unevenly resolving distance ambiguous radar echo simulation method and system, belong to radar test and electronic countermeasure technical field.The application is by detecting the pulse parameter of received radar signal, calculates pulse repetition period mean;According to pulse repetition period, the modulus value of delay quantity and its pulse repetition period is calculated, obtains ambiguity quantity;To received radar signal is Doppler frequency modulation and is delayed according to ambiguity quantity processing, generates analog echo pulse signal;After digital-analog conversion and power amplification, it is transmitted.The application is by detecting pulse repetition period pulse by pulse and introducing modulus operation delay control, makes analog echo present consistent ambiguous time relationship with real target under multiple uneven pulse repetition period, solves the problem that prior art cannot accurately simulate heavy frequency unevenly resolving distance ambiguous radar echo, with the advantages of high stability, strong adaptability, easy to integrate.

Description

Technical Field

[0001] This invention relates to the fields of radar testing and electronic countermeasures technology, and more specifically, to an echo simulation method and system for range ambiguity radar with repetition rate unevenness. Background Technology

[0002] Range ambiguity resolution using staggered repetition rate (PRR) is a commonly used air-to-air radar detection technique. It involves transmitting multiple high-repetition-rate pulse trains, measuring the delay of the echoes at different pulse repetition periods, and using the Chinese remainder theorem to resolve range ambiguity, thus achieving accurate target range measurement. Testing and adversarial exercises for this type of radar require the ability to simulate the generation of single or multiple false target echo signals.

[0003] Existing echo simulation techniques mainly include active simulation based on DRFM (Radar Radar Frequency Measuring) and passive simulation based on corner reflectors. DRFM-based methods typically employ range-to-weighted or velocity-to-weighted methods, simulating moving targets by continuously relaying received radar signal samples. However, this method cannot satisfy the ambiguity relationship between frequency and time, resulting in poor controllability of the simulated target. Corner reflector-based methods, on the other hand, have extremely limited simulation range due to poor position and velocity controllability. Furthermore, existing methods are not optimized for the specific characteristics of radar systems with multiple sets of staggered pulse repetition periods, failing to establish a mathematical logic consistent with the real target in the time relationship of echo delay.

[0004] Therefore, there is an urgent need for a method and system that can stably, flexibly, and accurately simulate echoes from range-ambiguous radar with high repetition rate. Summary of the Invention

[0005] This invention aims to solve the problem that existing technologies cannot effectively, stably, and flexibly simulate echoes from radar systems using multiple sets of staggered pulse repetitive cycles. It provides an echo simulation method and system based on pulse-by-pulse delay forwarding and modulo operation delay control. To achieve the above objective, the technical solution adopted by this invention is as follows: In a first aspect, the present invention provides an echo simulation method for range ambiguity radar with repetition rate unevenness, comprising: The received radar signal is detected, and pulse parameters are extracted. The pulse parameters include at least the pulse arrival time, signal frequency, and pulse width. The average pulse repetition period is calculated by obtaining the pulse arrival time difference of M consecutive pulses of the current radar signal, and this average is used as the pulse repetition period of the current radar signal. M is a positive integer. Based on the distance of the simulated echo signal relative to the radar and the pulse repetition period, the delay and ambiguity of each simulated echo pulse of the simulated echo signal are calculated. The delay is obtained based on the ratio of the speed of light to the distance, and the ambiguity is the result of taking the delay modulo the pulse repetition period. The received radar signal is subjected to Doppler frequency modulation and delayed according to the stated delay amount to generate a simulated echo pulse signal. The generated analog echo pulse signal is converted from digital to analog and then amplified to form the transmission signal.

[0006] Furthermore, the extracted pulse parameters include: The received radar signal is amplified with low noise and converted from analog to digital before being split into two paths. The first path is used for signal detection and parameter measurement, and the second path is used for delay modulation. The pulse parameters are extracted using Fourier transform and envelope detection. The pulse parameters include pulse arrival time, signal frequency, pulse width, and pulse amplitude. Signals with similar pulse widths and resolutions within the same frequency range are subjected to pulse arrival time difference analysis, and the average pulse repetition period is statistically obtained.

[0007] Furthermore, the expression for calculating the delay of each simulated echo pulse is as follows:

[0008] in, For delay amount, Let represent the distance of the i-th simulated echo signal relative to the target, C be the speed of light, and PRI be the pulse repetition period. This represents the remainder operation of A with respect to B.

[0009] Furthermore, the Doppler frequency modulation employs complex exponential modulation, and the modulation frequency is equal to the Doppler frequency of the echo to be simulated. The delay processing is implemented using a digital delay line or a FIFO memory, and the delay amount is equal to the delay amount of each analog echo pulse.

[0010] Furthermore, the method includes: When the radar signal contains multiple sets of staggered pulse trains with different pulse repetition periods, calculate the corresponding pulse repetition period for each set of pulse trains. The delay and ambiguity are calculated based on the pulse repetition period of each group. The simulated echo pulse signal generated by the sequential generation of multiple pulse trains results in an ambiguity in the time relationship of the generated simulated echo pulse signal on each pulse train, consistent with the real target echo.

[0011] The second aspect is an echo simulation system for range-ambiguous radar with repetition rate discrepancies, comprising: The signal detection and parameter measurement module is used to detect the received radar signal, extract pulse parameters, count the pulse arrival time difference of M consecutive pulses, and calculate the average pulse repetition period as the pulse repetition period of the current radar signal; where M is a positive integer. The delay calculation module is used to calculate the delay and ambiguity of each simulated echo pulse based on the distance of the simulated echo relative to the radar and the pulse repetition period. The delay is calculated based on the ratio of the speed of light to the distance, and the ambiguity is the result of taking the delay modulo the pulse repetition period. The delay and Doppler modulation module is used to perform Doppler frequency modulation on the currently received radar signal and perform delay processing according to the delay amount to generate a simulated echo pulse signal. The digital-to-analog converter and power amplifier module is used to convert the generated analog echo pulse signal into an analog signal and amplify it before transmission.

[0012] Furthermore, the signal detection and parameter measurement module includes: a low-noise amplifier, an analog-to-digital converter, a Fourier transform unit, and a video envelope detection unit; the output of the analog-to-digital converter is divided into two paths, one of which is connected to the signal detection and parameter measurement module, and the other of which is connected to the delay and Doppler modulation module.

[0013] Furthermore, the delay calculation module is equipped with a parameter memory for storing the delay and ambiguity values ​​corresponding to multiple pulse trains with different pulse repetition periods; the delay and Doppler modulation module sequentially calls the corresponding delay values ​​for modulation according to the pulse group sequence number.

[0014] Furthermore, the system further includes amplitude modulation of the simulated echo pulse signal to simulate changes in the target radar cross-section or radar propagation loss.

[0015] Furthermore, when it is necessary to simulate multiple false signals simultaneously, the delay and Doppler modulation module generates simulated echo pulse signals corresponding to each false target, and outputs the multiple modulated signals by superimposing them.

[0016] The beneficial effects of this invention are as follows: This invention detects the pulse repetition period of radar signals pulse by pulse and accurately calculates the delay and ambiguity of each echo pulse based on analog arithmetic. This makes the simulated echo present an ambiguity time relationship that is completely consistent with the real target echo under multiple sets of staggered pulse repetition periods, thus solving the problem that existing technologies cannot perform stable and accurate echo simulation for staggered range ambiguity radar with high repetition rate.

[0017] This invention adopts a single-path delay forwarding architecture, which eliminates the need for multiple copies of radar signals and complex storage space management. It only needs to detect the pulse repetition period and implement analog operation delay control to adapt to the dynamic changes of different pulse repetition periods, which significantly improves the stability and real-time performance of the analog echo system.

[0018] This invention is based on the Digital Radio Frequency Memory (DRFM) infrastructure. It can be integrated and upgraded in the existing echo simulation system by only adding delay calculation and analog operation processing units. It is simple to implement, has low hardware resource overhead, and is easy to promote and apply in radar testing and spectrum countermeasure equipment.

[0019] This invention supports the simultaneous simulation of multiple false target echoes. The distance and velocity (Doppler frequency) of each false target can be configured independently. By calculating the delay and Doppler frequency of each false target separately and superimposing them in the digital domain, it provides a variety of flexible and controllable simulation scenarios for radar capability testing and adversarial exercises.

[0020] This invention allows for a flexible balance between the response speed of parameter measurement and the accuracy of pulse repetition period estimation by selecting the number of pulses M involved in the statistics and the calculation accuracy of the delay amount. By selecting the delay quantization step size, the resolution and range of the range simulation can be set to meet the differentiated simulation accuracy requirements of different radar systems.

[0021] All delay control and Doppler modulation in this invention are implemented based on digital logic. The control parameters can be updated in real time by software. The distance, speed and number of simulated echoes can be dynamically adjusted without hardware modification. It has high programmability and reusability.

[0022] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing embodiments of the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the method of the present invention; Figure 2 This is a schematic diagram of the system of the present invention. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0026] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0027] Example 1: Figure 1 This invention illustrates an echo simulation method for a range-ambiguous radar with varying repetition rates. The method first detects the radar signal waveform and measures its parameters (time of arrival, signal frequency, pulse width, pulse amplitude, etc.), and calculates the pulse repetition period. Based on the simulated echo distance and pulse repetition period, a delay is calculated, and this delay is modulated onto the received sample signal. After power amplification, the simulated echo signal is transmitted. Specifically, the method includes the following steps: S1. Detect the received radar signal and extract pulse parameters, which include at least pulse arrival time, signal frequency, and pulse width; calculate the average pulse repetition period by obtaining the pulse arrival time difference of M consecutive pulses of the radar signal, and use it as the pulse repetition period of the current radar signal; where M is a positive integer. Specifically, the process includes: the radar signal passes through a low-noise amplifier and then enters the ADC acquisition device. After sampling the received signal, the radio frequency signal is digitized. This digital signal is then split into two paths and fed into two modules: signal detection and parameter measurement, and delay modulation. The signal detection and parameter measurement modules utilize Fourier transform and video envelope detection to extract parameters such as pulse arrival time (TOA), signal frequency (RF), pulse width (PW), and pulse amplitude (PA). By statistically analyzing the pulse arrival time, signal frequency, and pulse width of M consecutive pulse signals, and performing pulse arrival time difference analysis on signals with similar pulse widths within the same frequency resolution, the average pulse repetition period calculated from the pulse arrival time difference is taken as the pulse repetition period (PRI) of the radar signal. The calculation formula is as follows:

[0028]

[0029] in, Let be the pulse arrival time of the m-th pulse.

[0030] S1 can accurately measure the radar pulse repetition period by differentially statistically analyzing the arrival times of M consecutive pulses, providing a precise reference for subsequent analog operation delay control and avoiding deviations in the simulated echo distance calculation caused by PRI measurement errors in the pulse repetition period.

[0031] S2. Based on the distance of the simulated echo relative to the radar and the pulse repetition period, calculate the delay and ambiguity of each simulated echo pulse. The delay is obtained based on the ratio of the speed of light to the distance, and the ambiguity is the result of taking the delay modulo the pulse repetition period. Specifically, when the distance of the i-th echo to be simulated to the radar... When the value is positive, the simulated echo is located on the extension line of the line connecting the radar and the target; otherwise, the simulated echo is located in the middle of the line connecting the radar and the target. The theoretical total delay The expression is:

[0032] The expression for calculating the delay of each simulated echo pulse is as follows:

[0033] The calculation of the ambiguity of each simulated echo pulse The expression is:

[0034] in, For delay amount, Let represent the distance of the i-th simulated echo relative to the target, C be the speed of light, and PRI be the pulse repetition period. This represents the remainder operation of A divided by B. This indicates the relative distance between the radar and the target.

[0035] S2 introduces modular arithmetic to map the delay corresponding to long distances to a single pulse repetition period, so that the simulated echo signal presents an ambiguity in time relationship consistent with the real target echo in each set of staggered pulse repetition periods, thus solving the problem that traditional methods cannot simulate the ambiguity relationship of multiple sets of pulse repetition periods.

[0036] S3. Perform Doppler frequency modulation on the currently received radar signal and perform delay processing according to the delay amount to generate a simulated echo pulse signal. Specifically, this includes: based on the simulated echo delay and Doppler frequency, the currently received radar signal... After performing Doppler frequency modulation and delay processing, the i-th analog echo signal can be obtained. The formulas for calculating Doppler frequency modulation and delay are as follows:

[0037] in, Let be the Doppler frequency of the echo signal to be simulated, and l be the l-th simulated echo pulse. The delay of the currently received radar signal is denoted by j, which is an imaginary unit, and J represents the transmitted jamming signal.

[0038] The S3 uses complex exponential modulation to accurately generate the required Doppler frequency, and can independently control the distance and velocity parameters of the simulated echo signal. Moreover, the delay resolution is only limited by the sampling rate, and it can achieve sub-meter distance simulation accuracy.

[0039] S4. The generated analog echo pulse signal is transmitted after digital-to-analog conversion and power amplification. Specifically, a DAC is used to convert the digital signal into an analog signal, which is then amplified by a power amplifier to form an analog echo signal for transmission. This completes the conversion from digital domain processing to radio frequency signal, ensuring that the power of the analog echo signal meets the dynamic range requirements of the radar receiver.

[0040] Furthermore, in some specific embodiments, when the radar signal contains multiple sets of staggered pulse trains with different pulse repetition periods, the corresponding pulse repetition period is calculated for each set of pulse trains, and the corresponding delay and ambiguity are calculated according to the pulse repetition period of each set. The simulated echo pulse signal is generated sequentially according to the group order of the pulse trains, so that the generated simulated echo pulse signal presents an ambiguous time relationship consistent with the real target echo on each set of pulse trains.

[0041] Therefore, by grouping and dynamically switching delay parameters, the simulated echo signal can be perfectly adapted to the multiple PRI working modes of the repetition rate uneven resolution range ambiguity radar. The distance calculated by the radar end using the Chinese remainder theorem is highly consistent with the preset value, thus realizing effective testing of this type of radar.

[0042] Example 2: This embodiment provides an echo simulation method for range ambiguity resolution radar with repetition rate unevenness, taking a certain radar as an example.

[0043] S1. Detect the received radar signal and extract pulse parameters, which include at least pulse arrival time, signal frequency, and pulse width; calculate the average pulse repetition period by obtaining the pulse arrival time difference of M consecutive pulses of the current radar signal, and use it as the pulse repetition period of the current radar signal; where M is a positive integer. The radar transmitted signal is amplified with low noise and then digitized by an ADC. The digital signal enters the signal detection and parameter measurement module, where Fourier transform and video envelope detection are used to extract the pulse arrival time (TOA), signal frequency (RF), pulse width (PW), and pulse amplitude (PA) of each pulse. The TOA of M=1024 consecutive pulses is statistically analyzed. For signals with similar pulse widths within the same frequency resolution, the pulse arrival time difference is calculated, and the average pulse repetition period is calculated.

[0044] In this embodiment, the target distance and Doppler frequency are 50km and 2400Hz, respectively, requiring the generation of a simulated echo signal with a relative target distance of -10km (i.e., a relative radar distance of 40km). The radar information parameters are shown in Table 1.

[0045] Table 1. Radar System Information Parameters (Multi-set Staggered Pulse Repetition Period Ranging Radar)

[0046] For the five staggered pulse trains of the radar signal shown in Table 1, the measured pulse repetition periods PRI are 39.1 and 39.1, respectively. 27.2 26.1 34.1 38.2 .

[0047] S2. Based on the distance between the simulated echo signal and the radar and the pulse repetition period, calculate the delay and ambiguity of each simulated echo pulse of the simulated echo signal. The delay is obtained based on the ratio of the speed of light to the distance, and the ambiguity is the result of taking the delay modulo the pulse repetition period. The true distance to the target can be determined from S1. =50km, distance between the simulated echo and the target =-10km (i.e., 40km relative to radar). Speed ​​of light C = 3 × 10 8 m / s. Calculate the delay. = 2×(50+(-10))×10 3 / (3×10 8 = 266.67 The fuzzy quantity is obtained by taking the modulus of each group of PRI. : For the pulse repetition period PRI=39.1 hour: =266.67 mod 39.1 = 32.66 ; For the pulse repetition period PRI=27.2 hour: =266.67 mod 27.2 = 23.66 ; For the pulse repetition period PRI=26.1 hour: =266.67 mod 26.1 = 6.66 ; For the pulse repetition period PRI=34.1 hour: =266.67 mod 34.1 = 28.66 ; For the pulse repetition period PRI=38.2 hour: =266.67 mod 38.2 = 0.66 .

[0048] S3. The currently received radar signal is subjected to Doppler frequency modulation and delayed according to the stated delay amount to generate a simulated echo pulse signal; in this embodiment, the Doppler frequency of the echo to be simulated is... =2400Hz. For each currently received pulse, complex exponential modulation is used, and a FIFO memory is used to delay according to the ambiguity of the corresponding group. The actual measured delay and Doppler frequency are shown in Table 2.

[0049] Table 2. Measurements of Delay and Doppler Frequency under Simulated Echo Conditions

[0050] S4. The generated analog echo pulse signal is converted from digital to analog and then amplified to form an analog echo signal for transmission.

[0051] In the experiment, the simulated echo relative radar distance was calculated to be 39.99 km and the Doppler frequency was 2402.8 Hz, which is highly consistent with the preset value (40 km, 2400 Hz). The distance deviation was only 0.01 km and the Doppler frequency deviation was only 2.8 Hz, which verified the accuracy and effectiveness of the invention.

[0052] Example 3: See Figure 2 An echo simulation system for range-ambiguous radar with repetition rate unevenness, comprising: The signal detection and parameter measurement module is used to detect the received radar signal, extract pulse parameters, count the pulse arrival time difference of M consecutive pulses, and calculate the average pulse repetition period as the pulse repetition period of the current radar signal; where M is a positive integer. The delay calculation module is used to calculate the delay and ambiguity of each simulated echo pulse based on the distance of the simulated echo relative to the radar and the pulse repetition period. The delay is calculated based on the ratio of the speed of light to the distance, and the ambiguity is the result of taking the delay modulo the pulse repetition period. The delay and Doppler modulation module is used to perform Doppler frequency modulation on the currently received radar signal and perform delay processing according to the delay amount to generate a simulated echo pulse signal. The digital-to-analog converter and power amplifier module is used to convert the generated analog echo pulse signal into an analog signal and amplify it before transmission.

[0053] Furthermore, the signal detection and parameter measurement module includes: a low-noise amplifier, an analog-to-digital converter, a Fourier transform unit, and a video envelope detection unit; the output of the analog-to-digital converter is divided into two paths, one of which is connected to the signal detection and parameter measurement module, and the other of which is connected to the delay and Doppler modulation module.

[0054] Furthermore, the delay calculation module is equipped with a parameter memory for storing the delay and ambiguity values ​​corresponding to multiple pulse trains with different pulse repetition periods; the delay and Doppler modulation module sequentially calls the corresponding delay values ​​for modulation according to the pulse group sequence number.

[0055] Furthermore, the system further includes amplitude modulation of the simulated echo pulse signal to simulate changes in the target radar cross-section or radar propagation loss.

[0056] Furthermore, when it is necessary to simulate multiple false signals simultaneously, the delay and Doppler modulation module generates simulated echo pulse signals corresponding to each false target, and outputs the multiple modulated signals by superimposing them.

[0057] It should be noted that the specific manner in which each module performs its operation in the apparatus described in the above embodiments has been described in detail in the embodiments of the method, and will not be elaborated here.

[0058] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0059] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for echo simulation of range ambiguity radar with repetition rate unevenness, characterized in that, include: The received radar signal is detected, and pulse parameters are extracted. The pulse parameters include at least the pulse arrival time, signal frequency, and pulse width. The average pulse repetition period is calculated by obtaining the pulse arrival time difference of M consecutive pulses of the radar signal, and is used as the pulse repetition period of the current radar signal; M is a positive integer. Based on the distance of the simulated echo signal relative to the radar and the pulse repetition period, the delay and ambiguity of each simulated echo pulse of the simulated echo signal are calculated. The delay is obtained based on the ratio of the speed of light to the distance, and the ambiguity is the result of taking the delay modulo the pulse repetition period. The received radar signal is subjected to Doppler frequency modulation and delayed according to the stated delay amount to generate a simulated echo pulse signal. The generated analog echo pulse signal is converted from digital to analog and then amplified to form an analog echo signal for transmission.

2. The echo simulation method for range ambiguity resolution radar according to claim 1, characterized in that, The extracted pulse parameters include: The received radar signal is amplified with low noise and converted from analog to digital before being split into two paths. The first path is used for signal detection and parameter measurement, and the second path is used for delay modulation. The pulse parameters are extracted using Fourier transform and envelope detection. The pulse parameters include pulse arrival time, signal frequency, pulse width, and pulse amplitude. Signals with similar pulse widths and resolutions within the same frequency range are subjected to pulse arrival time difference analysis, and the average pulse repetition period is statistically obtained.

3. The echo simulation method for range ambiguity resolution radar according to claim 2, characterized in that, The expression for calculating the delay of each simulated echo pulse is as follows: in, For delay amount, Let represent the distance of the i-th simulated echo signal relative to the target, C be the speed of light, and PRI be the pulse repetition period. This represents the remainder operation of A with respect to B.

4. The echo simulation method for range ambiguity resolution radar according to claim 1, characterized in that, The Doppler frequency modulation adopts complex exponential modulation, and the modulation frequency is equal to the Doppler frequency of the echo to be simulated. The delay processing is implemented using a digital delay line or a FIFO memory, and the delay amount is equal to the delay amount of each analog echo pulse.

5. The echo simulation method for range ambiguity resolution radar according to claim 1, characterized in that, The method includes: When the radar signal contains multiple sets of staggered pulse trains with different pulse repetition periods, calculate the corresponding pulse repetition period for each set of pulse trains. The delay and ambiguity are calculated based on the pulse repetition period of each group. The simulated echo pulse signal generated by the sequential generation of multiple pulse trains results in an ambiguity in the time relationship of the generated simulated echo pulse signal on each pulse train, consistent with the real target echo.

6. An echo simulation system for range ambiguity resolution radar with repetition rate unevenness, characterized in that, include: The signal detection and parameter measurement module is used to detect the received radar signal, extract pulse parameters, count the pulse arrival time difference of M consecutive pulses, and calculate the average pulse repetition period as the pulse repetition period of the current radar signal; where M is a positive integer. The delay calculation module is used to calculate the delay and ambiguity of each simulated echo pulse based on the distance of the simulated echo signal relative to the radar and the pulse repetition period. The delay is calculated based on the ratio of the speed of light to the distance, and the ambiguity is the result of taking the delay modulo the pulse repetition period. The delay and Doppler modulation module is used to perform Doppler frequency modulation on the currently received radar signal and perform delay processing according to the delay amount to generate a simulated echo pulse signal. The digital-to-analog converter and power amplifier module is used to convert the generated analog echo pulse signal into an analog signal and amplify it to form an analog echo signal for transmission.

7. The echo simulation system for range ambiguity resolution radar according to claim 6, characterized in that, The signal detection and parameter measurement module includes: a low-noise amplifier, an analog-to-digital converter, a Fourier transform unit, and a video envelope detection unit; the output of the analog-to-digital converter is divided into two paths, one of which is connected to the signal detection and parameter measurement module, and the other of which is connected to the delay and Doppler modulation module.

8. The echo simulation system for range ambiguity resolution radar according to claim 6, characterized in that, The delay calculation module is equipped with a parameter memory, which is used to store the delay and ambiguity values ​​corresponding to multiple pulse trains with different pulse repetition periods. The delay and Doppler modulation module calls the corresponding delay values ​​for modulation in sequence according to the pulse group number.

9. The echo simulation system for range ambiguity resolution radar according to claim 6, characterized in that, The system further includes amplitude modulation of the simulated echo pulse signal to simulate changes in the target radar cross-section or radar propagation loss.

10. The echo simulation system for range ambiguity resolution radar according to claim 6, characterized in that, When multiple false signals need to be simulated simultaneously, the delay and Doppler modulation module generates simulated echo pulse signals corresponding to each false target, and outputs the superimposed signals of the multiple modulated signals.

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