CN-121634001-B - High dynamic range radar signal acquisition system and method

CN121634001BCN 121634001 BCN121634001 BCN 121634001BCN-121634001-B

Abstract

The invention discloses a high dynamic range radar signal acquisition system and method, and relates to the technical field of radars. The system comprises an intensity detection unit, a multi-channel acquisition unit, a channel selection unit and a signal processing unit, wherein the signal processing unit adopts a unique parallel processing architecture, the real-time feature extraction is carried out on the synchronized data stream on a first processing path to generate a window function selection instruction, and meanwhile, the accurate delay is carried out on the data stream on a second processing path, and the delay time is matched with the instruction generation time, so that the time alignment of the instruction and the data stream is realized. The system then determines an object window function based on the instruction and performs a windowing operation on the delayed data stream. The invention realizes double self-adaption of the channel and window functions, ensures that the full dynamic range signals from strong to weak can be optimally processed, and remarkably improves the signal acquisition quality and the radar detection performance.

Inventors

LI GUOLIANG
CHEN HAO
ZHU QIANWEI
CHEN GUOCHAO

Assignees

浙江华盛雷达股份有限公司

Dates

Publication Date: 20260512
Application Date: 20260204

Claims (10)

1. A high dynamic range radar signal acquisition system, the system comprising: the intensity detection unit is used for acquiring intensity information of radar echo signals; the multichannel acquisition unit is used for providing at least two acquisition channels with different signal adaptation ranges; the channel selection unit is used for selecting and conducting one acquisition channel from the multi-channel acquisition unit according to the intensity information; The signal processing unit is used for receiving the digital signals output by the selected acquisition channels and executing the following processing flow: Performing clock synchronization on the digital signals to obtain synchronous data streams; The synchronous data stream is processed through a parallel processing path, wherein on a first processing path, real-time feature extraction is carried out on the synchronous data stream to generate a window function selection instruction, and on a second processing path, the synchronous data stream is delayed by a preset time, wherein the preset time is configured to be matched with the time required for generating the window function selection instruction so as to realize the time alignment of the window function selection instruction and the delayed synchronous data stream; and determining an objective window function according to the window function selection instruction, and windowing the delayed synchronous data stream output by the second processing path and the objective window function.
2. The high dynamic range radar signal collection system of claim 1, wherein the intensity detection unit comprises: The signal conversion module is used for converting the radar echo signal into a current signal; And the current detection module is used for converting the current signal into the intensity information.
3. The high dynamic range radar signal acquisition system of claim 1, wherein the multi-channel acquisition unit comprises a first acquisition channel and a second acquisition channel, the first acquisition channel configured to have a first gain and a first range, the second acquisition channel configured to have a second gain and a second range, wherein the first gain is greater than the second gain, the first range is less than the second range; the channel selection unit is used for: And selecting the second acquisition channel when the intensity information is larger than or equal to a preset intensity threshold value, and selecting the first acquisition channel when the intensity information is smaller than the preset intensity threshold value.
4. The high dynamic range radar signal acquisition system of claim 1, wherein the signal processing unit comprises a clock domain synchronization module and a window function adaptive processing module that are logically implemented in hardware; The clock domain synchronization module is used for carrying out clock synchronization on the digital signals to obtain synchronous data streams; The window function self-adaptive processing module is used for realizing the parallel processing path, determining a target window function according to the window function selection instruction and performing windowing operation on the delayed synchronous data stream and the target window function; the signal processing unit also comprises an output buffer module which is used for carrying out output synchronization on the data subjected to windowing operation.
5. The high dynamic range radar signal collection system of claim 4, wherein the window function adaptive processing module comprises a feature analysis engine, a delay unit, a window function decision maker, a window function coefficient memory, and a window function applicator; The feature analysis engine is used for extracting real-time features of the synchronous data stream, and the window function decision maker is used for generating the window function selection instruction according to the extracted real-time features; The delay unit forms a second processing path for delaying the synchronous data stream; The window function applicator is connected to the output end of the delay unit, the output end of the window function decision device and the window function coefficient memory, and is used for reading the corresponding target window function coefficient from the window function coefficient memory according to the window function selection instruction, and multiplying the delayed synchronous data stream output by the second processing path with the target window function coefficient to complete the windowing operation.
6. The high dynamic range radar signal acquisition system of claim 5, wherein the delay unit is a first-in-first-out memory having a depth configured such that a delay time of data passing through the first-in-first-out memory is equal to the preset time.
7. The high dynamic range radar signal collection system of claim 1, wherein performing real-time feature extraction on the synchronous data stream to generate window function selection instructions comprises: extracting the signal intensity, the frequency spectrum width and the signal to noise ratio of the synchronous data stream; performing first-stage judgment according to the signal intensity; If the first-stage judgment shows that the signal strength is greater than a first threshold value, performing second-stage judgment according to the frequency spectrum width so as to select between a first-type window function for inhibiting frequency spectrum leakage and a second-type window function for ensuring amplitude measurement accuracy; And if the first-stage judgment shows that the signal strength is smaller than or equal to the first threshold value, performing third-stage judgment according to the signal-to-noise ratio so as to select among a third type window function for balancing performance, a fourth type window function for realizing high sidelobe suppression and a fifth type window function for realizing high frequency resolution.
8. The high dynamic range radar signal collection system of claim 7, wherein the first type of window function is a blackman window, the second type of window function is a flat top window, the third type of window function is a hanning window, the fourth type of window function is a blackman-harris window, and the fifth type of window function is a rectangular window.
9. The high dynamic range radar signal acquisition system of claim 1, wherein the channel select unit and the signal processing unit are integrated in a field programmable gate array.
10. A high dynamic range radar signal acquisition method, characterized in that it is applied to a high dynamic range radar signal acquisition system according to any one of claims 1 to 9, and that the method comprises: acquiring intensity information of radar echo signals; Selecting and conducting one acquisition channel from the multi-channel acquisition units according to the intensity information; analog-to-digital conversion is carried out on the radar echo signal through the selected acquisition channel, so that a digital signal is obtained; Performing clock synchronization on the digital signals to obtain synchronous data streams; The synchronous data stream is processed through a parallel processing path, wherein on a first processing path, real-time feature extraction is carried out on the synchronous data stream to generate a window function selection instruction, and on a second processing path, the synchronous data stream is delayed by a preset time, wherein the preset time is configured to be matched with the time required for generating the window function selection instruction so as to realize the time alignment of the window function selection instruction and the delayed synchronous data stream; and determining an objective window function according to the window function selection instruction, and windowing the delayed synchronous data stream output by the second processing path and the objective window function.

Description

High dynamic range radar signal acquisition system and method Technical Field The invention belongs to the technical field of radars, and particularly relates to a high dynamic range radar signal acquisition system and method based on multiple ADC and a self-adaptive window function. Background In the meteorological detection process, the intensity difference of echo signals generated by different complex weathers (such as heavy rain, hail, clear sky turbulence and the like) is extremely large, the dynamic range is often more than 100dB, and extremely high requirements are placed on the linear dynamic range of a receiving channel. The single ADC acquisition system widely adopted at present is difficult to accurately acquire strong echo and weak echo signals at the same time due to limited quantization range and signal-to-noise ratio. The method is characterized in that the strong echo is easy to cause front end saturation distortion to cause signal waveform distortion and spectrum leakage, and the weak echo is submerged by quantization noise due to the too low amplitude to cause signal-to-noise ratio reduction and effective information loss. In order to improve the dynamic range, a dual ADC architecture is adopted in the prior art, and a weak echo signal and a strong echo signal are respectively acquired through a high gain dual channel and a low gain dual channel. However, such systems still have the following problems in practical applications: (1) Transient effects are easy to generate during double-channel switching, signal continuity is destroyed, and extra errors are introduced; (2) The signal processing generally adopts a fixed window function, and cannot be adaptively adjusted according to the echo real-time characteristics, so that the spectrum resolution, the sidelobe suppression capability and the amplitude measurement precision are difficult to consider in the coexistence scene of strong echo signals and weak echo signals; (3) The lack of an efficient clock synchronization and data alignment mechanism further affects signal quality and system stability. The factors limit the detection precision and reliability of the high dynamic range weather radar under complex weather conditions. Therefore, a signal acquisition and processing method capable of realizing signal real-time feature extraction, adaptive window function selection and multi-level buffer synchronization based on a multi-ADC architecture is needed to systematically solve the data quality problem caused by signal mismatch, spectrum leakage and noise inundation in a high dynamic range environment. Disclosure of Invention Aiming at the defects in the prior art, the invention aims to provide a high dynamic range radar signal acquisition system and a high dynamic range radar signal acquisition method, so as to solve the problems that in the process of acquiring the high dynamic range radar signal, strong echo saturation distortion and weak echo are submerged in noise caused by overlarge signal intensity difference, and a fixed window function cannot be adaptively matched with spectrum leakage, resolution degradation and measurement error caused by different signal characteristics, thereby realizing accurate acquisition and high quality processing of signals in a full dynamic range. The invention solves the technical problems by adopting the following technical scheme that the high dynamic range radar signal acquisition system comprises: the intensity detection unit is used for acquiring intensity information of radar echo signals; the multichannel acquisition unit is used for providing at least two acquisition channels with different signal adaptation ranges; the channel selection unit is used for selecting and conducting one acquisition channel from the multi-channel acquisition unit according to the intensity information; The signal processing unit is used for receiving the digital signals output by the selected acquisition channels and executing the following processing flow: Performing clock synchronization on the digital signals to obtain synchronous data streams; The synchronous data stream is processed through a parallel processing path, wherein on a first processing path, real-time feature extraction is carried out on the synchronous data stream to generate a window function selection instruction, and on a second processing path, the synchronous data stream is delayed by a preset time, wherein the preset time is configured to be matched with the time required for generating the window function selection instruction so as to realize the time alignment of the window function selection instruction and the delayed synchronous data stream; and determining an objective window function according to the window function selection instruction, and windowing the delayed synchronous data stream output by the second processing path and the objective window function. Aiming at the defect that a single ADC system cannot give consideration to stro