CN-122017770-A - Maneuvering target detection method and device based on long-time coherent accumulation

CN122017770ACN 122017770 ACN122017770 ACN 122017770ACN-122017770-A

Abstract

The application provides a maneuvering target detection method and device based on long-time coherent accumulation, belonging to the technical field of target detection, wherein the method comprises the steps of firstly obtaining a baseband echo signal, then carrying out pulse compression to obtain a time domain pulse pressure signal, and initializing a distance and speed fuzzy number search parameter; then, introducing new slow time variable to the fast time frequency domain signal to carry out Keystone transformation to obtain a distance corrected signal, then, carrying out track search based on Radon transformation to the corrected slow time domain signal, finally, traversing all distance and speed fuzzy numbers, carrying out coherent accumulation to each searched track by a PCFCRD method, estimating acceleration and outputting a target detection result. Compared with the traditional method, the method reduces the calculation complexity.

Inventors

LIU WEI
LI AIHUA
BAI JIAN
WANG YUHANG
ZHANG WANYU
WANG HAO
XU WENWEN
CAO JIANYIN

Assignees

北京遥感设备研究所

Dates

Publication Date: 20260512
Application Date: 20251230

Claims (10)

1. A maneuvering target detection method based on long-time coherent accumulation, comprising: down-converting and moving the echo signal to a baseband frequency to obtain a baseband echo signal; performing pulse compression on the baseband echo signal to obtain a time domain echo signal, and initializing a distance searching range and a speed fuzzy number searching range; Performing fast time dimension Fourier transform on the time domain echo signals to obtain fast time frequency domain signals; introducing a slow time variable to perform Keystone transformation on the fast time frequency domain signal to obtain a corrected fast time frequency domain signal; Performing inverse fast fourier transform on the corrected fast time frequency domain signal to obtain a corrected time domain signal; Carrying out track search based on Radon on the corrected time domain signal based on a search initialization search range and a speed fuzzy number search range to obtain a plurality of track signals; performing coherent accumulation on each track signal through a parameterized center frequency-frequency modulation distribution algorithm, and estimating acceleration; and outputting a target detection result based on the coherent accumulation result corresponding to each track signal.
2. A method for detecting a maneuver object based on long-term coherent accumulation as defined in claim 1 wherein said coherent accumulation of each of the track signals by a parameterized center frequency-frequency modulated distribution algorithm comprises: for each track signal, the following is performed: determining a correlation function comprising a delay variable and a constant delay based on the trajectory signal; Performing non-uniform Fourier transform on delay variables in the correlation function to realize energy aggregation on the delay variables; performing line demodulation processing on the signals after energy aggregation to obtain linear phase signals corresponding to the track signals so as to eliminate the influence of secondary phases; and carrying out Fourier transformation on the linear phase signal corresponding to the track signal so as to realize coherent accumulation of the track signal.
3. The maneuvering target detection method based on long-time coherent accumulation according to claim 1, wherein the time domain echo signal is expressed as: Wherein a 0 is signal amplitude, λ is signal wavelength, c is light speed, sinc (x) =sin (pi x)/pi x, a singer function is represented, B is signal bandwidth, t is fast time, t m is slow time, R 0 is initial radial distance, v 0 is non-fuzzy speed, n is speed fuzzy number, v m is blind speed, and a is acceleration.
4. The maneuvering target detection method based on long-time coherent accumulation according to claim 1, wherein the fast time frequency domain signal is expressed as: Wherein f is a fast time frequency, f c is a carrier frequency, rect is a rectangular window function, A 0 is a signal amplitude, B is a signal bandwidth, n is a speed ambiguity number, v m is a blind speed, a is acceleration, c is a light speed, R 0 is an initial radial distance, and t m is a slow time.
5. The method for detecting a maneuver target based on long term coherent accumulation as defined in claim 4 wherein said slow time variable is Introducing a slow time variable to perform Keystone transformation on the fast time frequency domain signal, and obtaining a corrected fast time frequency domain signal which is expressed as:
6. The method for detecting a maneuver object based on long-term coherent accumulation as defined in claim 5 wherein said corrected time domain signal is represented as:
7. The method for detecting a maneuvering target based on long-time coherent accumulation according to claim 6, wherein the process of performing track search on the corrected time domain signal based on a search initialization search range and a speed ambiguity search range is implemented based on the following formula: where n s is the speed ambiguity of the search and R s is the initial distance of the search.
8. A maneuvering target detecting device based on long-time coherent accumulation, characterized by comprising: The baseband conversion module is used for down-converting and moving the echo signals to baseband frequency to obtain baseband echo signals; the initialization module is used for carrying out pulse compression on the baseband echo signals to obtain time domain echo signals, and initializing a distance searching range and a speed fuzzy number searching range; The Fourier transform module is used for carrying out fast time dimension Fourier transform on the time domain echo signals to obtain fast time frequency domain signals; The correction module is used for introducing a slow time variable to perform Keystone transformation on the fast time frequency domain signal to obtain a corrected fast time frequency domain signal; The inverse Fourier transform module is used for carrying out inverse Fourier transform on the corrected fast time frequency domain signal to obtain a corrected time domain signal; The track searching module is used for carrying out track searching based on Radon on the corrected time domain signal based on a searching initialization searching range and a speed fuzzy number searching range to obtain a plurality of track signals; The coherent accumulation module is used for carrying out coherent accumulation on each track signal through a parameterized center frequency-frequency modulation distribution algorithm and estimating acceleration; And the result output module is used for outputting a target detection result based on the coherent accumulation result corresponding to each track signal.
9. An electronic device comprising a memory, a processor and a computer program stored in the memory and running on the processor, characterized in that the processor implements the steps of the method according to any of claims 1 to 7 when the computer program is executed.
10. A computer readable storage medium storing a computer program, characterized in that the computer program when executed by a processor implements the steps of the method according to any one of claims 1 to 7.

Description

Maneuvering target detection method and device based on long-time coherent accumulation Technical Field The application belongs to the technical field of target detection, and particularly relates to a maneuvering target detection method and device based on long-time coherent accumulation. Background Targets such as unmanned aerial vehicles, near-space vehicles and the like typically have a small radar cross section, echo signals thereof typically have a low signal-to-noise ratio, and may even be completely submerged in background noise and clutter, which presents a great challenge for efficient detection by radar systems. In order to improve the detection performance of weak and high maneuvering targets, long-time coherent accumulation technology is generated. The method can improve the signal-to-noise ratio of the target signal by accumulating the coherent signal energy in a longer observation period. However, to achieve efficient coherent accumulation, the target signal needs to be concentrated in a fixed range-doppler cell throughout the accumulation. For a maneuvering target, its acceleration and velocity may cause Range shifts (RM) and doppler frequency shifts (Doppler Frequency Migration, DFM), thereby breaking energy focus, resulting in a decrease in the cumulative gain of conventional moving target detection (Moving Target Detection, MTD) algorithms. Therefore, how to effectively compensate RM and DFM in long-term accumulation process is one of the key problems of realizing accurate detection of small maneuver targets. In recent years, for a uniform acceleration moving object, researchers propose a plurality of detection methods based on multidimensional parameter joint search. Typical algorithms include generalized Radon Fourier transform (Generalized Radon-Fourier Transform, GRFT), radon-fractional Fourier transform (Radon-Fractional Fourier Transform, RFRFT), and Radon-Lv's Distribution (RLVD), among others. Among them, GRFT is the most representative method that compensates RM by three-dimensional parameter search, and extracts a target trajectory, and then constructs a doppler matched filter to correct DFM, achieving coherent accumulation. RFRFT and RLVD utilize the characteristic that target slow time dimension signals can be modeled as linear frequency modulation (Linear Frequency Modulation, LFM) waveforms, and coherent accumulation is realized by means of a combined time-frequency analysis technology FRFT and LVD. Although the above method achieves good effect in terms of detection performance, it relies on exhaustive search of high-dimensional parameter space, resulting in higher algorithm computation complexity, which becomes a major bottleneck for practical deployment and engineering application. Disclosure of Invention The application aims to provide a maneuvering target detection method and device based on long-time coherent accumulation, so as to reduce the computational complexity. In a first aspect of an embodiment of the present application, there is provided a maneuvering target detecting method based on long-time coherent accumulation, including: down-converting and moving the echo signal to a baseband frequency to obtain a baseband echo signal; performing pulse compression on the baseband echo signals to obtain time domain echo signals, and initializing a distance searching range and a speed fuzzy number searching range; performing fast time dimension Fourier transform on the time domain echo signals to obtain fast time frequency domain signals; introducing a slow time variable to perform Keystone transformation on the fast time frequency domain signal to obtain a corrected fast time frequency domain signal; performing inverse fast Fourier transform on the corrected fast time frequency domain signal to obtain a corrected time domain signal; Track searching based on Radon is carried out on the corrected time domain signals based on a searching initialization searching range and a speed fuzzy number searching range, so that a plurality of track signals are obtained; performing coherent accumulation on each track signal through a parameterized center frequency-frequency modulation distribution algorithm, and estimating acceleration; and outputting a target detection result based on the coherent accumulation result corresponding to each track signal. In a second aspect of the embodiments of the present application, there is provided a maneuvering target detecting device based on long-time coherent accumulation, including: The baseband conversion module is used for down-converting and moving the echo signals to baseband frequency to obtain baseband echo signals; the initialization module is used for carrying out pulse compression on the baseband echo signals to obtain time domain echo signals, and initializing a distance searching range and a speed fuzzy number searching range; the Fourier transform module is used for carrying out fast time dimension Fourier transform on the time do