A radar echo real-time simulation method and device

Abstract

The application provides a radar wave real-time simulation method and device. The application first calculates the distance offset and complex scattering coefficient of scattering points in a scene relative to a reference distance; constructs a total modulation template corresponding to a current pulse according to the distance offset and complex scattering coefficient, constructs a sparse frequency domain modulation vector for a modulation component, and performs effective frequency band compression to obtain a compressed sparse frequency domain modulation vector; performs IFFT transformation on the compressed sparse frequency domain modulation vector and performs time domain extraction to obtain a compressed time domain modulation template; when generating a simulation echo, performs interpolation recovery and common phase compensation on the extracted time domain modulation template. The simulation echo digital sequence is converted into an analog signal through digital-to-analog conversion, up-converted in frequency, and adjusted in power, and then output or transmitted, to form a radar simulation echo. The application greatly reduces the calculation amount and storage overhead of a multi-scattering point scene, can realize real-time generation of a wideband complex scene radar echo under a hardware pipeline architecture, and balances the simulation accuracy and hardware resource overhead.

Description

Technical Field

[0001] This invention relates to the fields of radar signal processing and radar target simulation technology, and in particular to a method and apparatus for real-time radar echo simulation. Background Technology

[0002] Radar target simulators are widely used in the research, development, testing and performance evaluation of radar systems. Their main function is to modulate and process radar transmitted signals to generate simulated echoes containing information such as target distance, velocity and scattering characteristics, so as to achieve controllable simulation of real or complex scenarios.

[0003] Existing echo simulation methods mainly include the Digital Radio Frequency Memory (DRFM) method and the convolution method. The DRFM method achieves echo simulation through delay, amplitude and phase modulation, and frequency shift. It has a simple structure and is easy to implement, but it requires significant hardware resources in multi-target or multi-scattering point scenarios, and its distance simulation accuracy is limited, making it difficult to simultaneously meet the requirements of large scenes and high resolution. The convolution method generates the echo by constructing an impulse response function and convolving it with the transmitted signal. It has a more complete physical model, but its computational complexity is high and its real-time performance is limited in broadband signals and complex scenarios.

[0004] In recent years, product modulation methods have gradually attracted attention. This method utilizes the characteristics of linear frequency modulated signals, equating range delay to frequency modulation. It generates echoes by multiplying a modulation function with a reference signal, offering advantages such as simple computational structure, good real-time performance, and ease of hardware implementation. However, existing methods still have shortcomings in complex scenarios and real-time simulation conditions: different phases (range, Doppler, etc.) lack a unified expression, and parameter updates are complex; moreover, calculating the contribution of each scattering point point by point results in a large computational burden for template generation in multi-scattering-point scenarios, making it difficult to meet real-time requirements. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method and apparatus for real-time radar echo simulation, thereby resolving the problems existing in the prior art.

[0006] In a first aspect, the present invention provides a method for real-time simulation of radar echoes, comprising:

[0007] The radar transmits radio frequency signals and performs analog-to-digital conversion to obtain a reference signal sampling sequence within a single pulse repetition interval;

[0008] Based on the spatial location of the radar platform, the spatial location of the corresponding scattering point, and the current slow time, calculate the distance offset and complex scattering coefficient of the scattering point relative to the reference distance in the scene;

[0009] The total modulation template corresponding to the current pulse is constructed based on the range offset and complex scattering coefficients. A sparse frequency domain modulation vector is constructed based on the modulation components of the total modulation template and its effective frequency band is compressed to obtain a compressed sparse frequency domain modulation vector. An IFFT transform is performed on the compressed sparse frequency domain modulation vector and time domain decimation is performed to obtain a compressed time domain modulation template.

[0010] When generating the analog echo, the compressed time-domain modulation template is interpolated and recovered and common phase compensated to obtain a standard modulation template of length N. The reference signal sampling sequence is multiplied point by point with the standard modulation template to obtain the analog echo digital sequence.

[0011] The simulated echo digital sequence is converted from digital to analog, up-converted, and power adjusted before being output or transmitted to form a radar simulated echo with preset target distance, velocity, scattering intensity, and phase history characteristics.

[0012] Secondly, the present invention provides a real-time radar echo simulation device, comprising:

[0013] The data acquisition module is used to acquire the radar's transmitted radio frequency signals and perform analog-to-digital conversion to obtain the reference signal sampling sequence within a single pulse repetition interval;

[0014] The range offset calculation module is used to calculate the range offset and complex scattering coefficient of the scattering point relative to the reference distance in the scene based on the spatial position of the radar platform, the spatial position of the corresponding scattering point, and the current slow time.

[0015] The modulation template generation module is used to construct the total modulation template corresponding to the current pulse based on the distance offset and complex scattering coefficients, construct a sparse frequency domain modulation vector based on the modulation components of the total modulation template, and compress the effective frequency band of the vector to obtain the compressed sparse frequency domain modulation vector. The compressed sparse frequency domain modulation vector is then subjected to IFFT transformation and time domain decimation to obtain the compressed time domain modulation template.

[0016] The analog echo generation module is used to perform interpolation recovery and common phase compensation on the compressed time-domain modulation template to obtain a standard modulation template of length N when generating the analog echo, and multiply the reference signal sampling sequence with the standard modulation template point by point to obtain the analog echo digital sequence.

[0017] The output module is used to output or transmit the analog echo digital sequence after digital-to-analog conversion, up-conversion and power adjustment, so as to form a radar analog echo with preset target distance, velocity, scattering intensity and phase history characteristics.

[0018] Thirdly, the present invention provides an electronic device, comprising:

[0019] At least one processor;

[0020] and a memory communicatively connected to the at least one processor;

[0021] The memory stores a computer program that can be executed by at least one processor, and when the computer program is executed by the at least one processor, it implements the real-time radar echo simulation method.

[0022] Fourthly, the present invention provides a computer storage medium storing a computer program, which, when executed by a processor, implements the real-time radar echo simulation method.

[0023] The beneficial effects of this invention are as follows:

[0024] 1. This invention represents the slow-time phase term and the fast-time frequency shift term as a complex exponential modulation template. The template can be refreshed simply by updating the scattering point distance offset and the complex scattering coefficient, thus reducing the complexity of parameter updates in dynamic scenarios.

[0025] 2. This invention transforms the point-by-point accumulation of multiple scattering points in the time domain into a sparse mapping in the frequency domain, coherent accumulation of complex weights, and IFFT operation, thereby reducing repeated calculations of complex exponents and improving real-time performance in multi-scattering point scenarios.

[0026] 3. This invention constructs a refined frequency domain grid by upsampling coefficient L, thereby reducing the equivalent frequency shift mapping error, and thus reducing the distance offset error and phase error.

[0027] 4. This invention performs effective frequency band compression based on the scene distance offset range and adopts common phase unified compensation to reduce the amount of frequency domain data and cache resource occupation. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating the method of an embodiment of the present invention;

[0029] Figure 2 This is a schematic diagram of the modulation template generation process in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of compressed storage of effective bandwidth according to an embodiment of the present invention;

[0031] Figure 4 This is a geometrical schematic diagram of real-time radar echo simulation according to an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the real-time simulated radar echo imaging results according to an embodiment of the present invention;

[0033] Figure 6 This is a structural framework diagram of the device according to an embodiment of the present invention.

[0034] In the diagram, 10 is the data acquisition module; 20 is the distance offset calculation module; 30 is the modulation template generation module; 40 is the simulated echo generation module; and 50 is the output module. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0036] like Figure 1 As shown, this embodiment provides a real-time radar echo simulation method, including:

[0037] S1) Acquire the radar's transmitted radio frequency signal and perform analog-to-digital conversion to obtain the reference signal sampling sequence within a single pulse repetition interval;

[0038] S2) Based on the spatial location of the radar platform and the corresponding spatial location of the scattering point, as well as the current slow time, calculate the distance offset and complex scattering coefficient of the scattering point relative to the reference distance in the scene;

[0039] S3) Construct the total modulation template corresponding to the current pulse based on the distance offset and complex scattering coefficients. Construct a sparse frequency domain modulation vector based on the modulation components of the total modulation template and compress its effective frequency band to obtain a compressed sparse frequency domain modulation vector. Perform IFFT transformation on the compressed sparse frequency domain modulation vector and perform time domain decimation to obtain a compressed time domain modulation template.

[0040] S4) When generating the analog echo, the compressed time-domain modulation template is interpolated and recovered and common phase compensated to obtain a standard modulation template of length N. The reference signal sampling sequence is multiplied point by point with the standard modulation template to obtain the analog echo digital sequence.

[0041] S5) The simulated echo digital sequence is converted from digital to analog, up-converted and power adjusted, and then output or transmitted to form a radar simulated echo with preset target distance, velocity, scattering intensity and phase history characteristics.

[0042] In some embodiments, the reference signal sampling sequence is a direct sampling sequence of the radar transmitted signal, or a reference echo sequence obtained after equivalent phase correction of the radar transmitted signal based on a reference distance.

[0043] In this embodiment, step S2) involves calculating the range offset and complex scattering coefficient of the scattering point relative to the reference distance in the scene, based on the spatial location of the radar platform, the spatial location of the corresponding scattering point, and the current slow time; including:

[0044] S21) Calculate the instantaneous spatial position of the reference reference origin relative to the radar platform to obtain the reference reference range. ,Right now:

[0045] ;

[0046] In the formula, The origin is the reference point; This refers to the instantaneous spatial position of the radar platform; Slow time; It is an L2 norm;

[0047] S22) Calculate the instantaneous slant range of the scattering point relative to the radar based on the instantaneous spatial position of the radar platform and the spatial position of the corresponding scattering point. ,Right now:

[0048] ;

[0049] In the formula, Let n be the spatial location of the scattering point.

[0050] S23), based on the relative instantaneous slant range of the scattering point to the radar Distance from the reference point The distance offset of the scattering point relative to the reference distance is calculated. ,Right now:

[0051] ;

[0052] In the formula, For scattering points Distance offset relative to the reference distance;

[0053] S24) The complex scattering coefficient is calculated based on the amplitude term that varies with slow time and the initial scattering phase. ,Right now:

[0054] ;

[0055] In the formula, For amplitude terms; This is the initial phase of scattering; It is an imaginary number;

[0056] In this embodiment, the amplitude term is adjusted according to different simulation scenarios. They are represented as follows:

[0057] For a stationary ideal point target, the amplitude term , For fixed scattering amplitude;

[0058] For common airborne or shipboard scenarios, the aforementioned amplitude term ;in, For the first The normalized RCS fluctuation random coefficients of each scattering point.

[0059] In this embodiment, for ideal fixed scattering, ; The initial phase is a constant.

[0060] For targets that are slightly moving or rotating ; The target micro-motion angular frequency.

[0061] In this embodiment, in step S3), a total modulation template corresponding to the current pulse is constructed based on the range offset and complex scattering coefficients. A sparse frequency domain modulation vector is constructed based on the modulation components of the total modulation template, and its effective bandwidth is compressed to obtain a compressed sparse frequency domain modulation vector. An IFFT transform is performed on the compressed sparse frequency domain modulation vector, and time-domain decimation is performed to obtain a compressed time-domain modulation template. Figure 2 As shown, it includes:

[0062] S31), based on radar at the reference reference range The modulation component corresponding to a single scattering point is calculated from the reference echo and the expected echo of the scattering point. The modulation components of all scattering points in the scene are then superimposed to obtain the current slow time. The overall modulation template below;

[0063] In this embodiment, a reference distance is set. The radar at the reference range The corresponding reference echo is :

[0064] ;

[0065] In the formula, To save time, For sampling points, Indicates the sampling rate; Represents a rectangular window function; For round-trip time; The pulse duration; Wavelength; Frequency modulation for linear frequency modulation signals; Used as a reference distance;

[0066] In this embodiment, if there exists a scene with a distance offset of... The scattering point, then the expected echo of the scattering point. for:

[0067] ;

[0068] In the formula, For scattering points Relative radar instantaneous slant range; is the complex scattering coefficient.

[0069] In this embodiment, based on the radar at the reference reference distance Calculate the modulation component corresponding to a single scattering point based on the reference echo and the expected echo of the scattering point. ,Right now:

[0070] ;

[0071] in, For the first The equivalent frequency shift of each scattering point caused by the distance offset; It is the speed of light.

[0072] In this embodiment, the current slow time is obtained by superimposing the modulation components of all scattering points in the scene. The overall modulation template below, namely:

[0073] ;

[0074] In the formula, The slow-time phase term is used to characterize the first... The round-trip propagation phase difference introduced by each scattering point relative to the reference distance; This is a fast time-shift term used to characterize the equivalent frequency shift effect of the range offset in the fast time dimension within the pulse; This represents the number of scattering points within the scene.

[0075] S32) Represent the modulation component corresponding to each scattering point as an equivalent complex weight and an equivalent frequency shift, and then convert the equivalent frequency shift... A refined frequency domain grid, constructed from upsampling coefficients, is mapped to a discrete frequency domain grid. Equivalent complex weights mapped to the same frequency domain grid point are coherently accumulated to construct a sparse frequency domain modulation vector; including:

[0076] In this embodiment, the total modulation template is rewritten as the equivalent complex weights and equivalent frequencies of each scattering point, that is:

[0077] ;

[0078] ;

[0079] In the formula, For the first The equivalent complex weights corresponding to each scattering point.

[0080] In this embodiment, by using the first The equivalent frequency shift corresponding to each scattering point Mapping to a discrete frequency grid, we obtain the first... Frequency grid points corresponding to each scattering point ,Right now:

[0081] ;

[0082] In the formula, This represents the rounding function; Indicates frequency interval; is the length of the frequency domain modulation vector.

[0083] The first The equivalent complex weights of the scattering points are accumulated and applied to the corresponding frequency grid points to obtain the _th ... Modulation vector of each scattering point ,Right now:

[0084] ;

[0085] When multiple scattering points are mapped to the same frequency grid point, their equivalent complex weights are coherently accumulated to maintain the amplitude and phase superposition relationship between the multiple scattering points, thus obtaining a sparse frequency domain modulation vector. .

[0086] In this embodiment, an upsampling factor is set. and construct a length of The refined frequency domain grid then the first The scattering points are represented on the refined frequency grid as follows:

[0087] ;

[0088] In the formula, This represents the frequency domain grid point of the nth scattering point under a refined frequency domain grid. Modulo operation represents refining the total number of points by rounding down the index value. Take the remainder; To refine the frequency spacing.

[0089] S33) Based on the distance offset interval of scattering points in the scene, select the minimum distance offset as a common compensation term to effectively compress the sparse frequency domain modulation vector;

[0090] like Figure 3 As shown, in this embodiment, the maximum value based on the scene distance offset is... and minimum value Calculate scene distance span ,Right now:

[0091] ;

[0092] And based on scene distance span Determine the effective number of frequency domain sampling points for compression, i.e.:

[0093] ;

[0094] In the formula, This represents the number of effective frequency domain sampling points.

[0095] In this embodiment, the minimum scene distance offset is selected as the common compensation term. Only the number of sampling points in the effective frequency domain Construct a compressed sparse frequency domain modulation vector within the finite effective frequency band;

[0096] S34), the compressed sparse frequency domain modulation vector Perform an IFFT transform and then decimate in the time domain to obtain a compressed time-domain modulation template. ;Right now:

[0097] .

[0098] In this embodiment, in step S4), when generating the analog echo, the compressed time-domain modulation template is interpolated and recovered and common phase compensated to obtain a standard modulation template of length N. The reference signal sampling sequence is multiplied point by point with the standard modulation template to obtain the analog echo digital sequence.

[0099] A linear interpolation algorithm is used to expand the short-time template into an intermediate template with a sampling length of N. Finally, the intermediate template is multiplied point by point by the common phase. This yields a standard modulation template of length N.

[0100] By multiplying the reference signal sampling sequence point by point with the standard modulation template, the analog echo digital sequence is obtained, i.e.:

[0101] ;

[0102] In the formula, The reference signal sampling sequence; Indicates the standard modulation template; This is a digital sequence of simulated echoes.

[0103] In this embodiment, step S5) involves outputting or transmitting the simulated echo digital sequence after digital-to-analog conversion, up-conversion, and power adjustment to form a radar simulated echo with preset target range, velocity, scattering intensity, and phase history characteristics, including:

[0104] The analog echo digital sequence The discrete digital quantity is converted into an analog baseband I or Q voltage signal by a digital-to-analog converter;

[0105] The baseband I or Q voltage signal is mixed with the local oscillator carrier and shifted to the radar's operating radio frequency carrier frequency to obtain a radio frequency analog signal;

[0106] The signal power of the radio frequency analog signal is adjusted by programmable attenuation to match the input power level of the radar antenna under test.

[0107] The conditioned radio frequency analog signal is fed into the input terminal of the radar receiver under test through the radio frequency cable, and the output radio frequency echo signal is generated.

[0108] like Figure 4 The diagram shows the spatial geometry of the radar and the target scattering point. This embodiment uses a reference distance. As a unified reference benchmark for the entire field, the relative distance offset of all scattering points is calculated based on this benchmark.

[0109] like Figure 5 As shown, the simulated echo generated based on this embodiment can be used for imaging processing, and the imaging results can reflect the distance, scattering intensity, and phase history characteristics of multi-scattering point targets.

[0110] like Figure 6 As shown, this embodiment also provides a real-time radar echo simulation device, including:

[0111] Data acquisition module 10 is used to acquire radar transmitted radio frequency signals and perform analog-to-digital conversion to obtain a reference signal sampling sequence within a single pulse repetition interval;

[0112] The range offset calculation module 20 is used to calculate the range offset and complex scattering coefficient of the scattering point relative to the reference distance in the scene based on the spatial position of the radar platform, the spatial position of the corresponding scattering point, and the current slow time.

[0113] The modulation template generation module 30 is used to construct the total modulation template corresponding to the current pulse based on the distance offset and complex scattering coefficient, construct a sparse frequency domain modulation vector based on the modulation components of the total modulation template and compress the effective frequency band of the vector to obtain the compressed sparse frequency domain modulation vector, perform IFFT transformation on the compressed sparse frequency domain modulation vector and perform time domain decimation to obtain the compressed time domain modulation template.

[0114] The analog echo generation module 40 is used to perform interpolation recovery and common phase compensation on the compressed time-domain modulation template when generating the analog echo to obtain a standard modulation template of length N, and multiply the reference signal sampling sequence with the standard modulation template point by point to obtain the analog echo digital sequence.

[0115] The output module 50 is used to output or transmit the analog echo digital sequence after digital-to-analog conversion, up-conversion and power adjustment, so as to form a radar analog echo with preset target distance, speed, scattering intensity and phase history characteristics.

[0116] In this embodiment, the reference signal sampling sequence acquired by the data acquisition module 10 is either a direct sampling sequence of the radar transmitted signal or a reference echo sequence obtained after equivalent phase correction of the radar transmitted signal based on the reference distance.

[0117] In this embodiment, the range offset calculation module 20 calculates the range offset and complex scattering coefficient of the scattering point relative to the reference distance in the scene based on the spatial position of the radar platform, the spatial position of the corresponding scattering point, and the current slow time; including:

[0118] The reference range is obtained by calculating the instantaneous spatial position of the reference origin relative to the radar platform. ,Right now:

[0119] ;

[0120] In the formula, The origin is the reference point; This refers to the instantaneous spatial position of the radar platform; Slow time; It is an L2 norm.

[0121] The instantaneous slant range of the scattering point relative to the radar is calculated based on the instantaneous spatial position of the radar platform and the spatial position of the corresponding scattering point. ,Right now:

[0122] ;

[0123] In the formula, Let n be the spatial location of the scattering point.

[0124] Based on the relative instantaneous slant range of the scattering point to the radar Distance from the reference point The distance offset of the scattering point relative to the reference distance is calculated. ,Right now:

[0125] ;

[0126] In the formula, For scattering points Distance offset relative to the reference distance.

[0127] The complex scattering coefficients are calculated based on the amplitude term that varies with slow time and the initial scattering phase. ,Right now:

[0128] ;

[0129] In the formula, For amplitude terms; This is the initial phase of scattering; It is an imaginary number.

[0130] In this embodiment, the amplitude term is adjusted according to different simulation scenarios. They are represented as follows:

[0131] For a stationary ideal point target, the amplitude term , For fixed scattering amplitude;

[0132] For common airborne or shipboard scenarios, the aforementioned amplitude term ;in, For the first The normalized RCS fluctuation random coefficients of each scattering point.

[0133] In this embodiment, for ideal fixed scattering, ; The initial phase is a constant.

[0134] For targets that are slightly moving or rotating ; The target micro-motion angular frequency.

[0135] In this embodiment, the modulation template generation module 30 constructs the total modulation template corresponding to the current pulse based on the range offset and complex scattering coefficients. Based on the modulation components of the total modulation template, a sparse frequency domain modulation vector is constructed and its effective bandwidth is compressed to obtain a compressed sparse frequency domain modulation vector. An IFFT transform is performed on the compressed sparse frequency domain modulation vector, and time-domain decimation is performed to obtain a compressed time-domain modulation template. Figure 2 As shown, it includes:

[0136] Based on radar at the reference range The modulation component corresponding to a single scattering point is calculated from the reference echo and the expected echo of the scattering point. The modulation components of all scattering points in the scene are then superimposed to obtain the current slow time. The overall modulation template below;

[0137] In this embodiment, a reference distance is set. The radar at the reference range The corresponding reference echo is :

[0138] ;

[0139] In the formula, To save time, For sampling points, Indicates the sampling rate; Represents a rectangular window function; For round-trip time; The pulse duration; Wavelength; Frequency modulation for linear frequency modulation signals; Used as a reference distance;

[0140] In this embodiment, if there exists a scene with a distance offset of... The scattering point, then the expected echo of the scattering point. for:

[0141] ;

[0142] In the formula, For scattering points Relative radar instantaneous slant range; is the complex scattering coefficient.

[0143] In this embodiment, based on the radar at the reference reference distance Calculate the modulation component corresponding to a single scattering point based on the reference echo and the expected echo of the scattering point. ,Right now:

[0144] ;

[0145] in, For the first The equivalent frequency shift of each scattering point caused by the distance offset; It is the speed of light.

[0146] In this embodiment, the current slow time is obtained by superimposing the modulation components of all scattering points in the scene. The overall modulation template below, namely:

[0147] ;

[0148] In the formula, The slow-time phase term is used to characterize the first... The round-trip propagation phase difference introduced by each scattering point relative to the reference distance; This is a fast time-shift term used to characterize the equivalent frequency shift effect of the range offset in the fast time dimension within the pulse; This represents the number of scattering points within the scene.

[0149] The modulation component corresponding to each scattering point is represented as an equivalent complex weight and an equivalent frequency shift, and the equivalent frequency shift is... A refined frequency domain grid, constructed from upsampling coefficients, is mapped to a discrete frequency domain grid. Equivalent complex weights mapped to the same frequency domain grid point are coherently accumulated to construct a sparse frequency domain modulation vector; including:

[0150] In this embodiment, the total modulation template is rewritten as the equivalent complex weights and equivalent frequencies of each scattering point, that is:

[0151] ;

[0152] ;

[0153] In the formula, For the first The equivalent complex weights corresponding to each scattering point.

[0154] In this embodiment, by using the first The equivalent frequency shift corresponding to each scattering point Mapping to a discrete frequency grid, we obtain the first... Frequency grid points corresponding to each scattering point ,Right now:

[0155] ;

[0156] In the formula, This represents the rounding function; Indicates frequency interval; is the length of the frequency domain modulation vector.

[0157] The first The equivalent complex weights of the scattering points are accumulated and applied to the corresponding frequency grid points to obtain the _th ... Modulation vector of each scattering point ,Right now:

[0158] ;

[0159] When multiple scattering points are mapped to the same frequency grid point, their equivalent complex weights are coherently accumulated to maintain the amplitude and phase superposition relationship between the multiple scattering points, thus obtaining a sparse frequency domain modulation vector. .

[0160] In this embodiment, an upsampling factor is set. and construct a length of The refined frequency domain grid then the first The scattering points are represented on the refined frequency grid as follows:

[0161] ;

[0162] In the formula, This represents the frequency domain grid point of the nth scattering point under a refined frequency domain grid. Modulo operation represents refining the total number of points by rounding down the index value. Take the remainder; To refine the frequency spacing.

[0163] Based on the distance offset range of scattering points in the scene, the minimum distance offset is selected as a common compensation term to effectively compress the frequency band of the sparse frequency domain modulation vector.

[0164] like Figure 3 As shown, in this embodiment, the maximum value based on the scene distance offset is... and minimum value Calculate scene distance span ,Right now:

[0165] ;

[0166] And based on scene distance span Determine the effective number of frequency domain sampling points for compression, i.e.:

[0167] ;

[0168] In the formula, This represents the number of effective frequency domain sampling points.

[0169] In this embodiment, the minimum scene distance offset is selected as the common compensation term. Only the number of sampling points in the effective frequency domain Construct a compressed sparse frequency domain modulation vector within the finite effective frequency band;

[0170] The compressed sparse frequency domain modulation vector Perform an IFFT transform and then decimate in the time domain to obtain a compressed time-domain modulation template. ;Right now:

[0171] .

[0172] In this embodiment, the analog echo generation module 40 multiplies the reference signal sampling sequence with the standard modulation template point by point to obtain the analog echo digital sequence; that is:

[0173] ;

[0174] In the formula, The reference signal sampling sequence; Indicates the standard modulation template; This is a digital sequence of simulated echoes.

[0175] In this embodiment, the output module 50 outputs or transmits the analog echo digital sequence after digital-to-analog conversion, up-conversion, and power adjustment, forming a radar analog echo with preset target range, velocity, scattering intensity, and phase history characteristics, including:

[0176] The analog echo digital sequence The discrete digital quantity is converted into an analog baseband I or Q voltage signal by a digital-to-analog converter;

[0177] The baseband I or Q voltage signal is mixed with the local oscillator carrier and shifted to the radar's operating radio frequency carrier frequency to obtain a radio frequency analog signal;

[0178] The signal power of the radio frequency analog signal is adjusted by programmable attenuation to match the input power level of the radar antenna under test.

[0179] The conditioned radio frequency analog signal is fed into the input terminal of the radar receiver under test through the radio frequency cable, and the output radio frequency echo signal is generated.

[0180] Embodiments of this application also provide an electronic device, including at least one processor and a memory communicatively connected to the at least one processor, the memory storing a computer program executable by the at least one processor, the computer program implementing the above-described real-time radar echo simulation method when executed.

[0181] Embodiments of this application also provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described real-time radar echo simulation method.

[0182] The embodiments and descriptions above are merely the principles and preferred embodiments of the present invention. Various changes and modifications may be made without departing from the spirit and scope of the present invention, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for real-time simulation of radar echoes, characterized in that, include: The radar transmits radio frequency signals and performs analog-to-digital conversion to obtain a reference signal sampling sequence within a single pulse repetition interval; Based on the spatial location of the radar platform, the spatial location of the corresponding scattering point, and the current slow time, calculate the distance offset and complex scattering coefficient of the scattering point relative to the reference distance in the scene; The total modulation template corresponding to the current pulse is constructed based on the range offset and complex scattering coefficients. A sparse frequency domain modulation vector is constructed based on the modulation components of the total modulation template and its effective frequency band is compressed to obtain a compressed sparse frequency domain modulation vector. An IFFT transform is performed on the compressed sparse frequency domain modulation vector and time domain decimation is performed to obtain a compressed time domain modulation template. When generating the analog echo, the compressed time-domain modulation template is interpolated and recovered and common phase compensated to obtain a standard modulation template of length N. The reference signal sampling sequence is multiplied point by point with the standard modulation template to obtain the analog echo digital sequence. The simulated echo digital sequence is converted from digital to analog, up-converted, and power adjusted before being output or transmitted to form a radar simulated echo with preset target distance, velocity, scattering intensity, and phase history characteristics.

2. The real-time radar echo simulation method according to claim 1, characterized in that: Based on the radar platform motion, target motion parameters, and the current slow time, calculate the range offset of the scattering point relative to the reference distance in the scene; including: The reference distance is obtained by calculating the instantaneous spatial position of the reference origin relative to the radar platform; The instantaneous slant range of the scattering point relative to the radar is calculated based on the instantaneous spatial position of the radar platform and the spatial position of the corresponding scattering point. The distance offset of the scattering point relative to the reference reference distance is calculated based on the instantaneous slant range of the radar relative to the scattering point and the reference reference distance.

3. The real-time radar echo simulation method according to claim 2, characterized in that: The complex scattering coefficient matrix is ​​calculated based on the amplitude and phase terms that vary with slow time.

4. The method for real-time simulation of radar echoes according to claim 1, characterized in that: The total modulation template corresponding to the current pulse is constructed based on the range offset and complex scattering coefficients. A sparse frequency domain modulation vector is constructed based on the modulation components of the total modulation template, and its effective bandwidth is compressed to obtain a compressed sparse frequency domain modulation vector. An IFFT transform is performed on the compressed sparse frequency domain modulation vector, and time-domain decimation is performed to obtain a compressed time-domain modulation template, including: Based on the reference echo and the expected echo of the scattering point at the reference reference distance of the radar, the modulation component corresponding to a single scattering point is calculated, and the modulation components of all scattering points in the scene are superimposed to obtain the total modulation template under the current slow time. The modulation components corresponding to each scattering point are represented as equivalent complex weights and equivalent frequency shifts. The equivalent frequency shifts are mapped to a refined frequency domain grid constructed by upsampling coefficients in the discrete frequency domain grid. The equivalent complex weights mapped to the same frequency domain grid points are coherently accumulated to construct a sparse frequency domain modulation vector. Based on the distance offset range of scattering points in the scene, the minimum distance offset is selected as the common compensation term, and the sparse frequency domain modulation vector is effectively compressed to obtain the compressed sparse frequency domain modulation vector. An IFFT transform is performed on the compressed sparse frequency domain modulation vector, and time-domain decimation is performed to obtain a compressed time-domain modulation template.

5. The real-time radar echo simulation method according to claim 4, characterized in that: Based on the reference echo and the expected echo of the scattering point at the reference reference distance, the modulation component corresponding to a single scattering point is calculated. The modulation components of all scattering points in the scene are superimposed to obtain the total modulation template at the current slow time, including: Set reference distance The radar at the reference range The corresponding reference echo is : ； In the formula, To save time, For sampling point index, Indicates the sampling rate; Represents a rectangular window function; For round-trip time; The pulse duration; Wavelength; Frequency modulation for linear frequency modulation signals; Used as a reference distance; If there exists a distance offset relative to the scene. The scattering point, then the expected echo of the scattering point. for: ； In the formula, For scattering points Relative radar instantaneous slant range; The complex scattering coefficients; Based on the radar at the reference range Calculate the modulation component corresponding to a single scattering point based on the reference echo and the expected echo of the scattering point. ,Right now: ； in, For the first The equivalent frequency shift of each scattering point caused by the distance offset; The speed of light; The current slow time is obtained by superimposing the modulation components of all scattering points in the scene. The overall modulation template below ,Right now: ； In the formula, The slow-time phase term is used to characterize the first... The round-trip propagation phase difference introduced by each scattering point relative to the reference distance; This is a fast time-shift term used to characterize the equivalent frequency shift effect of the range offset in the fast time dimension within the pulse; This represents the number of scattering points within the scene.

6. The real-time radar echo simulation method according to claim 5, characterized in that: The modulation components corresponding to each scattering point are represented as equivalent complex weights and equivalent frequency shifts. The equivalent frequency shifts are mapped to a refined frequency domain grid constructed from upsampling coefficients in the discrete frequency domain grid. The equivalent complex weights mapped to the same frequency domain grid point are coherently accumulated to construct a sparse frequency domain modulation vector, including: The overall modulation template is rewritten as the equivalent complex weights and equivalent frequencies of each scattering point, i.e.: ； ； In the formula, For the first The equivalent complex weights corresponding to each scattering point; By the first The equivalent frequency shift corresponding to each scattering point Mapping to a discrete frequency grid, we obtain the first... Frequency grid points corresponding to each scattering point ; The first The equivalent complex weights of the scattering points are accumulated and applied to the corresponding frequency grid points to obtain the _th ... Modulation vector of each scattering point ,Right now: ； When multiple scattering points are mapped to the same frequency grid point, their equivalent complex weights are coherently accumulated to maintain the amplitude and phase superposition relationship between the multiple scattering points, thus obtaining a sparse frequency domain modulation vector. .

7. The real-time radar echo simulation method according to claim 6, characterized in that: Based on the distance offset interval of scattering points in the scene, the minimum distance offset is selected as a common compensation term, and the sparse frequency domain modulation vector is effectively compressed to obtain the compressed sparse frequency domain modulation vector, including: Maximum value based on scene distance offset and minimum value Calculate scene distance span ,Right now: ； ； In the formula, This represents the number of effective frequency domain sampling points. The minimum scene distance offset is selected as the common compensation item. Only the number of sampling points in the effective frequency domain A compressed sparse frequency domain modulation vector is constructed within the finite effective frequency band.

8. A real-time radar echo simulation device, characterized in that, include: The data acquisition module is used to acquire the radar's transmitted radio frequency signals and perform analog-to-digital conversion to obtain the reference signal sampling sequence within a single pulse repetition interval; The range offset calculation module is used to calculate the range offset and complex scattering coefficient of the scattering point relative to the reference distance in the scene based on the spatial position of the radar platform, the spatial position of the corresponding scattering point, and the current slow time. The modulation template generation module is used to construct the total modulation template corresponding to the current pulse based on the distance offset and complex scattering coefficients, construct a sparse frequency domain modulation vector based on the modulation components of the total modulation template, and compress the effective frequency band of the vector to obtain the compressed sparse frequency domain modulation vector. The compressed sparse frequency domain modulation vector is then subjected to IFFT transformation and time domain decimation to obtain the compressed time domain modulation template. The analog echo generation module is used to perform interpolation recovery and common phase compensation on the compressed time-domain modulation template to obtain a standard modulation template of length N when generating the analog echo, and multiply the reference signal sampling sequence with the standard modulation template point by point to obtain the analog echo digital sequence. The output module is used to output or transmit the analog echo digital sequence after digital-to-analog conversion, up-conversion and power adjustment, so as to form a radar analog echo with preset target distance, velocity, scattering intensity and phase history characteristics.

9. An electronic device, comprising: At least one processor; and a memory communicatively connected to the at least one processor; The memory stores a computer program that can be executed by at least one processor, characterized in that the computer program, when executed by the at least one processor, implements the real-time radar echo simulation method as described in any one of claims 1-7.

10. A computer storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, it implements the real-time radar echo simulation method as described in any one of claims 1-7.

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