Interferometric phase filtering method

Abstract

The invention provides an interferometric phase filtering method. According to the technical schemes of the invention, the interferometric phase filtering method comprises the steps of frequency domain filtering and spatial domain filtering. According to the frequency domain filtering, an interferometric phase graph is converted to a complex field, so that a complex interferometric phase graph can be obtained; the complex interferometric phase graph is divided into square image blocks with overlapped areas; and frequency domain processing is performed on each image block, so that a frequency domain filtered complex interferometric phase graph can be obtained. According to the spatial domain filtering, the frequency domain filtered complex interferometric phase graph is subtracted from the complex interferometric phase graph, so that a residual complex interferometric phase graph can be obtained; the residual complex interferometric phase graph is filtered by using mean filtering, so that a spatial domain filtered residual complex interferometric phase graph can be obtained; the frequency domain filtered complex interferometric phase graph and the spatial domain filtered residual complex interferometric phase graph are added together, so that a filtered complex interferometric phase graph can be obtained, and phase selection is performed on the filtered complex interferometric phase graph, so that a filtered interferometric phase graph can be obtained. With the interferometric phase filtering method of the invention adopted, the detail information of interferometric phases can be reserved when noises are effectively filtered out.

Description

technical field [0001] The invention belongs to the intersecting technical field of remote sensing and signal processing, and in particular relates to an interference phase filtering method. Background technique [0002] The interferometric phase is obtained by conjugate multiplication of two SAR images and taking the phase of the multiplication result. Interferometric phase is an important physical quantity in SAR interferometry, and its quality will determine the accuracy of the final product—digital elevation model or terrain deformation. However, due to decorrelation factors, there is always serious space-varying noise in the interferometric phase. Space-variant noise will not only introduce residual points but also destroy the distribution of the interferometric phase, which increases the difficulty of subsequent phase unwrapping and eventually leads to a decrease in product accuracy, so it must be filtered out through the interferometric phase filtering process. [0...

AI Technical Summary

Problems solved by technology

Since it is impossible to completely separate the interferometric phase and noise, transform domain methods may result in filtered or underfiltered

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