Multi-frequency data processing-based airborne D-InSar deformation detection method

Abstract

The present invention provides a multi-frequency data processing-based airborne D-InSar deformation detection method. According to the method, DEM (Digital Elevation Model) information is obtained through low-frequency echo data interference processing and inversion; the DEM information is adopted as reference rids for high-frequency echo BP imaging, so that a corresponding SAR image can be obtained; interferometric processing is performed on the SAR image, so that an interference phase containing terrain information and an interference phase containing terrain and terrain deformation information are obtained; and differential processing and inversion processing are performed on the two interference phases, so that corresponding terrain deformation variables can be obtained. With the method provided by the invention adopted, error introduced by the approximate calculation of a system can be controlled, and therefore, the detection precision of the system can be improved; contradiction between detection accuracy and data processing complexity of a traditional D-InSAR system can be alleviated; the information of high-frequency data can be obtained effectively; phase unwrapping difficulty can be reduced; the detection accuracy and stability of the system can be improved; de-grounding operation can be omitted; and flat-earth effect removal operation can be omitted; and an interference data processing flow can be simplified.

Description

technical field [0001] The present invention relates to the field of radar technology, in particular to an airborne platform, using low-frequency echo data to invert terrain DEM, using it as a BP imaging reference plane of high-frequency echo data to obtain corresponding SAR images, and obtaining them through differential interference processing High-precision terrain deformation detection method. Background technique [0002] Compared with spaceborne D-InSAR technology, the airborne D-InSAR system has the advantages of flexible orbit, short revisit period, and high detection accuracy, but at the same time, the airborne platform has problems such as low flight control capability and large track error. Therefore, how to improve The detection accuracy of the system has always been a research hotspot and difficulty. The traditional single-frequency D-InSAR system obtains terrain deformation information through steps such as SAR image registration, interference processing, de-l...

AI Technical Summary

Problems solved by technology

However, the flight altitude of the airborne platform is low. At this time, the instantaneous slant distance angle between the main and auxiliary antennas cannot be approximated to 0. If the slant distance difference is still approximated as the horizontal component of the baseline, a large system detection error will be introduced

At the same time, the track error of the airborne platform is relatively large, which brings certain difficulties to the selection of specific methods for the leveling operation.

[0004] In addition, the D-InSAR system still has the problem of the contradiction between the detection accuracy and the difficulty of data processing. The outstanding performance is that the phase unwrapping is difficult. Therefore, solving the above problems is the key to improving the detection accuracy and stability of the airborne D-InSAR system.

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