TSP理论在二维相位解缠的应用

TSP theory in the application of two-dimensional phase unwrapping

干涉合成孔径雷达(interference synthetic aperture radar,InSAR)是根据两幅合成孔径雷达(syntheticaperture radar,SAR)图像对应像素点之间的绝对相位差所反映的距离差来获得目标高度的,但由干涉孔径雷达相位图像的相位差被限制在(-π,π]之间,因此模糊相位的展开是干涉合成孔径雷达信号处理的关键步骤之一。但由于噪声、欠采样等因素的影响,精确的相位展开变得非常困难,而路径跟踪法是一种重要的相位解缠方法,在路径跟踪法中,建立枝切线的长度越短解缠效果最好,因此如何建立枝切线十分重要,本文利用旅行商问题中求解最短路径的方法,提出一种利用改进的遗传算法建立连接正负残差点的最短枝切线,可以有效地避免在解缠过程中"孤岛现象"出现。

Interference synthetic aperture radar（InSAR） acquire target＇s altitude according to the difference in distance which derives from the absolute phase difference between the corresponding pixel points of two synthetic aperture radar（SAR） images.But the phase difference of interference aperture radars is limited in（-π,π],therefore the phase unwrapping is one of the key steps in InSAR signal processing.Due to the effect of noise and under sampled region,an accurate phase unwrapping has been quite difficult,path following is a major method in phase unwrapping.In the path following,the shorter the cut length is,the better the effet of phase unwrapping is,so how to establish a branch tangent is very important.An improved genetic algorithm is presented to establish the shortest branch tangent connecting the positive and negative residual error points by means of the traveling salesman problem（TSP） approach for solving the shortest path.The experiment result shows that the proposed algorithm can effectively avoid the unwrapping process of ＂isolated island phenomenon＂ to happen.