A method, system, and apparatus for processing ultra-high-speed target echo signals

Abstract

This invention discloses a method, system, and apparatus for processing ultra-high-speed target echo signals, belonging to the field of signal processing technology. The method includes: dividing the possible radial motion velocity range of a high-speed target into multiple velocity levels; constructing a corresponding reference signal for each velocity level; multiplying the range-dimensional spectrum of the target echo from the intra-pulse motion model with the conjugate of the reference signal to obtain a frequency-domain pulse compression result; matching the reference signal with the echo signal; constructing a migrating phase compensation function; performing slow-time phase compensation on the migrating phase-compensated echo signal; performing range-dimensional IFFT processing on the echo signal; and performing MTD processing on the output signal of the range-dimensional IFFT. This invention effectively solves the range migration problem of high-speed target echoes and the mismatch filtering caused by echo scale transformation, thereby more accurately estimating the target velocity and range information.

Description

Technical Field

[0001] This invention belongs to the field of signal processing technology, specifically relating to a method, system, and apparatus for processing ultra-high-speed target echo signals. Background Technology

[0002] Robust and effective radar moving target detection has always been a challenge in the field of radar signal processing. Therefore, researching signal processing methods for rapid target detection in radar is of great significance. In recent years, with the development of target equipment, high-speed targets have emerged in large numbers. These targets are characterized by good stealth capabilities and high speed. Therefore, when radar illuminates such targets, it causes phase changes in the echo. At the same time, the target will cross multiple range cells, producing a range migration effect, which disperses the target energy, reduces the coherent accumulation gain and MTD performance, and makes it impossible for the radar to accurately estimate the target's range, speed, and other information, thus increasing the difficulty of radar target detection.

[0003] Current moving target detection methods mainly employ two types of conventional algorithms. One type is non-coherent algorithms, including TBD and Hough transform. These algorithms accumulate the amplitude of echo energy from potentially identical motion trajectories through trajectory search, also known as long-term non-coherent accumulation. They do not have strict coherence requirements for the system and are relatively simple to implement in engineering. However, their signal accumulation efficiency and SNR improvement are significantly lower than coherent accumulation methods, making them unsuitable for detecting weak moving targets in complex environments. The other type is coherent algorithms, such as Keystone transform. These algorithms perform scale transformation on the original coordinate axes through interpolation, effectively correcting for cross-range cell movement caused by target motion. However, for targets exhibiting Doppler blur, Keystone transform requires searching for the blur number.

[0004] For high-speed moving targets, the conventional algorithms in the above-mentioned existing technologies use the traditional stop-and-go model to model the echo.

[0005] The linear frequency modulated pulse signal transmitted by the radar is represented as:

[0006]

[0007] in, T represents a fast-time variable. p Indicates pulse width, f c K represents the carrier frequency, and K represents the frequency modulation slope.

[0008] For the traditional stop-and-go model, the instantaneous slant range of the target relative to the radar can be expressed as:

[0009] R(t m )=R0+vt m (2)

[0010] Where R0 represents the target's initial radial distance; v represents the target's initial radial velocity; t m =mT r (m = 0, 1, 2, ..., M-1) represents the slow time variable, M represents the number of pulses, and T represents the time variable. r This indicates the pulse repetition interval.

[0011] The target echo signal under the stationary model can be expressed as:

[0012]

[0013] Among them, t m =mT r (m = 0, 1, 2, ..., M-1) represents the slow time variable, M represents the number of pulses, and T represents the time variable. r Indicates the pulse repetition interval; τ represents a fast-time variable; m =2R(t) m ) / c, where T represents the time delay of the m-th pulse, and c is the speed of light; p Indicates pulse width; K represents frequency modulation slope; f c Indicates the carrier frequency.

[0014] The instantaneous slant range of the target within the stop-and-go model is a variable that changes with t. m The sequence changes with the changes, that is, it only considers the positional changes caused by the target motion between adjacent pulses.

[0015] It can be seen that the above algorithms still have certain shortcomings, namely, they only process echoes under the traditional stop-and-go model, ignoring the target's intra-pulse motion within a pulse duration. High-speed moving targets in the stop-and-go model exhibit scale transformations of contraction or stretching, resulting in a mismatch with the transmitted reference signal. This leads to main lobe broadening and shift in the pulse compression output, affecting the performance of traditional matched filtering algorithms. Therefore, these algorithms are only suitable for narrowband signals or low-speed moving targets. Thus, a new echo signal processing method is needed for Doppler pulse radar systems to achieve ultra-high-speed target detection. Summary of the Invention

[0016] The purpose of this invention is to provide a method, system, and apparatus for processing the echo signal of a high-speed target in the case of Doppler pulse radar detecting a long-range high-speed target. This invention can effectively solve the problem of range migration of high-speed target echoes and the mismatch filtering caused by echo scale transformation, thereby more accurately estimating the target speed and range information.

[0017] Specifically, on the one hand, the present invention provides a method for processing ultra-high-speed target echo signals, comprising:

[0018] Constructing a reference signal: Divide the possible radial velocity range of a high-speed target into multiple velocity levels, and in each velocity level v i In this process, a corresponding reference signal is constructed;

[0019] Matched filtering: at each speed range v i In the process, the range-dimensional spectrum of the target echo from the intrapulse motion model is multiplied by the conjugate of the reference signal to obtain the frequency domain pulse compression result: when the velocity level v i When the value is equal to the radial velocity of the target, the reference signal matches the echo signal;

[0020] Construct the migration phase compensation function: at each speed level v i In the process, a migration phase compensation function is constructed to perform slow-time phase compensation and eliminate range migration in the target echo;

[0021] Range-dimensional IFFT: Performs range-dimensional IFFT processing on the echo signal after migration phase compensation;

[0022] MTD processing: Perform MTD processing on the output signal of the distance-dimensional IFFT.

[0023] Furthermore, the range-dimensional spectrum of the target echo in the intrapulse motion model is:

[0024]

[0025] Among them, t m Represents a slow-time variable; f represents a fast-time variable; The corresponding distance-frequency variable; f d The target Doppler frequency is represented by α = 1 - 2v / c, the scaling factor is represented by K, and the frequency modulation slope is represented by T. p Indicates the transmission signal duration; f c Indicates the carrier frequency of the transmitted signal; τ m =2R(t) m ) / c represents the delay of the m-th pulse.

[0026] Furthermore, the reference signal S ref2 (f) is:

[0027]

[0028] Among them, f di =-2v i / λ indicates the speed range (v). i The corresponding Doppler frequency; α i =1-2v i / c indicates the speed setting (v). i The corresponding scaling factor; f represents The corresponding distance-frequency variable; K represents the frequency modulation slope; T p Indicates the transmission signal duration.

[0029] Furthermore, the principle for determining the value of the multiple speed gaps Δv is that the resulting distance migration does not exceed one distance gate during the entire coherent accumulation time T, i.e. Where c is the speed of light; B is the bandwidth of the echo signal.

[0030] Furthermore, the migration phase compensation function is:

[0031]

[0032] Among them, t m =mT r (m = 0, 1, 2, ..., M-1) represents the slow-time variable; f represents... The corresponding distance-frequency variable; f c Indicates carrier frequency; α i =1-2v i / c is the speed setting (V). i The scale transformation factor; c is the speed of light.

[0033] Furthermore, after MTD processing, the process also includes: obtaining the speed information corresponding to the maximum MTD peak value based on the processing results of each speed range, and using it as the target speed information.

[0034] Furthermore, after MTD processing, the actual target distance is calculated based on the distance coordinates corresponding to the main MTD peak. Right now Where α is the scaling factor; This represents the distance value corresponding to the main peak on the MTD plane.

[0035] On the other hand, the present invention also provides an ultra-high-speed target echo signal processing system for implementing the above-mentioned ultra-high-speed target echo signal processing method, including an echo generation module, a matched filtering module, a migration compensation module and an MTD module;

[0036] The echo generation module generates ultra-high-speed target echoes under the intra-pulse motion model.

[0037] The matched filtering module constructs a reference signal and uses the reference signal to perform matched filtering on the ultra-high-speed target echo.

[0038] The migration compensation module constructs a migration phase compensation function and uses the compensation function to eliminate the range migration of the ultra-high speed target echo.

[0039] The MTD module is used for slow-time FFT processing.

[0040] In another aspect, the present invention also provides an ultra-high-speed target echo signal processing device: the device includes a memory and a processor; the memory stores a computer program for implementing an ultra-high-speed target echo signal processing method, and the processor executes the computer program to implement the steps of the above method.

[0041] The beneficial effects of the ultra-high-speed target echo signal processing method of the present invention are as follows:

[0042] For the detection of long-range hypersonic targets by Doppler pulse radar, the signal detection method for hypersonic targets proposed in this invention, compared with conventional algorithms, focuses on the influence of the hypersonic target's intrapulse motion, and establishes a more accurate echo model through multi-speed-level processing. It also proposes an effective matched filtering algorithm to achieve coherent accumulation of echoes and target detection, effectively solving the range migration problem of high-speed target echoes and the mismatch filtering caused by echo scale transformation. This results in a more accurate estimation of target velocity and range information, and has strong practical application value.

[0043] This invention achieves pulse compression by constructing a specific reference signal and matching it with a constructed accurate echo model, thereby avoiding the main peak broadening and shifting phenomena that occur when using traditional reference signals to achieve pulse compression.

[0044] This invention divides the possible radial motion speed range of a high-speed target into multiple speed ranges, which can find a more accurate target speed value and use it to construct a reference signal and a migration phase compensation function, thereby realizing matched filtering and range migration correction respectively.

[0045] This invention employs phase compensation to compensate for the range migration phenomenon in ultra-high-speed target echoes caused by the coupling phase between slow time and range frequency, thereby correcting the range migration and avoiding performance loss due to coherent accumulation. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the system composition of the present invention.

[0047] Figure 2 This is a flowchart of the method of the present invention.

[0048] Figure 3 This is a schematic diagram of the pulse compression processing result of the target echo signal under conventional algorithms in the existing technology.

[0049] Figure 4 This is a schematic diagram illustrating the distance migration phenomenon of the target echo signal under conventional algorithms in existing technologies.

[0050] Figure 5 This is a schematic diagram of the MTD result of the target echo signal under conventional algorithms in existing technologies.

[0051] Figure 6 This is a schematic diagram of the pulse compression processing results of the target echo signal at each speed level in this embodiment.

[0052] Figure 7 This is a schematic diagram of the pulse compression processing result of target 1 under the pulse compression and target detection algorithm of this embodiment.

[0053] Figure 8 This is a schematic diagram of the trajectory of target 1 after echo migration correction under the pulse compression and target detection algorithm of this embodiment.

[0054] Figure 9 This is a schematic diagram of the MTD result of the echo of target 1 under the pulse compression and target detection algorithm of this embodiment.

[0055] Figure 10 This is a schematic diagram of the pulse compression processing result of target 2 under the pulse compression and target detection algorithm in this embodiment.

[0056] Figure 11 This is a schematic diagram of the trajectory of the target 2 echo signal after phase compensation under the pulse compression and target detection algorithm in this embodiment.

[0057] Figure 12 This is a schematic diagram of the MTD result of the echo signal of target 2 under the pulse compression and target detection algorithm in this embodiment.

[0058] Figure 13 This is a schematic diagram of the target's MTD result under conventional algorithms in existing technologies in a noisy environment.

[0059] Figure 14 This is a schematic diagram showing the pulse compression processing results of the target echo signal at various speed levels under the pulse compression and target detection algorithm of this embodiment in a noisy environment.

[0060] Figure 15 This is a schematic diagram of the MTD result of the echo signal of target 1 under the pulse compression and target detection algorithm of this embodiment in a noisy environment.

[0061] Figure 16 This is a schematic diagram of the MTD result of the echo signal of target 2 under the pulse compression and target detection algorithm of this embodiment in a noisy environment. Detailed Implementation

[0062] The present invention will now be described in further detail with reference to the embodiments and the accompanying drawings.

[0063] Example 1:

[0064] For situations involving Doppler pulse radar detecting long-range hypersonic targets, this invention employs an intra-pulse motion model to more accurately model the echo signal of a high-speed moving target. One embodiment of this invention provides a method and system for processing hypersonic target echo signals. Figure 1 As shown, the ultra-high-speed target echo signal processing system of this embodiment includes an echo generation module, a matched filtering module, a migration compensation module, and an MTD module. The echo generation module generates ultra-high-speed target echoes under an intra-pulse motion model; the matched filtering module performs matched filtering on the echoes using a reference signal; the migration compensation module eliminates echo distance migration using a migration phase compensation function; and the MTD module performs slow-time FFT (fast Fourier transform) processing to achieve coherent accumulation.

[0065] The instantaneous slant range of the target relative to the radar under the intra-pulse motion model is determined simultaneously by the fast and slow time, expressed as:

[0066] R(t)=R0+vt (4)

[0067] Where R0 represents the initial radial distance of the target; v represents the initial radial velocity of the target; Represents a full-time variable. Represents a fast-time variable, t m =mT r (m = 0, 1, 2, ..., M-1) represents the slow time variable, M represents the number of pulses, and T represents the time variable. r This indicates the pulse repetition interval.

[0068] Replace R(t) in equation (3) with R(t) in equation (4). m (where R(t)) m )=cτ m / 2), the time-domain target echo signal under the intrapulse motion model can be expressed as:

[0069]

[0070] in, Represents a fast-time variable, t m =mT r (m = 0, 1, 2, ..., M-1) represents the slow time variable, M represents the number of pulses, and T represents the time variable. r Indicates the pulse repetition interval; τ m =2R(t) m ) / c, where T represents the time delay of the m-th pulse, and c is the speed of light; p The pulse width is represented by α = 1 - 2v / c, which is the scale transformation factor, where v represents the target's initial radial velocity; f d=-2v / λ, where λ = c / f is the Doppler frequency of the target. c , is the wavelength of the transmitted signal, f c Indicates the carrier frequency.

[0071] Comparing the echoes of the traditional stop-and-go model with those of the intrapulse motion model of the present invention (Equations (3) and (5)), it can be seen that the target echo pulse width and time delay have changed under the intrapulse motion model compared to the stop-and-go model, as shown in the table below.

[0072] parameter Stop and go model Intravascular motion model Pulse delay <![CDATA[τ m ]]> <![CDATA[τ m / a]]> Pulse width <![CDATA[T p ]]> <![CDATA[T p / a]]>

[0073] Calculate the width difference ΔT between the transmitted and received pulses. p :

[0074]

[0075] Among them, T p The pulse width is represented by α = 1 - 2v / c, which represents the scale transformation factor, v represents the initial radial velocity of the target, and c is the speed of light.

[0076] Therefore, when the width difference ΔT p Greater than That is, the target's initial radial velocity is greater than At this time, the deformation of the echo cannot be ignored, which will affect conventional pulse compression and target detection. B is the bandwidth of the echo signal.

[0077] To address the significant impact of high-speed target echo waveform variations on conventional pulse compression and target detection, the signal processing method for ultra-high-speed target echoes in this invention employs an improved pulse compression and target detection algorithm based on multi-speed-level processing for pulse compression processing, such as... Figure 2 As shown. The specific process includes:

[0078] 1. Construct a reference signal.

[0079] The range-dimensional spectrum S of the target echo in the intrapulse motion model r2 (t m f) can be obtained from the following formula:

[0080]

[0081] Among them, t m Represents a slow-time variable; f represents a fast-time variable; The corresponding distance-frequency variable; f d The target Doppler frequency is represented by α = 1 - 2v / c, the scaling factor is represented by K, and the frequency modulation slope is represented by T. p Indicates the transmission signal duration; f c Indicates the carrier frequency of the transmitted signal; τm =2R(t) m ) / c represents the delay of the m-th pulse.

[0082] As can be seen from equation (7), compared with the echo spectrum under the traditional stop-and-go model, the echo spectrum under the pulse motion model exhibits Doppler frequency shift and scale transformation. In order to achieve matched filtering, a specific reference signal needs to be constructed.

[0083] The possible radial velocity range of a high-speed target (e.g., assuming a possible radial velocity range of 0 m / s to 9000 m / s) is divided into multiple velocity levels. The principle for determining the value of the interval Δv between each velocity level is that the resulting range migration does not exceed one range threshold over the entire coherent accumulation time T. (For example, take Δv = 100 m / s). Through the matched filter module, at each speed range v... i In the above, construct the following reference signal S. ref2 (f):

[0084]

[0085] Among them, f di =-2v i / λ indicates the speed range (v). i The corresponding Doppler frequency; α i =1-2v i / c indicates the speed setting (v). i The corresponding scaling factor; f represents The corresponding distance-frequency variable; K represents the frequency modulation slope; T p Indicates the transmission signal duration.

[0086] The reference signal can be constructed by the echo generation module.

[0087] It is understood that the ultra-high-speed target echo signal processing method and system of the present invention can also be used for ultra-high-speed target frequency domain echo signals. In this case, it is no longer necessary to perform range dimension FFT on them, and speed classification can be performed directly.

[0088] 2. Matched filtering.

[0089] Using the reference signal S constructed above ref2 (f), at each speed gear v i In the process, the range dimension spectrum S of the target echo in the intrapulse motion model is... r2 (t m f(the time-domain target echo signal obtained by range-dimensional FFT processing) and the reference signal S ref2 (f) conjugate S ref2 *(f) Multiplying these components yields the echo frequency domain pulse compression result S. c2 (t m ,f):

[0090]

[0091] When v i =v, that is, speed gear v i The value of is equal to the radial velocity of the target. With the reference signal matching the echo, we can obtain:

[0092]

[0093] Where f represents The corresponding distance-frequency variable; f d The target Doppler frequency is represented by α = 1 - 2v / c, the scaling factor is represented by K, and the frequency modulation slope is represented by T. p Indicates the transmission signal duration; f c Indicates the carrier frequency of the transmitted signal; τ m =2R(t) m ) / c represents the time delay of the m-th pulse.

[0094] 3. Construct the migration phase compensation function.

[0095] To prevent distance migration, at each speed level v i In this process, a migration phase compensation function is constructed to perform slow-time phase compensation and eliminate range migration in the target echo.

[0096] A migration phase compensation function is constructed using a migration compensation module for S. c2 (t m f) Performing slow-time phase compensation, we can obtain:

[0097] S c3 (t m f) = S c2 (t m ,f)H(t m f) (11)

[0098] in, For the migrating phase compensation function; t m =mT r (m = 0, 1, 2, ..., M-1) represents the slow-time variable; f represents... The corresponding distance-frequency variable; f c Indicates carrier frequency; α i =1-2v i / c is the speed setting (V). i The scale transformation factor; c is the speed of light.

[0099] When v i When v = 0, the range migration caused by the target's hypersonic motion will be corrected. At this point, the echo frequency domain pulse compression result can be expressed as:

[0100]

[0101] Among them, t m =mT r (m = 0, 1, 2, ..., M-1) represents the slow time variable, and M represents the number of pulses. f represents a fast-time variable; The corresponding distance-frequency variable; f d =-2v / λ, where λ = c / f is the Doppler frequency of the target. c λ is the wavelength; c is the speed of light; α = 1 - 2v / c is the scale transformation factor; K represents the frequency modulation slope; T p Indicates pulse width; f c R0 represents the initial radial distance of the target, where R represents the carrier frequency.

[0102] Conventional algorithms typically employ a combination of velocity ambiguity number search and Keystone transform to sequentially correct range migration caused by both velocity ambiguity and baseband velocity. However, the compensation function constructed in this invention eliminates the need for additional velocity ambiguity correction, directly utilizing the velocity gate values ​​during pulse compression to directly correct range migration. Experimental simulations show that the maximum unambiguous target velocity in this embodiment is 0.67 m / s, significantly smaller than the velocity gate spacing Δv (100 m / s) used to construct the reference signal during pulse compression. Therefore, the range migration caused during the accumulation time is far less than that of a single range gate.

[0103] The compensation function can be constructed by the migration compensation module.

[0104] 4. Distance-dimensional IFFT.

[0105] If the echo signal after migration phase compensation is processed by range-dimensional IFFT, the echo pulse compression result can be expressed as:

[0106]

[0107] Among them, t m Represents a slow-time variable; Represents a fast-time variable; A1 is the signal amplitude; f represents... The corresponding distance-frequency variable; S c3 (t m f) represents the echo frequency domain pulse compression result; α = 1 - 2v / c represents the scaling factor; K represents the frequency modulation slope; T p Indicates the transmission signal duration; R0 represents the initial radial distance of the target; fd Indicates the target Doppler frequency.

[0108] 5. MTD processing.

[0109] The output signal from the previous step is processed by MTD (Mean Transmission Method) to obtain estimated distance and velocity values ​​for the target. The specific process includes:

[0110] At each speed gear v i In China, Perform the following MTD processing (slow-time FFT processing) and output the peak value of MTD. When v i =v, that is, speed gear v i The value is equal to the radial velocity of the target, that is:

[0111]

[0112] Among them, f m Indicates t m The corresponding azimuth frequency variable; t represents a fast-time variable; m =mT r (m = 0, 1, 2, ..., M-1) represents the slow time variable, M represents the number of pulses, and T represents the time variable. r Indicates the pulse repetition interval; α = 1 - 2v / c is the scaling factor; K represents the frequency modulation slope; T p Indicates pulse width; R0 represents the initial radial distance of the target; f d =-2v / λ, where λ = c / f is the Doppler frequency of the target. c , is the wavelength.

[0113] Based on the maximum MTD peak value from the processing results of each speed range, the speed information corresponding to the maximum MTD peak value is obtained as the target's speed information. Furthermore, based on the distance coordinates corresponding to the main MTD peak value, the measured true target distance is calculated. Right now in This represents the distance value corresponding to the main peak on the MTD plane.

[0114] In this embodiment, two high-speed moving targets are set, with initial radial distances of 2000km and 2020km between them and the radar, and initial radial velocities of Mach 10 and Mach 20, respectively. Simultaneously, when processing using this method, the velocity ranges are set to 0m / s, 100m / s, 200m / s…, 9000m / s.

[0115] To facilitate observation of the target migration trajectory and pulse compression results, and to verify the effectiveness of the signal processing method for ultra-high-speed target echoes of the present invention, this embodiment compares the results obtained using conventional algorithms in the prior art and the signal processing method for ultra-high-speed target echoes of the present invention under an ideal noise-free environment.

[0116] The processing results of the two ultra-high-speed target callback signals using the conventional pulse compression MTD algorithm are as follows: Figures 3-5 As shown. Figure 3 The pulse compression results of the first echo pulse using the conventional pulse compression MTD algorithm are presented. It can be seen that due to the mismatch between the reference signal and the deformed target echo, the pulse compression results show main lobe displacement and broadening. Figure 4 The time-domain results of the two-dimensional pulse compression after data rearrangement are presented. It can be seen that due to the high-speed movement of the target, the echo exhibits range migration, crossing multiple range gates. Figure 5 The MTD results of the target echo are given. It can be seen that due to pulse compression, main lobe broadening, and range migration, the accumulation performance is very poor and the target cannot be detected.

[0117] The processing results of the two hypersonic target echo signals using the hypersonic target echo signal processing method of this embodiment are as follows: Figures 6-12 As shown. Figure 6 The output results for each speed setting are given, and the two peak values ​​clearly show that there are two targets.

[0118] Figure 7 , Figure 8 , Figure 9 The pulse compression, migration-corrected trajectory, and MTD results of the echo from target 1 at a velocity setting of 3400 m / s are presented respectively. Comparison Figure 3 and Figure 7 As can be seen, by constructing a reference signal matched to the echo, the signal processing method for ultra-high-speed target echoes of the present invention can effectively achieve matched filtering, prevent main lobe broadening, and improve the main peak by 1.38 dB. Furthermore, by constructing a compensation function, the signal processing method for ultra-high-speed target echoes of the present invention can also correct for target range migration, thereby improving the cumulative gain of MTD and achieving target detection.

[0119] Figure 10 , Figure 11 , Figure 12 The pulse compression, migration trajectory, and MTD results of the target 2 echo at a velocity range of 6800 m / s are presented. It can be seen that the signal processing method for ultra-high-speed target echoes of this invention can effectively accumulate the signal, with the pulse compression peak improved by 4.6 dB compared to conventional methods.

[0120] Furthermore, to make the simulation more realistic, noise effects were incorporated. In a noisy environment with a signal-to-noise ratio of -40dB, the processing results using conventional target detection algorithms in existing technologies are as follows: Figure 13 As shown; the processing result of the signal processing method for ultra-high-speed target echo of the present invention is as follows. Figure 14 , Figure 15 , Figure 16 As shown, conventional target detection algorithms in the prior art cannot accumulate target energy because they do not consider the effects of echo waveform variation and range migration. However, the signal processing method for the ultra-high-speed target echo of this invention can effectively focus on both targets and can estimate the distance and velocity of the ultra-high-speed target more accurately.

[0121] In some embodiments, certain aspects of the above-described techniques may be implemented by one or more processors of a processing system executing software. The software includes one or more sets of executable instructions stored or otherwise tangibly implemented on a non-transitory computer-readable storage medium. The software may include instructions and certain data that, when executed by one or more processors, manipulate one or more processors to perform one or more aspects of the above-described techniques. The non-transitory computer-readable storage medium may include, for example, magnetic or optical disk storage devices, solid-state storage devices such as flash memory, cache, random access memory (RAM), or other non-volatile memory devices. The executable instructions stored on the non-transitory computer-readable storage medium may be source code, assembly language code, object code, or other instruction formats interpreted or otherwise executed by one or more processors.

[0122] Computer-readable storage media can include any storage medium or combination of storage media that can be accessed by a computer system during use to provide instructions and / or data to the computer system. Such storage media can include, but are not limited to, optical media (e.g., optical discs (CDs), digital versatile optical discs (DVDs), Blu-ray discs), magnetic media (e.g., floppy disks, magnetic tapes, or magnetic hard disks), volatile memory (e.g., random access memory (RAM) or cache), non-volatile memory (e.g., read-only memory (ROM) or flash memory), or microelectromechanical systems (MEMS) based storage media. Computer-readable storage media can be embedded in a computing system (e.g., system RAM or ROM), fixedly attached to a computing system (e.g., a magnetic hard disk drive), removably attached to a computing system (e.g., an optical disc or universal serial bus-based (USB) flash memory), or coupled to a computer system via a wired or wireless network (e.g., network-accessible storage (NAS)).

[0123] While the present invention has been disclosed above with reference to preferred embodiments, these embodiments are not intended to limit the invention. Any equivalent changes or modifications made without departing from the spirit and scope of the invention are also within the scope of protection of the invention. Therefore, the scope of protection of the present invention should be determined by the claims of this application.

Claims

1. A method for processing ultra-high-speed target echo signals, characterized in that, include: Constructing a reference signal: Divide the possible radial motion velocity range of the high-speed target into multiple velocity levels, and for each velocity level v i Construct the corresponding reference signal; the principle for determining the value of the multiple speed gaps Δv is that the resulting distance migration does not exceed one distance gate during the entire coherent accumulation time T, i.e. Where c is the speed of light; B is the bandwidth of the echo signal; Matched filtering: for each speed range v i Multiplying the range-dimensional spectrum of the target echo from the intrapulse motion model with the conjugate of the reference signal yields the frequency-domain pulse compression result: when the velocity level v i When the value is equal to the radial velocity of the target, the reference signal matches the echo signal; Construct the migration phase compensation function: for each speed range v i Construct a migration phase compensation function, perform slow-time phase compensation, and eliminate range migration in the target echo; Range-dimensional IFFT: Performs range-dimensional IFFT processing on the echo signal after migration phase compensation; MTD processing: Perform MTD processing on the output signal of the distance-dimensional IFFT.

2. The ultra-high-speed target echo signal processing method according to claim 1, characterized in that, The range dimension spectrum of the target echo in the intrapulse motion model is: Among them, t m =mT r T represents the slow-time variable, m = 0, 1, 2, ..., M-1, where M represents the number of pulses. r Indicates the pulse repetition interval; f represents a fast-time variable; The corresponding distance-frequency variable; f d The value represents the target's Doppler frequency; α = 1 - 2v / c represents the scale transformation factor, v represents the target's initial radial velocity, and c is the speed of light; K represents the frequency modulation slope; T p Indicates the transmission signal duration; f c Indicates the carrier frequency of the transmitted signal; τ m =2R(t) m ) / c, representing the time delay of the m-th pulse, R(t) m ) indicates that at t m The instantaneous slant range of the target relative to the radar at any given moment.

3. The ultra-high-speed target echo signal processing method according to claim 1, characterized in that, The reference signal S ref2 (f) is: Among them, f di =-2v i / λ indicates the speed range (v). i The corresponding Doppler frequency, λ is the wavelength of the transmitted signal; α i =1-2v i / c indicates the speed setting (v). i The corresponding scale transformation factor, where c is the speed of light; f represents... The corresponding distance-frequency variable; K represents the frequency modulation slope; T p Indicates the transmission signal duration.

4. The ultra-high-speed target echo signal processing method according to claim 1, characterized in that, The migration phase compensation function is: Among them, t m =mT r T represents the slow-time variable, m = 0, 1, 2, ..., M-1, where M represents the number of pulses. r Indicates the pulse repetition interval; f represents The corresponding distance-frequency variable; f c Indicates carrier frequency; α i =1-2v i / c is the speed setting (V). i The scale transformation factor is denoted by ; c is the speed of light.

5. The ultra-high-speed target echo signal processing method according to claim 1, characterized in that, The process after MTD processing also includes: obtaining the speed information corresponding to the maximum MTD peak value based on the processing results of each speed range, which is then used as the target speed information.

6. The ultra-high-speed target echo signal processing method according to claim 1, characterized in that, The process following MTD processing also includes: calculating the true target distance based on the distance coordinates corresponding to the main MTD peak. Right now Where α is the scaling factor; This represents the distance value corresponding to the main peak on the MTD plane.

7. A high-speed target echo signal processing system, used to implement the high-speed target echo signal processing method according to any one of claims 1-6, characterized in that, It includes an echo generation module, a matched filter module, a migration compensation module, and an MTD module; The echo generation module generates ultra-high-speed target echoes under the intra-pulse motion model. The matched filtering module constructs a reference signal and uses the reference signal to perform matched filtering on the ultra-high-speed target echo. The migration compensation module constructs a migration phase compensation function and uses the migration phase compensation function to eliminate the range migration of the ultra-high speed target echo. The MTD module is used for slow-time FFT processing.

8. A device for processing ultra-high-speed target echo signals, characterized in that, The device includes a memory and a processor; the memory stores a computer program for implementing a method for processing ultra-high-speed target echo signals, and the processor executes the computer program to implement the steps of the method according to any one of claims 1-6.

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