DEM extraction method of vehicle-mounted SAR based on single control point information

Abstract

The invention discloses a DEM extraction method for a vehicle-mounted SAR based on single control point information. The DEM extraction method comprises the following steps of data preprocessing, interferometric phase calculation, phase unwrapping, distance correction, phase correction and elevation correction. According to the invention, DEM extraction of the vehicle-mounted SAR can be realized by only needing one piece of control point information; the field work can be effectively simplified; an error of the DEM extraction method based on the single control point information and influence of each interference parameter on the result are analyzed through a simulation test; the theoretical precision and realizability of the method are proved, huge influence of baseline parameters on DEM precision is defined, the precision of baseline length estimation is required to at least reach the millimeter level, it is verified that the DEM error obtained through the DEM extraction method basedon single control point information is only 0.30 m, and the method is effective and high in precision.

Description

technical field [0001] The invention relates to the technical field of DEM extraction, in particular to a DEM extraction method for vehicle-mounted SAR based on single control point information. Background technique [0002] The digital elevation model (DEM) describes the surface elevation information, and has a wide range of applications in the fields of surveying and mapping, hydrology, meteorology, geomorphology, geology, soil, engineering construction, communications, military and other national economic and national defense construction, as well as humanities and natural sciences; [0003] Synthetic Aperture Radar (SAR), as an active remote sensing sensor, is not affected by bad weather and has all-weather and all-weather earth observation capabilities. Its application in terrain surveying and mapping can effectively make up for the lack of optical means such as aviation / aerospace photogrammetry ; [0004] Synthetic Aperture Radar Interferometry (InSAR) technology was ...

AI Technical Summary

Problems solved by technology

[0005] In recent years, with the emergence of various radar wave systems, the miniaturization of SAR systems has gradually begun to be used and popularized. The carrying platforms will no longer be limited to traditional spaceborne platforms and large airborne platforms. Such platforms have begun to appear. For spaceborne SAR platforms, they have the advantage of wide imaging range, but the DEM accuracy obtained by InSAR processing is generally low due to factors such as orbit, decoherence, and low image resolution. High-precision application requirements, among which, vehicle-mounted SAR generally adopts the frequency-modulated continuous wave (FMCW) radar system, which is the mainstream of miniaturized synthetic aperture radar. Generate a large signal bandwidth and obtain high distance resolution. At the same time, the volume, cost and weight of the radar are greatly reduced. The research on the extraction of DEM by vehicle-mounted SAR interferometry can effectively solve the problem of low elevation accuracy and time-consuming problems of space-borne and airborne interferometry. Problems such as low resolution and heavy workload are of great significance. The technology for obtaining DEM for the interference processing of vehicle-mounted SAR data is somewhat different from the traditional interference processing of space-borne and manned airborne SAR, and there are still many problems that need to be solved urgently. Solved, the main problems include: (1) The vehicle-mounted SAR imaging height is low, and the main and auxiliary images are decoherent caused by large viewing angle changes; (2) In order to meet the real-time engineering requirements, the calibration of the vehicle-mounted SAR system needs to be repeated due to the variable structure. As a result, there is no problem of portability, etc. The solution of these problems requires the key technology of vehicle-mounted SAR to extract DEM. Therefore, the present invention proposes a method for extracting DEM of vehicle-mounted SAR based on single control point information to solve the problems in the prior art.

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