CN-117031468-B - Synthetic aperture radar altimeter imaging processing method, system and storage medium

CN117031468BCN 117031468 BCN117031468 BCN 117031468BCN-117031468-B

Abstract

The invention relates to the technical field of synthetic aperture radar altimeter, and discloses a synthetic aperture radar altimeter imaging processing method, a system and a storage medium, which comprise the steps of obtaining and determining a plurality of distance compressed data of each target imaging point according to initial data of the synthetic aperture radar altimeter in imaging processing and a plurality of total delay correction data of each target imaging point; obtaining a target MASK image of each target imaging point based on a plurality of total delay correction data of each target imaging point, obtaining a target waveform image of each target imaging point based on the target MASK image of each target imaging point and a plurality of distance direction compression data, and generating target data of the synthetic aperture radar altimeter in the imaging process according to the waveform image. The invention improves the quality of the multi-view waveform on the premise of not increasing the operand, can realize the high-precision imaging processing of the synthetic aperture radar altimeter, and obtains the high-quality L1B data in the imaging processing of the synthetic aperture radar altimeter.

Inventors

XIAO FENG
KONG WEIYA
SUN HANWEI

Assignees

北京无线电测量研究所

Dates

Publication Date: 20260512
Application Date: 20230808

Claims (10)

1. A synthetic aperture radar altimeter imaging processing method, comprising: Obtaining and determining a plurality of distance compressed data of each target imaging point according to initial data of the synthetic aperture radar altimeter in the imaging process and a plurality of total delay correction data of each target imaging point; obtaining a target MASK image of each target imaging point based on a plurality of total delay correction data of each target imaging point, and obtaining a target waveform image of each target imaging point based on the target MASK image of each target imaging point and a plurality of distance direction compression data; And generating target data of the synthetic aperture radar altimeter in the imaging process according to the target waveform diagram of each target imaging point.
2. The method of imaging processing of a synthetic aperture radar altimeter according to claim 1, wherein the initial data includes first auxiliary data and a plurality of first burst data, and the step of obtaining a plurality of total delay correction data for each target imaging point based on the initial data of the synthetic aperture radar altimeter in the imaging processing includes: Performing linear interpolation processing on the first auxiliary data to obtain second auxiliary data, and determining a plurality of target imaging points from the second auxiliary data; Respectively and sequentially carrying out Doppler center correction and Doppler sharpening on each first burst data to obtain a plurality of second burst data, and determining the azimuth frequency energy position of each target burst data corresponding to each target imaging point from all the second burst data; and obtaining delay correction phases corresponding to the imaging points of each target according to the total delay correction of the energy positions of each azimuth frequency corresponding to the imaging points of each target, and multiplying the delay correction phases of the imaging points of each target with corresponding second burst data respectively to obtain a plurality of total delay correction data of the imaging points of each target.
3. The synthetic aperture radar altimeter imaging processing method of claim 1, wherein the step of determining a plurality of range-wise compressed data for each target imaging point based on a plurality of total delay correction data for each target imaging point includes: And respectively carrying out distance fast Fourier transform on each total delay correction data of any target imaging point to obtain a plurality of distance compressed data of the obtained target imaging point until a plurality of distance compressed data of each target imaging point are obtained.
4. The synthetic aperture radar altimeter imaging processing method of claim 2, wherein the step of obtaining a target MASK map for each target imaging point based on a plurality of total delay correction data for each target imaging point includes: Calculating each total delay correction corresponding to any target imaging point and the minimum total delay correction corresponding to the target imaging point respectively, generating a first MASK image of the target imaging point, generating a second MASK image of the target imaging point according to the missing position of each missing second burst data corresponding to the target imaging point, and multiplying the first MASK image and the second MASK image of the target imaging point to obtain a target MASK image of the target imaging point until the target MASK image of each target imaging point is obtained.
5. The synthetic aperture radar altimeter imaging processing method of claim 1, wherein the step of obtaining a target waveform map for each target imaging point based on the target MASK map and the plurality of range-wise compressed data for each target imaging point includes: According to the target MASK image of any target imaging point and a matrix corresponding to a plurality of distance compressed data, a first waveform image which corresponds to the target imaging point and comprises a plurality of waveforms is obtained, the waveforms in the first waveform image of the target imaging point are subjected to modular value and square processing, all the processed waveforms are accumulated, and a target waveform image of the target imaging point is obtained until the target waveform image of each target imaging point is obtained.
6. The synthetic aperture radar altimeter imaging processing method according to claim 2, wherein the step of generating target data of the synthetic aperture radar altimeter in the imaging processing from the target waveform map of each target imaging point includes: And generating the target data of the synthetic aperture radar altimeter in the imaging process according to the second auxiliary data and a target waveform diagram of each target imaging point.
7. The imaging processing system of the synthetic aperture radar altimeter is characterized by comprising a first processing module, a second processing module and a third processing module; The first processing module is used for obtaining and determining a plurality of distance compressed data of each target imaging point according to the initial data of the synthetic aperture radar altimeter in the imaging process and a plurality of total delay correction data of each target imaging point; The second processing module is used for obtaining a target MASK image of each target imaging point based on a plurality of total delay correction data of each target imaging point, and obtaining a target waveform image of each target imaging point based on the target MASK image of each target imaging point and a plurality of distance compressed data; The third processing module is used for generating target data of the synthetic aperture radar altimeter in the imaging process according to a target waveform diagram of each target imaging point.
8. The synthetic aperture radar altimeter imaging processing system of claim 7, wherein the initial data includes first assistance data and a plurality of first burst data, the first processing module being specifically configured to: Performing linear interpolation processing on the first auxiliary data to obtain second auxiliary data, and determining a plurality of target imaging points from the second auxiliary data; Respectively and sequentially carrying out Doppler center correction and Doppler sharpening on each first burst data to obtain a plurality of second burst data, and determining the azimuth frequency energy position of each target burst data corresponding to each target imaging point from all the second burst data; and obtaining delay correction phases corresponding to the imaging points of each target according to the total delay correction of the energy positions of each azimuth frequency corresponding to the imaging points of each target, and multiplying the delay correction phases of the imaging points of each target with corresponding second burst data respectively to obtain a plurality of total delay correction data of the imaging points of each target.
9. The synthetic aperture radar altimeter imaging processing system of claim 7, wherein the first processing module is further specifically configured to: And respectively carrying out distance fast Fourier transform on each total delay correction data of any target imaging point to obtain a plurality of distance compressed data of the obtained target imaging point until a plurality of distance compressed data of each target imaging point are obtained.
10. A storage medium having stored therein instructions which, when read by a computer, cause the computer to perform the synthetic aperture radar altimeter imaging processing method according to any one of claims 1 to 6.

Description

Synthetic aperture radar altimeter imaging processing method, system and storage medium Technical Field The invention relates to the technical field of synthetic aperture radar altimeters, in particular to a synthetic aperture radar altimeter imaging processing method, a synthetic aperture radar altimeter imaging processing system and a storage medium. Background Synthetic aperture radar altimeters introduce synthetic aperture technology based on conventional radar altimeters, and the data processing method is more complex than that of conventional radar altimeters. The synthetic aperture radar data processing (L1A- > L1B product production) generally comprises the following steps in the flow of 1) ground imaging point calculation, 2) forward track beam sharpening, 3) Stacking generation, 4) delay correction, 5) distance compression; 6) Masking, 7), multiview waveform generation. In step 1, the imaging point of the traditional synthetic aperture radar altimeter (SYNTHETIC APERTURE RADAR ALTIMETER, SARALTIMETER) adopts extrapolation to calculate the imaging point position, and the calculation accuracy is lower. In addition, the precision of the processing result generated by adopting a SARALTIMETER accurate processing mode and Stacking in the step 2 can meet the requirement, but the accurate processing time of the radar altimeter is large, and when the processing efficiency is generally considered, the step 2 generally adopts a traditional SARALTIMETER approximate processing mode, at this time, because the error accumulation in the step 2, the approximate error in the Stacking generation of the traditional SARALTIMETER is not negligible, the burst energy extraction precision is affected, and a certain error (extraction unit deviation) exists in the burst extraction, so that the problem of non-ideal precision exists in the quick production of the traditional L1B product of SARALTIMETER. Accordingly, there is a need to provide a solution to the above-mentioned problems. Disclosure of Invention The invention provides a synthetic aperture radar altimeter imaging processing method, a system and a storage medium for solving the problem of low product precision of L1B rapid production in traditional SAR ALTIMETER imaging. In a first aspect, the invention provides a synthetic aperture radar altimeter imaging processing method, which has the following technical scheme: Obtaining and determining a plurality of distance compressed data of each target imaging point according to initial data of the synthetic aperture radar altimeter in the imaging process and a plurality of total delay correction data of each target imaging point; obtaining a target MASK image of each target imaging point based on a plurality of total delay correction data of each target imaging point, and obtaining a target waveform image of each target imaging point based on the target MASK image of each target imaging point and a plurality of distance direction compression data; And generating target data of the synthetic aperture radar altimeter in the imaging process according to the target waveform diagram of each target imaging point. The synthetic aperture radar altimeter imaging processing method has the following beneficial effects: The method of the invention improves the multi-view waveform quality on the premise of not increasing the operand, and can realize the high-precision imaging processing of the synthetic aperture radar altimeter, thereby obtaining high-quality L1B data in the imaging processing of the synthetic aperture radar altimeter. Based on the scheme, the synthetic aperture radar altimeter imaging processing method can be improved as follows. In an alternative mode, the initial data comprises first auxiliary data and a plurality of first burst data, and the step of obtaining a plurality of total delay correction data of each target imaging point according to the initial data of the synthetic aperture radar altimeter in the imaging process comprises the following steps: Performing linear interpolation processing on the first auxiliary data to obtain second auxiliary data, and determining a plurality of target imaging points from the second auxiliary data; Respectively and sequentially carrying out Doppler center correction and Doppler sharpening on each first burst data to obtain a plurality of second burst data, and determining the azimuth frequency energy position of each target burst data corresponding to each target imaging point from all the second burst data; and obtaining delay correction phases corresponding to the imaging points of each target according to the total delay correction of the energy positions of each azimuth frequency corresponding to the imaging points of each target, and multiplying the delay correction phases of the imaging points of each target with corresponding second burst data respectively to obtain a plurality of total delay correction data of the imaging points of each target. In an alternative f