A dem-assisted insar demodulation and modulation processing method

Abstract

The invention discloses a DEM-assisted InSAR demodulation and modulation processing method, which fully considers the influence of flat ground effect and terrain phase on the encryption of interference fringes, and unwraps the fringes after reducing the fringe frequency to a minimum, simplifying the complex phase unwrapping problem . Compared with the prior art, the present invention regards the interferogram as an in-phase quadrature modulation signal modulated onto the high-frequency phase with the low-frequency phase as the Fourier coefficient, uses DEM to simulate the terrain phase with flat-earth effects, and constructs quadrature demodulation factor, transform the demodulation problem into the problem of solving complex Fourier coefficients, demodulate the low-frequency phase in the interferogram, and finally re-modulate the unwrapped interferogram to the high-frequency phase containing the terrain phase, which solves the problem of The phase unwrapping problem of conventional interferometry in mountainous areas with complex terrain can minimize the fringe frequency and improve the performance of phase unwrapping, thereby improving the inversion accuracy of DEM. This has important application value for improving the adaptability of InSAR to complex terrain.

Description

technical field [0001] The invention relates to the technical field of radar interferometry, in particular to a DEM-assisted InSAR demodulation modulation processing method. Background technique [0002] Synthetic aperture radar interferometry (Interferometric Synthetic Aperture Radar, InSAR) is to obtain and process the phase information of the complex interferogram by coherent processing of the main and auxiliary single-look complex images (SLC, Single Look Complex) with a certain viewing angle difference in the same area. , and then extract the surface elevation and elevation change information according to the phase elevation transformation geometric model. The biggest feature of this technology is that the processed data is phase information, and the phase is a function of wavelength and period. In order to more accurately remove phase errors and obtain high-precision elevation information, external DEM-assisted radar interferometry has received more and more attention...

AI Technical Summary

Problems solved by technology

[0005] In order to solve the above problems, the present invention provides a DEM-assisted InSAR demodulation and modulation processing method, which fully considers the influence of flat ground effect and terrain phase on the encryption of interference fringes, and then unwraps the fringes after reducing the fringe frequency to a minimum, so that the complex phase Simplifying the untangling problem

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