MIMO InSAR phase unwrapping method based on integer programming model

Abstract

The invention discloses an MIMO InSAR phase unwrapping method based on an integer programming model. The MIMO InSAR phase unwrapping method mainly comprises the steps of (1) constructing the integer programming model according to a corresponding relationship among a baseline ratio, a wavelength ratio and an elevation phase; (2) solving a minimum solution ki (i=1, 2, 3,..., N2) meeting the integerprogramming model by adopting a branch and bound method; (3) calculating an interferometric phase differential ambiguity resolution value d[phi]i at the corresponding pixel of the corresponding interferogram; and (4) performing integration on the interferometric phase differential ambiguity resolution values d[phi]i of all pixels in each interferogram by using a given phase unwrapping seed according to a certain path to obtain an unwrapping result [phi]i(x, y) of each interferogram. According to the invention, an objective function and constraint conditions thereof are constructed by analyzingrelationships between an interference phase and a baseline and between the interference phase and the frequency; an MIMO InSAR phase unwrapping problem is converted into a linear programming expression and optimal value solving problem, accurate and steady unwrapping of an MIMO InSAR interferometric phase is realized, and the elevation measurement performance and the surveying and mapping capability of the MIMO InSAR interferometric phase on complex terrains are improved.

Description

technical field [0001] The invention relates to a MIMO InSAR phase unwrapping method based on an integer programming model, belonging to the technical field of radar interferometry. Background technique [0002] Synthetic Aperture Radar (SAR) transmits broadband signals and uses synthetic aperture technology to project the three-dimensional information of space targets onto the azimuth-distance plane to obtain two-dimensional high-resolution images. The Synthetic Aperture Radar Interferometry (Interferometric Synthetic ApertureRadar, InSAR) technology developed on this basis can quickly obtain digital elevation models all day and all day long, and map and update topographic maps in areas seriously affected by clouds, rain and haze all year round. has important application value. [0003] The traditional single-baseline, single-frequency InSAR system is difficult to play a role in the surveying and mapping of complex terrain areas. Due to the limitation of system complexity ...

AI Technical Summary

Problems solved by technology

[0003] The traditional single-baseline, single-frequency InSAR system is difficult to play a role in the surveying and mapping of complex terrain areas. Due to the limitation of system complexity and cost factors, the number of independent observation channels that the existing multi-channel InSAR system can provide is also limited

[0004] In order to solve this problem, a MIMO InSAR phase unwrapping method based on an integer programming model is proposed. By using the MIMO InSAR phase unwrapping technology, the number of independent observation channels of the InSAR system can be greatly increased without increasing the operating frequency or observation array elements. , making full use of the high precision of high-frequency interferograms and the ease of solution of low-frequency interferograms, solving the problem of unwrapping spectrum aliasing and phase undersampling, improving its elevation measurement performance and mapping ability for complex terrain

Images