CN-121995334-A - Ground sea clutter identification and suppression method and equipment based on clutter power spectrum estimation

CN121995334ACN 121995334 ACN121995334 ACN 121995334ACN-121995334-A

Abstract

The invention discloses a land-sea clutter recognition and suppression method and equipment based on clutter power spectrum estimation, and relates to the technical field of radar clutter suppression, wherein the method comprises the steps of obtaining clutter data from radar echo data; the method comprises the steps of processing clutter data to obtain normalized clutter power spectrum density, fitting the normalized clutter power spectrum density to obtain clutter power spectrum center frequency and clutter power spectrum frequency spectrum width, identifying land and sea clutter types according to clutter power spectrum center frequency and clutter power spectrum frequency spectrum width and combining preset ground clutter and sea clutter threshold parameters, calculating Doppler filter coefficients based on the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width, and carrying out Doppler filtering processing on the clutter data by using the Doppler filter coefficients to complete land and sea clutter suppression. The invention can adaptively distinguish ground clutter from sea clutter, and realizes more accurate and deep suppression of the ground clutter.

Inventors

XIA YONGHONG
GUO XIANGLEI
MA TENG
LIU MEIQI

Assignees

北京无线电测量研究所

Dates

Publication Date: 20260508
Application Date: 20260115

Claims (10)

1. The method for identifying and suppressing the ground sea clutter based on clutter power spectrum estimation is characterized by comprising the following steps of: Obtaining clutter data from radar echo data; processing the clutter data to obtain normalized clutter power spectrum density; fitting the normalized clutter power spectrum density to obtain clutter power spectrum center frequency and clutter power spectrum frequency spectrum width; according to the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width, and combining preset ground clutter and sea clutter threshold parameters, performing ground sea clutter type identification; calculating Doppler filter coefficients based on the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width; And carrying out Doppler filtering processing on the clutter data by using the Doppler filter coefficient so as to complete land and sea clutter suppression.
2. The method for identifying and suppressing ground-sea clutter based on clutter power spectrum estimation according to claim 1, wherein obtaining clutter data from radar echo data comprises: acquiring radar echo data, and performing pulse compression on the radar echo data to obtain pulse compressed data; And carrying out clutter threshold detection on the pulse compressed data, and extracting the clutter data.
3. The method for identifying and suppressing ground-sea clutter based on clutter power spectrum estimation according to claim 2, wherein the processing the clutter data to obtain the normalized clutter power spectrum density comprises: Estimating clutter power spectrum density according to clutter data, and carrying out average processing on the clutter power spectrum density to obtain average clutter power spectrum density; And setting a part of the average clutter power spectrum density lower than a set threshold value to be zero, and normalizing the average clutter power spectrum density subjected to zero treatment to obtain the normalized clutter power spectrum density.
4. The method for identifying and suppressing ground-sea clutter based on clutter power spectrum estimation according to claim 3, wherein fitting the normalized clutter power spectrum density to obtain a clutter power spectrum center frequency and a clutter power spectrum frequency spectrum width comprises: And fitting the normalized clutter power spectrum density by adopting a Gaussian power spectrum density function, and estimating to obtain the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width.
5. The method for identifying and suppressing ground-sea clutter based on clutter power spectrum estimation according to claim 4, wherein calculating doppler filter coefficients based on the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width comprises: constructing a clutter normalized autocorrelation function based on the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width, and constructing a clutter autocorrelation matrix according to the clutter normalized autocorrelation function; and calculating Doppler filter coefficients according to the clutter autocorrelation matrix.
6. The land and sea clutter recognition and suppression system based on clutter power spectrum estimation is characterized by comprising a clutter data acquisition module, a clutter data processing module, a fitting module, a recognition module, a coefficient calculation module and a suppression module; The clutter data acquisition module is used for acquiring clutter data from radar echo data; the clutter data processing module is used for processing the clutter data to obtain normalized clutter power spectrum density; the fitting module is used for fitting the normalized clutter power spectrum density to obtain clutter power spectrum center frequency and clutter power spectrum frequency spectrum width; the identification module is used for carrying out land and sea clutter type identification according to the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width and by combining with preset ground clutter and sea clutter threshold parameters; the coefficient calculation module is used for calculating Doppler filter coefficients based on the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width; The suppression module is used for performing Doppler filtering processing on the clutter data by using the Doppler filter coefficient so as to complete land and sea clutter suppression.
7. The system for ground-sea clutter identification and suppression based on clutter power spectrum estimation according to claim 6, wherein the clutter data acquisition module is specifically configured to: acquiring radar echo data, and performing pulse compression on the radar echo data to obtain pulse compressed data; And carrying out clutter threshold detection on the pulse compressed data, and extracting the clutter data.
8. The system for ground-sea clutter identification and suppression based on clutter power spectrum estimation according to claim 7, wherein the clutter data processing module is specifically configured to: Estimating clutter power spectrum density according to clutter data, and carrying out average processing on the clutter power spectrum density to obtain average clutter power spectrum density; And setting a part of the average clutter power spectrum density lower than a set threshold value to be zero, and normalizing the average clutter power spectrum density subjected to zero treatment to obtain the normalized clutter power spectrum density.
9. An electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing a clutter power spectrum estimation based method of land-sea clutter identification and suppression according to any of claims 1 to 5 when executing the computer program.
10. A computer readable storage medium, wherein a computer program is stored on the computer readable storage medium, the computer program when executed by a processor implementing a method for identifying and suppressing ground sea clutter based on clutter power spectrum estimation according to any of claims 1 to 5.

Description

Ground sea clutter identification and suppression method and equipment based on clutter power spectrum estimation Technical Field The invention relates to the technical field of radar clutter suppression, in particular to a method and equipment for identifying and suppressing ground-sea clutter based on clutter power spectrum estimation. Background The radar is inevitably affected by ground and sea clutter when working in an offshore environment, the ground and sea clutter are mixed in space, and the characteristics of the ground and sea clutter are interweaved in time domain and frequency domain, so that the detection of the radar on a moving target is seriously interfered, and the detection performance and tracking precision of the radar in a complex environment are obviously reduced. Therefore, how to effectively identify and inhibit the land and sea clutter becomes a key technical problem for improving the working efficiency of the radar in the area of the sea. In order to improve the detection capability of moving targets in the ground-sea clutter background, the clutter is usually suppressed by adopting a Doppler filtering processing mode such as classical moving target display (Moving Target Indication, MTI), moving target detection (Moving Target Detection, MTD) and Pulse Doppler (PD). The moving target display technology suppresses stationary or low-speed clutter by performing cancellation processing on echoes of a plurality of continuous pulses, and the moving target detection and pulse Doppler technology separates targets and clutter on different frequency bands by using a Doppler filter group. However, the above prior art has significant drawbacks. The conventional moving object display filter generates a fixed weight according to a binomial coefficient, but has a limited effect on clutter suppression with a wide spectrum width such as sea clutter because the binomial coefficient cannot adjust the position and width of the moving object display filter notch in the doppler frequency domain. However, when the average doppler velocity and the spectrum width of the clutter are unknown, the adaptive filtering design for forming depth suppression cannot be performed for the velocity interval actually occupied by the clutter, so that more clutter remains or the target signal is unnecessarily attenuated. In summary, the prior art lacks the capability of accurately estimating the characteristics of the ground-sea clutter on line, and is difficult to dynamically optimize the parameters of the Doppler filter according to the real-time clutter environment. Therefore, a new method capable of accurately estimating the power spectrum characteristics of the clutter and identifying the clutter type and accurately designing the filter coefficient according to the characteristics is needed to be provided so as to effectively inhibit the ground-sea clutter. Disclosure of Invention The invention aims to solve the technical problem of overcoming the defects of the prior art, and particularly provides a land-sea clutter recognition and suppression method and equipment based on clutter power spectrum estimation, wherein the method comprises the following steps: 1) In a first aspect, the present invention provides a method for identifying and suppressing land-sea clutter based on clutter power spectrum estimation, which specifically comprises the following technical scheme: Obtaining clutter data from radar echo data; processing the clutter data to obtain normalized clutter power spectrum density; fitting the normalized clutter power spectrum density to obtain clutter power spectrum center frequency and clutter power spectrum frequency spectrum width; according to the clutter power spectrum center frequency and the clutter power spectrum frequency spectrum width, and combining with preset ground clutter and sea clutter threshold parameters, performing ground sea clutter type identification; Calculating Doppler filter coefficients based on clutter power spectrum center frequency and clutter power spectrum frequency spectrum width; and (3) carrying out Doppler filtering processing on the clutter data by using Doppler filter coefficients so as to complete land and sea clutter suppression. The land-sea clutter identification and suppression method based on clutter power spectrum estimation has the following beneficial effects: The method directly overcomes the limitation that the notch position and width of the moving target display filter cannot be adjusted due to fixed binomial coefficients in the background art, and solves the problem that effective inhibition intervals cannot be formed due to unknown clutter parameters in moving target detection and pulse Doppler processing. Based on the accurate estimated clutter power spectrum center frequency and clutter power spectrum frequency spectrum width, and by combining with the preset threshold parameters of the ground clutter and the sea clutter, the system can adaptively d