Precise pulse compression methods, systems, equipment, and media for broadband linear frequency modulated echo signals.

Abstract

A method, system, device, and medium for precise pulse compression of broadband linear frequency modulated (LFM) echo signals are disclosed. The method includes preprocessing the radar echo signal to obtain an intermediate frequency (IF) echo sequence signal; calculating a velocity scaling factor based on the target radial velocity estimate; calculating and generating a local reference digitized sequence signal based on the velocity scaling factor, combined with the LFM transmit signal's modulation slope and starting frequency; performing M-point discrete Fourier transforms on both the IF echo signal and the local reference digitized sequence signal; taking the conjugate of the M-point Fourier transform result of the local reference digitized signal and multiplying it by the M-point Fourier transform result of the IF echo signal; and then performing an inverse Fourier transform on the result to obtain the precise pulse compression result of the echo signal. The first N values ​​of the precise pulse compression result are then selected. r The value of each point is used as the final pulse compression result output; the system, equipment and media are used to realize a precise pulse compression method for broadband linear frequency modulated echo signals; thus improving detection accuracy.

Description

Technical Field

[0001] This invention relates to the field of radar signal processing technology, and specifically to a method, system, device, and medium for precise pulse compression of broadband linear frequency modulated echo signals. Background Technology

[0002] With the increasing demand for high-precision detection of hypersonic targets, broadband radar pulse signals combined with pulse compression technology are gaining popularity due to their ability to achieve high-precision detection. Among these technologies, broadband linear frequency modulated pulse signals are widely used due to their ease of generation and processing. However, hypersonic targets have extremely high flight speeds (typically reaching several Mach to tens of Mach), which causes frequency modulation effects in radar echoes, resulting in Doppler frequency shifts and changes in spectral distribution. If the influence of target velocity is not considered and pulse compression is directly applied to the radar echo, the position of the peak point of the compressed echo pulse (corresponding to the radial distance of the target) will be shifted, and the pulse compression waveform (corresponding to the target's shape and attitude characteristics) will also be distorted, leading to detection deviations or anomalies.

[0003] To eliminate detection biases of moving targets, existing technologies typically involve pre-estimating the target's velocity in real time. At the radar receiver, for each pulse repetition period (PRI), a Doppler oscillation signal determined based on the target velocity is generated. This signal is then multiplied by a local reference signal used for pulse compression, resulting in a corrected local reference signal. Using this corrected local reference signal to compress the radar echo can reduce or offset detection biases or anomalies caused by target velocity to some extent. However, due to the extremely high flight speeds of hypersonic targets, the conventional methods described above cannot completely eliminate detection anomalies caused by target velocity.

[0004] The paper "Motion Compensation for Wideband Linear Frequency Modulation Signals of Airborne PD Radar" (Firepower and Command Control, 2015, Vol.40, No.6, pp:1107-1111) proposes a motion compensation method by improving the matched filter function. However, this method mainly focuses on improving the detection resolution of the target azimuth dimension when the inter-pulse signal is coherently accumulated, and does not focus on improving the radial range dimension. Therefore, this method cannot solve the deviation or anomaly problem caused by the target velocity mentioned above.

[0005] Chinese patent application CN115372924A discloses a method for accurate equalization compensation of distortion in broadband pulse compression signals. This method involves performing Fourier Transform (FFT) processing on multiple acquired echo loop data and comparing the results with theoretical FFT values ​​to obtain amplitude and phase compensation coefficients. These coefficients are then used to correct the echo signal, thus achieving a certain degree of correction for echo spectral distortion. However, the implementation of this method is highly dependent on the quality and statistical consistency of the echo data. Differences in target motion parameters corresponding to multiple echo data sets and variations in the link environment reduce the effectiveness of this method in practical applications. Summary of the Invention

[0006] To overcome the shortcomings of the prior art, the present invention aims to provide a precise pulse compression method, system, device, and medium for broadband linear frequency modulated echo signals. By using parameters such as the target radial velocity, the frequency modulation slope of the linear frequency modulated signal, and the starting frequency, a local reference signal adapted to the target echo is calculated and generated. This reference signal is used to perform pulse compression processing on the echo, ultimately obtaining a precise pulse compression processing result and improving the detection accuracy.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0008] A precise pulse compression method for broadband linear frequency modulated echo signals includes the following steps:

[0009] S1, preprocess the radar echo signal to obtain the digitized intermediate frequency echo sequence signal r. d (n);

[0010] S2, calculate the velocity proportionality coefficient η based on the target radial velocity estimate v;

[0011] S3, based on the speed proportionality coefficient η calculated in step S2, and combined with the known frequency modulation slope k and starting frequency f0 of the linear frequency modulated transmission signal, calculate and generate the local reference digitized sequence signal u for precise pulse compression. base (n);

[0012] S4, respectively process the digitally sampled intermediate frequency echo signal r obtained in step S1. d (n) and the local reference digitized sequence signal u generated in step S3 base (n) Perform the Discrete Fourier Transform (FFT) on the M points;

[0013] S5, The local reference digitized sequence signal u from step S4... base The conjugate of the M-point Fourier transform result of (n) is then combined with the intermediate frequency echo signal r from step S4. dMultiply the M-point Fourier transform results of (n), and then perform an inverse Fourier transform (IFFT) on the multiplied result to obtain the accurate pulse compression result r of the echo signal. pc (n), taking the precise pulse compression result r pc The first N of (n) r The values ​​of each point are output as the final pulse pressure result.

[0014] Step S1 specifically includes the following steps:

[0015] At the radar receiver, for each pulse repetition period (PRI), the radar echo signal r(t) is received, and the real-time estimate of the radial velocity v of the target to be detected, as well as the time delay values ​​τ corresponding to the start and end positions of the gate, are obtained. start and τ end ;

[0016] Then, the echo signal r(t) is down-converted to an intermediate frequency signal, and the delay value τ is adjusted according to the start and end of the gate. start and τ end The echo after down-conversion is truncated to obtain the truncated echo signal r'(t), whose expression is:

[0017] r'(t)=G(t)r(t+τ start )exp(-j2πf Δ t)(1-5)

[0018] Among them, f Δ G(t) represents the decreasing frequency in the downconversion process, and G(t) is the envelope window function used for gate truncation, whose expression is:

[0019]

[0020] The echo signal r'(t) is then digitally sampled to obtain the digitized intermediate frequency echo sequence signal r. d (n), whose expression is:

[0021] r d (n)=r'(nT s (1-7)

[0022] Among them, T s The sampling interval is n, and n is the index value of the discrete sequence, which takes the values: 0, 1, 2, ..., N. r -1, where N r For digital intermediate frequency echo r d (n) is the total number of sampling points.

[0023] The expression for calculating the speed proportionality coefficient η in step S2 is:

[0024]

[0025] Where c is the speed of electromagnetic waves.

[0026] The local reference digitized sequence signal u mentioned in step S3 base The expression for (n) is:

[0027]

[0028] Among them, A u (·) represents the envelope function, and the discrete sequence index value n takes the values: 0, 1, 2, ..., N. u -1, where N u For digital reference signal u base (n) is the total number of sampling points.

[0029] Step S4 specifically includes:

[0030] Let r d The M-point Fourier transform result of (n) is F r (ω), u base The M-point Fourier transform result of (n) is F u (ω), where ω is a digital angular frequency variable, its value ranges from 0 to 2π, and the interval between adjacent values ​​is . Then F r (ω), F u (ω) can be expressed as:

[0031]

[0032] Where M satisfies M≥N r +N u -1, FFT(·) represents the Discrete Fourier Transform.

[0033] The precise pulse compression result r in step S5 pc (n) is expressed in the following form:

[0034]

[0035] In this context, the superscript '*' indicates the conjugate operation, and IFFT(·) represents the discrete inverse Fourier transform.

[0036] A system for precise pulse compression of broadband linear frequency modulated echo signals includes:

[0037] The radar echo signal preprocessing module down-converts the received radar echo signal, then truncates it according to the start and end delay values ​​of the gate, and finally performs digital sampling to obtain a digitized intermediate frequency echo sequence r. d (n);

[0038] The local reference digitized signal generation module generates a local reference digitized signal u for precise pulse compression based on the target velocity scaling factor η, the frequency modulation slope k, and the starting frequency f0. base (n);

[0039] The pulse compression module processes the digitized intermediate frequency echo sequence signal r. d (n) and the local reference digitized sequence signal u base (n) Perform discrete Fourier transforms on each, and obtain the transform results F. r (ω) and F u (ω), then for F u (ω) Find the conjugate with F r Multiply by (ω), then perform an inverse Fourier transform on the result to obtain the accurate pulse compression result r. pc (n).

[0040] Precision pulse compression equipment for broadband linear frequency modulated echo signals includes:

[0041] Memory: Used to store the program and digital signal data for implementing the precise pulse compression method for broadband linear frequency modulated echo signals;

[0042] Processor: Used to implement the precise pulse compression method for broadband linear frequency modulated echo signals when executing the program.

[0043] A computer-readable storage medium storing a computer program that, when executed by a processor, implements the steps of the precise pulse compression method for broadband linear frequency modulated echo signals.

[0044] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0045] This invention constructs a local reference digitized signal u base (n) takes into account the fine frequency and phase changes caused by the target velocity, which is more compatible with the echo signal, so that the pulse compression of the echo using the local reference signal constructed in this invention can obtain more accurate pulse compression results.

[0046] The local reference digitized signal u used in this invention base (n) has better matching with radar echo signals, resulting in higher pulse compression peak values ​​and higher pulse compression power, which in turn improves the sensitivity of hypersonic target detection to a certain extent.

[0047] In summary, this invention features precise pulse compression and high sensitivity to hypersonic target detection. Attached Figure Description

[0048] Figure 1 This is a flowchart of an embodiment of the present invention.

[0049] Figure 2 The figures show the simulation results of pulse compression for embodiments of the present invention and existing technologies. Detailed Implementation

[0050] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] The linear frequency modulated radar echo signal involved in this invention is the echo reflected from a linear frequency modulated radar wave emitted by an active radar after it comes into contact with a target, and then converted into an electrical signal after being received by a radar receiver, denoted as r(t). Its mathematical expression can be modeled as follows:

[0052]

[0053] Where N is the number of scattering points of the target or group of targets to be detected, and these N scattering points are assumed to have the same radial velocity v (assuming the positive direction of v is away from the radar receiver). Note that if there are differences in the radial velocities among these N scattering points, their average radial velocity can be taken as the value of v. t is a time variable and t≥0. i θ i τ i Let be the amplitude, phase, and time delay values ​​of the echo component corresponding to the i-th scattering point, respectively, where i = 1, 2, ..., N, exp(·) is the exponential function, j is the imaginary unit, ξ is the scale factor, and u(t) is the radar linear frequency modulated transmission signal.

[0054] The scale factor ξ is expressed as follows:

[0055]

[0056] Where c is the speed of electromagnetic waves, which is equal to the speed of light and can be taken as 3 × 10⁻⁶. 8 m / s.

[0057] The expression for the radar linear frequency modulated transmitted signal u(t) is:

[0058] u(t) = A u (t)exp(j(2πf0t+πkt 2 ))(1-3)

[0059] Where f0 is the starting frequency of the linear frequency modulated signal. Let B be the frequency modulation slope of the linear frequency modulated signal, B be the signal bandwidth, P be the signal pulse width, and A be the frequency modulation slope. u (t) is the amplitude envelope window function, and without loss of generality, we can take A. u (t) is a rectangular window function, and its expression is:

[0060]

[0061] See Figure 1 A precise pulse compression method for broadband linear frequency modulated echo signals includes the following steps:

[0062] S1, preprocess the radar echo signal to obtain the digitized intermediate frequency echo sequence signal r. d (n);

[0063] S2, calculate the velocity proportionality coefficient η based on the target radial velocity estimate v;

[0064] S3, based on the speed proportionality coefficient η calculated in step S2, and combined with the known frequency modulation slope k and starting frequency f0 of the linear frequency modulated transmission signal, calculate and generate the local reference digitized sequence signal u for precise pulse compression. base (n);

[0065] S4, respectively process the digitally sampled intermediate frequency echo signal r obtained in step S1. d (n) and the local reference digitized sequence signal u generated in step S3 base (n) Perform the Discrete Fourier Transform (FFT) on the M points;

[0066] S5, The local reference digitized sequence signal u from step S4... base The conjugate of the M-point Fourier transform result of (n) is then combined with the intermediate frequency echo signal r from step S4. d Multiply the M-point Fourier transform results of (n), and then perform an inverse Fourier transform (IFFT) on the multiplied result to obtain the accurate pulse compression result r of the echo signal. pc (n), taking the precise pulse compression result r pc The first N of (n) r The values ​​of each point are output as the final pulse pressure result.

[0067] Step S1 specifically includes the following steps:

[0068] At the radar receiver, for each pulse repetition period (PRI), the radar echo signal r(t) is received, and the real-time estimate of the radial velocity v of the target to be detected, as well as the time delay values ​​τ corresponding to the start and end positions of the gate, are obtained. start and τend Note the target's radial velocity estimate v and the gate start and end delay values ​​τ. start and τ end All of these can be obtained through known technologies, which are common knowledge in the field of radar signal processing;

[0069] Then, the echo signal r(t) is down-converted to an intermediate frequency signal, and the delay value τ is adjusted according to the start and end of the gate. start and τ end The echo after down-conversion is truncated to obtain the truncated echo signal r'(t), whose expression is:

[0070] r'(t)=G(t)r(t+τ start )exp(-j2πf Δ t)(1-5)

[0071] Among them, f Δ G(t) represents the decreasing frequency in the downconversion process, and G(t) is the envelope window function used for gate truncation, whose expression is:

[0072]

[0073] The echo signal r'(t) is then digitally sampled to obtain the digitized intermediate frequency echo sequence signal r. d (n), whose expression is:

[0074] r d (n)=r'(nT s (1-7)

[0075] Among them, T s The sampling interval is n, and n is the index value of the discrete sequence, which takes the values: 0, 1, 2, ..., N. r -1, where N r For digital intermediate frequency echo r d (n) is the total number of sampling points.

[0076] The expression for calculating the speed proportionality coefficient η in step S2 is:

[0077]

[0078] Where c is the electromagnetic wave velocity, it can be found that the velocity proportionality coefficient η and the scale factor ξ in equation (1-2) satisfy the relationship: ξ=1-η.

[0079] The local reference digitized sequence signal u mentioned in step S3 base The expression for (n) is:

[0080]

[0081] Among them, A u (·) is the envelope function, whose expression satisfies equation (1-4). The discrete sequence index value n takes the values: 0, 1, 2, ..., N. u -1, where N u For digital reference signal u base (n) is the total number of sampling points.

[0082] Step S4 specifically includes:

[0083] Let r d The M-point Fourier transform result of (n) is F r (ω), u base The M-point Fourier transform result of (n) is F u (ω), where ω is a digital angular frequency variable, its value ranges from 0 to 2π, and the interval between adjacent values ​​is . Then F r (ω), F u (ω) can be expressed as:

[0084]

[0085] Where M satisfies M≥N r +N u -1, FFT(·) represents the Discrete Fourier Transform.

[0086] The precise pulse compression result r in step S5 pc (n) is expressed in the following form:

[0087]

[0088] In this context, the superscript '*' indicates the conjugate operation, and IFFT(·) represents the discrete inverse Fourier transform.

[0089] In principle, the local reference digitized signal u used for precise pulse compression processing base The construction of (n) already considers the precise influence of the target velocity on the echo phase. Without loss of generality, analyzing from the perspective of a single scattering point (e.g., the i-th scattering point), the phase value of the echo corresponding to that scattering point is... This can be expressed as:

[0090]

[0091] right By taking the derivative, we can obtain the frequency variation f of the echo component at that scattering point over time. i (t):

[0092]

[0093] In the derivation of the above formula, Δt i =t-τ i And neglecting higher-order small quantities kΔt i η 2 .

[0094] As can be seen from the derivation results in (1-13), due to the influence of the target velocity, the real-time frequency value of the target echo, except for the linear frequency term f0+kΔt, is affected. i In addition, there is an additional frequency component caused by the target velocity: -f0η-2kΔt i η. If this additional frequency component is not processed, it will cause significant deviations or anomalies in the target detection results. Current processing techniques only compensate for a single Doppler frequency component, corresponding to -f0η in the above formula. This means that the influence of the target velocity cannot be completely eliminated from the detection results, and a non-negligible Doppler residual still exists. This Doppler residual is particularly significant for hypersonic targets, typically leading to main lobe divergence and distortion in pulse compression results, reducing detection accuracy, and even causing detection anomalies.

[0095] This invention considers the influence of more refined frequency components caused by the target velocity. That is, all frequency components f0+kΔt in the result of equation (1-13) are considered. i -f0η-2kΔt i Taking η into account, by integrating it and replacing the time variable, the phase of the local reference signal used for pulse compression is obtained.

[0096]

[0097] Its discretized form corresponds to the phase part in equation (1-9).

[0098] This invention takes into account the precise influence of target velocity on echo frequency and phase, resulting in more accurate pulse compression results that can more accurately reflect the target's motion state, shape, and attitude characteristics.

[0099] The system for the precise pulse compression method of broadband linear frequency modulated echo signals adopts the aforementioned precise pulse compression method for broadband linear frequency modulated echo signals, including:

[0100] The radar echo signal preprocessing module down-converts the received radar echo signal, then truncates it according to the start and end delay values ​​of the gate, and finally performs digital sampling to obtain a digitized intermediate frequency echo sequence r. d (n), which is used to implement step S1 of the precise pulse compression method for broadband linear frequency modulated echo signals;

[0101] The local reference digitized signal generation module generates a local reference digitized signal u for precise pulse compression based on the target velocity scaling factor η, the frequency modulation slope k, and the starting frequency f0. base (n), which are steps S2 and S3 used to implement the precise pulse compression method for broadband linear frequency modulated echo signals;

[0102] The pulse compression module processes the digitized intermediate frequency echo sequence signal r. d (n) and the local reference digitized sequence signal u base (n) Perform discrete Fourier transforms on each, and obtain the transform results F. r (ω) and F u (ω), then for F u (ω) Find the conjugate with F r Multiply by (ω), then perform an inverse Fourier transform on the result to obtain the accurate pulse compression result r. pc (n), which are steps S4 and S5 used to implement a precise pulse compression method for broadband linear frequency modulated echo signals.

[0103] Precision pulse compression equipment for broadband linear frequency modulated echo signals includes:

[0104] Memory: Used to store the program and digital signal data for implementing the precise pulse compression method for broadband linear frequency modulated echo signals;

[0105] Processor: Used to implement the precise pulse compression method for broadband linear frequency modulated echo signals when executing the program.

[0106] A computer-readable storage medium storing a program that, when executed by a processor, implements the steps of the precise pulse compression method for broadband linear frequency modulated echo signals.

[0107] This invention addresses the linear frequency modulation signal and pulse compression processing method, which is most commonly used in radar systems or radar signal processing. In addition to radar systems, it may also be used in other systems or fields, such as sonar systems and ultrasonic detection.

[0108] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

[0109] The effects of this invention can be further illustrated by the following simulations:

[0110] 1. Simulation conditions

[0111] Assume the radar transmit signal is a broadband linear frequency modulated (LFM) signal with a bandwidth of 500MHz, a pulse width of 0.5ms, and a carrier frequency of 9GHz (Note: Carrier frequency = starting frequency + bandwidth / 2). For a given radar pulse repetition period, assume the target is 100km away from the radar receiving station and has a radial velocity of Mach 10 when the radar pulse just contacts the target. The input signal-to-noise ratio of the received echo is set to -20dB. For ease of processing, only the case of a single scattering point is simulated. Other parameters have no substantial impact on the simulation results and are not listed here.

[0112] 2. Simulation Content

[0113] Under the above simulation conditions, pulse compression processing of radar echoes was performed using both the method of this invention and the conventional method, and the results are as follows: Figure 2 As shown.

[0114] Depend on Figure 2 As can be seen, regarding the hypersonic target pulse compression results in the simulation example, the existing technology, by only considering compensation for a single Doppler frequency when constructing the local reference signal, fails to achieve a good match between the reference signal and the echo signal, resulting in: 1) main lobe divergence and distortion in the pulse compression result, leading to reduced target detection accuracy; 2) reduced main lobe power in the pulse compression result, leading to reduced target detection sensitivity. In contrast, the technology of this invention considers the fine Doppler frequency changes caused by the target velocity when constructing the local reference signal, resulting in better matching between the constructed reference signal and the echo signal, leading to: 1) a more concentrated main lobe in the pulse compression, improving target detection accuracy; 2) higher main lobe power in the pulse compression result, improving target detection sensitivity.

Claims

1. An accurate pulse compression method for wideband linear frequency modulated echo signals, characterized in that, The method comprises the following steps: S1, pre-process the radar echo signal to obtain a digitized intermediate frequency echo sequence signal r d (n); S2, calculating a velocity scaling factor η according to the target radial velocity estimation value v; S3, according to the speed ratio coefficient η calculated in step S2, in combination with the known frequency modulation slope k and starting frequency f0 of the linear frequency modulation transmitting signal, calculate and generate the local reference digitized sequence signal u for accurate pulse compression base (n); S4, performing a discrete Fourier transform FFT on the M-point digitalized intermediate frequency echo signal r(n) obtained in step S3 d (n) and the local reference digitalized sequence signal u(n) generated in step S3 base (n) to generate a M-point discrete Fourier transformed signal R(k) S5, taking the conjugate of the M-point Fourier transform result of u base (n) and multiplying it with the M-point Fourier transform result of r d (n) in step S4, then performing inverse Fourier transform IFFT on the multiplication result to obtain the accurate pulse compression result r pc (n) of r pc (n) of the first N r points as the final pulse compression result output.

2. The method for accurate pulse compression for wideband linear frequency-modulated echo signals according to claim 1, characterized in that, The step S1 specifically comprises the following steps: At the radar receiving end, for each pulse repetition period PRI, a radar echo signal r(t) is received, and a radial velocity real-time estimation value v of a target to be detected is obtained, and time delay values τ corresponding to the start and end positions of a gate start and τ end ; Then, the echo signal r(t) is down-converted to an intermediate frequency signal, and the down-converted echo signal is intercepted according to the wave gate start and end time delay values τ start and τ end The down-converted echo is intercepted to obtain an intercepted echo signal r'(t), which is expressed as: r'(t) = G(t) r(t + τ start ) exp(-j2πf △ t)(1 - 5) where f △ is the amount of frequency reduction in the down-conversion process, and G(t) is an envelope window function used for the gating, which is expressed as The echo signal r'(t) is then digitally sampled to obtain a digitized intermediate frequency echo sequence signal r d (n), whose expression is: r d (n) = r'(nT s )(1-7) where T s is the sampling interval, n is the index value of the discrete sequence, and n = 0, 1, 2,..., N r - 1, where N r is the total number of sampling points of the digitized intermediate frequency echo r d (n).

3. The method for accurate pulse compression of wideband linear frequency modulated echo signals as claimed in claim 1 wherein, The velocity scaling factor η calculation expression of the step S2 is: Wherein, c is the electromagnetic wave speed.

4. The method for accurate pulse compression of wideband linear frequency modulated echo signals as claimed in claim 1 wherein, The local reference digitized sequence signal u described in step S3 base (n) The calculation expression is: where A u (·) is an envelope function, and the index value n of the discrete sequence takes values: 0, 1, 2,..., N u - 1, where N u is the total number of sampling points of the digitized reference signal u base (n), f △ is the down-conversion frequency amount in the down-conversion processing, T s is the sampling interval.

5. The method for accurate pulse compression of wideband linear frequency modulated echo signals as claimed in claim 1 wherein, The step S4 specifically comprises: Let r d The M-point Fourier transform result of x r (ω), u base The M-point Fourier transform result of x u (ω), where ω is a digital angular frequency variable, and its value range is 0~2π, and the interval of adjacent values is Then F r (ω) and F u (ω) can be expressed as: where M satisfies M≥N r +N u -1, FFT(·) represents a discrete Fourier transform, N u is the total number of sampling points of the digitized reference signal u base (n).

6. The method for accurate pulse compression of wideband linear frequency modulated echo signals as claimed in claim 1 wherein, The precise pulse compression result r in step S5 pc (n) is expressed in the form: Wherein, the upper index '*' represents the conjugate operation, and IFFT(·) represents the discrete inverse Fourier transform.

7. System for accurate pulse compression of a wideband linear frequency modulated echo signal according to any one of claims 1 to 6, characterized in that Comprise: The radar echo signal preprocessing module performs down-conversion processing on the received radar echo signal, then performs interception processing according to the wave gate start and end time delay values, and then performs digital sampling, to obtain a digitized intermediate frequency echo sequence r d (n); The local reference digitized signal generation module generates a local reference digitized signal u for making accurate pulse compression according to target speed proportional coefficient η, frequency modulation slope k and initial frequency f0 base (n); a pulse compression module for digitally processing the intermediate frequency echo sequence signal r d (n) and a local reference digital sequence signal u base (n) are subjected to a discrete Fourier transform, respectively, to obtain transform results F r (ω) and F u (ω), respectively, and the conjugate of F u (ω) is multiplied by F r (ω) to obtain a result, which is subjected to an inverse Fourier transform to obtain an accurate pulse compression result r pc (n).

8. An accurate pulse compression device for wideband linear frequency modulated return signals, characterized by Comprise: Memory: for storing the program and digital signal data of the accurate pulse compression method for wideband linear frequency modulation echo signal according to any one of claims 1-6; Processor: for executing the program to realize the accurate pulse compression method for wideband linear frequency modulation echo signal according to any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a program, and the program is executed by the processor to realize the steps of the accurate pulse compression method for wideband linear frequency modulation echo signal according to any one of claims 1-6.

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