Phase filtering method and height measuring method of spaceborne interference imaging altimeter

Abstract

The invention discloses the phase filtering method and the height measuring method of a spaceborne interference imaging altimeter. The phase filtering method comprises the following steps of carryingout synthetic aperture imaging processing on the data of the two receiving channels of the spaceborne interference imaging altimeter to obtain two complex images, taking one of the images as a benchmark to register the two complex images, and calculating the coherence coefficient of the two registered images; successively calculating the geometric position, the observation angle, and the multi-view number of each pixel in the images; determining the azimuth filtering window size and the distance filter window size of each pixel, and determining the azimuth filtering interval and the distance filtering interval of each pixel; and carrying out conjugate multiplication on the two complex images, simultaneously removing a horizon phase, then, filtering each pixel in the azimuth filtering interval and the distance filtering interval, and finally acquiring the filtered interference phase. Based on the above phase filtering method, the invention also provides the height measuring method of the spaceborne interference imaging altimeter.

Description

technical field [0001] The invention relates to the technical field of radar signal processing, in particular to a phase filtering method and an altitude measurement method of a spaceborne interferometric imaging altimeter. Background technique [0002] The space-borne interferometric imaging altimeter is a device that uses short baseline and small-angle interferometric technology to measure the height of the sea surface and land. The space-borne interferometric imaging altimeter observes the earth's surface by deviating from the zenith, and simultaneously receives the radar echoes reflected by the earth's surface through two receiving antennas. wave, after processing, the phase difference of the observation images of the two antennas is obtained, also known as the interferometric phase, combined with the position of the phase center of the radar altimeter antenna to obtain the height of the earth’s surface (literature [1]: Y. Zhang, J. Jiang, H. Zhang, and D. Zhang, "Spaceb...

AI Technical Summary

Problems solved by technology

The traditional radar interferometric phase filtering method is designed for large-angle interference synthetic aperture radar. In the case of small-angle interference, there will be a problem of uneven altitude error along the cross-track direction, which will reduce the accuracy of altitude measurement.

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