采用JVC算法生成枝切线的干涉相位解缠方法

海面高程3维成像是随着天宫二号发射而实现的技术，相位解缠是3维成像高度计高程反演的关键步骤。为改进Goldstein枝切法，缩短干涉相位图中枝切线的总长度，提升相位解缠的精确性，该文提出一种基于JVC全局最优线性分配算法生成枝切线的相位解缠方法。首先找出干涉相位图中的所有残差点并计算每一对异号残差点之间的距离；通过对比每对残差点之间的距离和各自与最近边界的距离和，确定采用JVC算法放置枝切线还是在残差点与边界之间直接放置枝切线，使得平衡枝切线的总长度最短。通过对3维成像高度计海面高程仿真干涉相位图和Etna火山地区干涉图像进行解缠实验并与其他3种算法进行对比，表明该算法的解缠结果与真实相位值误差相对较小，而且能够有效避免“孤岛现象”的产生。

Interference Phase Unwrapping Method Using JVC Algorithm to Generate Branch Cuts

Three-dimensional imaging of sea surface altitude is a technology realized with the launch of Tiangong-2. Phase unwrapping is a key step in elevation inversion of three-dimensional radar imaging altimeter. In order to improve the branch cut algorithm proposed by Goldstein, shorten the total length of branch cuts in interferogram and advance the accuracy of phase unwrapping, a method that based on Jonker-Volgenant-Castanon (JVC) global optimal linear assignment algorithm to generate branch cuts is proposed in this paper. At first, all residual points in the interferogram are found out, and the distance between all opposite polarity pairs is calculated. Then, by comparing the distance between each pair of residual points and the distance sum between both of them and the nearest boundary, it is determined whether to place the branch cuts directly between the residual points and the boundaries or to use JVC algorithm. So, the shortest total length of the balanced branch cuts is obtained. The experiments of unwrapping are carried out by using the interferogram both of simulated three-dimensional imaging altimeter sea surface elevation and Etna volcano area. By comparison with the other three algorithms, it shows that the error between the unwrapping result of the proposed algorithm and the real phase value is relatively small. Also, it can void the “islanding phenomenon” effectively.