CN-122017745-A - Radar target detection method and system based on range gate noise normalization

CN122017745ACN 122017745 ACN122017745 ACN 122017745ACN-122017745-A

Abstract

The application relates to the technical field of radar target detection, in particular to a radar target detection method and system based on distance gate noise normalization. The radar target detection method comprises the steps of setting a coherent accumulation strategy according to basic scanning data, carrying out coherent accumulation processing on radar echo signals according to the coherent accumulation strategy, generating an initial velocity spectrum according to a processing result, setting a normalization instruction of the initial velocity spectrum, generating a velocity spectrum to be detected according to the normalization instruction, carrying out two-dimensional constant false alarm detection on the velocity spectrum to be detected, outputting real target points according to detection results, and carrying out noise normalization processing of a range-by-range gate, so that noise bottoms which are integrally lifted under the influence of strong clutter can be leveled, a shielded weak target signal is highlighted, unbalance of background noise is eliminated, the signal to noise ratio of a real target is relatively improved, the false alarm is effectively restrained, and meanwhile, the real target is not excessively restrained, so that the detection performance of the radar on the small target is improved.

Inventors

XU WENWEN
Quan shuanglong
CHEN ZHIYAO
ZHANG PING

Assignees

安徽耀峰雷达科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260413

Claims (8)

1. The radar target detection method based on the range gate noise normalization is characterized by comprising the following steps of: Setting a coherent accumulation strategy according to the basic scanning data; performing coherent accumulation processing on the radar echo signals according to a coherent accumulation strategy, and generating an initial velocity spectrum according to a processing result; Setting a normalization instruction of an initial velocity spectrum, and generating a velocity spectrum to be detected according to the normalization instruction; performing two-dimensional constant false alarm detection on a speed spectrum to be detected, and outputting a real target point trace according to a detection result; Wherein the initial velocity spectrum is two-dimensional signal data; The setting of the coherent accumulation strategy includes: generating a plurality of coherent cumulative functions; establishing a cumulative function library according to all coherent cumulative functions; Establishing various environmental signal characteristics; sequentially selecting objective functions from the cumulative function library; setting an adaptive scene of an objective function according to all the environmental signal characteristics; sequentially setting the adaptation scene of each coherent cumulative function; Establishing a target expected scene according to the basic scanning data; generating fitting values of a target expected scene and each adaptation scene, and setting a coherent accumulation function corresponding to the maximum value in all fitting values as an execution accumulation function; generating a coherent accumulation strategy according to the execution accumulation function; the normalization instruction for setting the initial velocity spectrum comprises the following steps: Establishing a noise reference library; The noise reference library comprises a plurality of noise reference sub-components: Generating a plurality of distance gates from the initial velocity spectrum; sequentially selecting target range gates from all range gates; Generating a background candidate set of the target distance gate according to the initial velocity spectrum; generating a priori background characteristic of the target distance gate; generating a normalization efficiency value of each noise reference sub-component to the target distance gate according to the background candidate set and the prior background characteristic; setting a noise reference sub-component corresponding to the maximum value in all normalized efficiency values as an execution reference sub-component of the target range gate; Setting execution reference sub-components of each range gate in sequence; and generating a normalization instruction according to all the execution reference sub-components.
2. The method for radar target detection based on range gate noise normalization of claim 1, wherein generating an initial velocity spectrum from the processing result comprises: Acquiring radar echo signals; Generating an initial two-dimensional matrix according to the radar echo signals; generating correction instructions and coherent accumulation instructions according to the coherent accumulation strategy; Preprocessing an initial two-dimensional matrix according to the correction instruction; And outputting an initial velocity spectrum according to the coherent accumulation instruction and the preprocessing result.
3. The method for radar target detection based on range gate noise normalization of claim 2, wherein the generating a set of background candidates for a target range gate comprises: generating a first Doppler data set according to the initial velocity spectrum; A plurality of subunits configured to generate a target range gate based on the first Doppler data set; Generating power values of the subunits; Generating a reject value of each subunit according to the total power value; presetting a rejection value threshold F1; If F1< fi, i=1, 2..n, generating a single reject instruction according to the i-th subunit of the target range gate; wherein fi is the rejection value of the ith subunit of the target distance gate, n is the number of subunits in the target distance gate; and generating a background candidate set of the target distance gate according to the output result of all the eliminating instructions.
4. A range gate noise normalization based radar target detection method according to claim 3 in which the generating a priori background characteristics of the target range gate comprises: Generating a second Doppler data set of the target range gate according to the basic scanning data; generating a priori background feature according to the second Doppler data set; The prior background features comprise a mean value, a median, a standard deviation, a variation coefficient and a quantile parameter.
5. The method for radar target detection based on range gate noise normalization of claim 4, wherein the generating a normalized efficiency value for each noise reference sub-component for a target range gate comprises: sequentially selecting target reference sub-components from a noise reference library; Generating a first-level processing value K1 of a target reference sub-component according to the prior background characteristic of the target distance gate; generating a secondary processing value K2 of the target reference sub-component according to the background candidate set of the target distance gate; Generating a normalized efficiency value d of the target reference sub-component, d=k1+k2.
6. A radar target detection system based on range gate noise normalization, employing the radar target detection method based on range gate noise normalization as claimed in any one of claims 1 to 5, comprising: a signal processing unit for setting a coherent accumulation strategy according to the basic scan data; The signal processing unit is also used for performing coherent accumulation processing on the radar echo signals according to a coherent accumulation strategy, and generating an initial velocity spectrum according to a processing result; The central control unit is used for setting a normalization instruction of the initial velocity spectrum and generating a velocity spectrum to be detected according to the normalization instruction; the central control unit is also used for carrying out two-dimensional constant false alarm detection on the velocity spectrum to be detected, and outputting a real target point trace according to the detection result; wherein the signal processing unit includes: the first processing module is used for generating a plurality of coherent cumulative functions; establishing a cumulative function library according to all coherent cumulative functions; Establishing various environmental signal characteristics; sequentially selecting objective functions from the cumulative function library; setting an adaptive scene of an objective function according to all the environmental signal characteristics; sequentially setting the adaptation scene of each coherent cumulative function; Establishing a target expected scene according to the basic scanning data; generating fitting values of a target expected scene and each adaptation scene, and setting a coherent accumulation function corresponding to the maximum value in all fitting values as an execution accumulation function; and generating a coherent accumulation strategy according to the execution accumulation function.
7. The range gate noise normalization based radar target detection system of claim 6, wherein the signal processing unit further comprises: the second processing module is used for acquiring radar echo signals; Generating an initial two-dimensional matrix according to the radar echo signals; generating correction instructions and coherent accumulation instructions according to the coherent accumulation strategy; Preprocessing an initial two-dimensional matrix according to the correction instruction; And outputting an initial velocity spectrum according to the coherent accumulation instruction and the preprocessing result.
8. The range gate noise normalization based radar target detection system of claim 7, wherein the central control unit comprises: the first control module is used for establishing a noise reference library; The noise reference library comprises a plurality of noise reference sub-components: Generating a plurality of distance gates from the initial velocity spectrum; sequentially selecting target range gates from all range gates; Generating a background candidate set of the target distance gate according to the initial velocity spectrum; generating a priori background characteristic of the target distance gate; generating a normalization efficiency value of each noise reference sub-component to the target distance gate according to the background candidate set and the prior background characteristic; setting a noise reference sub-component corresponding to the maximum value in all normalized efficiency values as an execution reference sub-component of the target range gate; Setting execution reference sub-components of each range gate in sequence; generating a normalization instruction according to all the execution reference components; Wherein generating a background candidate set of target distance gates comprises: generating a first Doppler data set according to the initial velocity spectrum; A plurality of subunits configured to generate a target range gate based on the first Doppler data set; Generating power values of the subunits; Generating a reject value of each subunit according to the total power value; presetting a rejection value threshold F1; If F1< fi, i=1, 2..n, generating a single reject instruction according to the i-th subunit of the target range gate; wherein fi is the rejection value of the ith subunit of the target distance gate, n is the number of subunits in the target distance gate; and generating a background candidate set of the target distance gate according to the output result of all the eliminating instructions.

Description

Radar target detection method and system based on range gate noise normalization Technical Field The application relates to the technical field of radar target detection, in particular to a radar target detection method and system based on distance gate noise normalization. Background Strong clutter (e.g., tall buildings) in urban environments can pose serious challenges when radar detects "low, small, slow" targets. Because the whole noise of the radar system and the suppression performance of the side lobe of the window function in the signal processing have theoretical limits, in the traditional two-dimensional constant false alarm detection, the energy of strong point clutter can leak to other Doppler channels, so that two main problems are caused: And the false alarm is diffused, namely a false target is formed on a plurality of speed channels by the strong clutter, and the false alarm rate of the whole machine is greatly improved. The shielding effect is that the strong clutter lifts the detection background noise (noise bottom) of the whole range gate where the strong clutter is located, so that the real tiny target signal near the range gate is submerged and cannot be effectively detected. The conventional clutter map or CFAR technology mainly solves the problem of clutter suppression between different distance gates, but is difficult to effectively solve the problem of shielding effect between units with different speeds near strong clutter caused by strong clutter sidelobe leakage. Disclosure of Invention The application aims to solve the technical problems, and provides a radar target detection method and system based on range gate noise normalization, which aim to inhibit the strong clutter shielding effect and improve the detection performance of a radar on a tiny target. In some embodiments of the application, through noise normalization processing of the range-by-range gate, the noise floor which is wholly lifted under the influence of strong clutter can be leveled, so that the shielded weak target signals are highlighted, the unbalance of background noise is eliminated, the signal to noise ratio of a real target is relatively improved, false alarms are effectively restrained, meanwhile, the real target is not excessively restrained, and the detection performance of the radar on the tiny target is improved. In some embodiments of the application, the noise reference of each range gate can adapt to the distribution of the local clutter and the target by dynamically selecting the noise reference in the normalization process, so that the pollution of the strong target to the background estimation is avoided, the statistical efficiency is maintained in a uniform area, and the detection performance of the radar in a non-uniform environment is improved. In some embodiments of the present application, a radar target detection method based on range gate noise normalization is provided, including: Setting a coherent accumulation strategy according to the basic scanning data; performing coherent accumulation processing on the radar echo signals according to a coherent accumulation strategy, and generating an initial velocity spectrum according to a processing result; Setting a normalization instruction of an initial velocity spectrum, and generating a velocity spectrum to be detected according to the normalization instruction; performing two-dimensional constant false alarm detection on a speed spectrum to be detected, and outputting a real target point trace according to a detection result; Wherein the initial velocity spectrum is two-dimensional signal data. In some embodiments of the application, the setting the coherent accumulation strategy includes: generating a plurality of coherent cumulative functions; establishing a cumulative function library according to all coherent cumulative functions; Establishing various environmental signal characteristics; sequentially selecting objective functions from the cumulative function library; setting an adaptive scene of an objective function according to all the environmental signal characteristics; sequentially setting the adaptation scene of each coherent cumulative function; Establishing a target expected scene according to the basic scanning data; generating fitting values of a target expected scene and each adaptation scene, and setting a coherent accumulation function corresponding to the maximum value in all fitting values as an execution accumulation function; and generating a coherent accumulation strategy according to the execution accumulation function. In some embodiments of the application, generating an initial velocity spectrum from the processing results includes: Acquiring radar echo signals; Generating an initial two-dimensional matrix according to the radar echo signals; generating correction instructions and coherent accumulation instructions according to the coherent accumulation strategy; Preprocessing an initial two-dimensional matri