基于克里金插值和Chan-Vese模型边界探测的InSAR相位解缠方法

相位解缠是InSAR技术测量高程中的重要步骤，相位解缠的精度直接决定InSAR测量的精度。目前常用的相位解缠方法的解缠精度易受低相干区域的干涉噪声影响，针对在低相干区域相位解缠不准确的问题，提出了基于克里金插值和Chan-Vese模型的相位解缠方法。该方法在低相干区域进行克里金插值，重新计算低相干区域的干涉相位值，高相干区的干涉相位值不变，生成新干涉图，使用Chan-Vese法提取出新干涉图的干涉条纹边界，按照一定的方法计算出跃变数，达到相位解缠的目的。选取西藏自治区班戈县某矿山为试验区，采用C波段的Sentinel-1A合成孔径雷达数据对的干涉相位图为试验数据，对所提出的相位解缠方法与Goldstein枝切法等其他5种方法的相位解缠结果进行了对比分析。研究表明：所提方法具有一定的适用条件，在相干性较高的区域，该方法与其他方法的相位解缠结果差异很小；在低相干区域跨越不超过2个干涉条纹块的情况下，相比于其他方法，由所提方法相位解缠结果反演出的高程与SRTM1数字高程模型之间的差异在合理范围内，说明该方法仍然适用，而在低相干区跨越2个以上干涉条纹块的情况下，该方法不适用。

InSAR Phase Unwrapping Method Based on Kriging Interpolation and Chan-Vese Model Boundary Detection

Phase unwrapping is an important step in InSAR elevation measurement，the accuracy of phase unwrapping directly determines the accuracy of InSAR measurement.The unwrapping accuracy of commonly used phase unwrapping methods is susceptible to interferometric noise in low coherence region. In order to solve the problem that the result of phase unwrapping is inaccurate in low coherence region，a phase unwrapping method based on Kriging interpolation and Chan-Vese model is proposed.In this method，Kriging interpolation is performed in the low coherence region， and the interferometric phase values in the low coherence region are recalculated， the interferometric phase values in the high coherence region are unchanged， and a new interferogram is generated.The interferometric fringe boundary of the new interferogram is extracted by Chan-Vese method，and the jump coefficient is calculated according to certain methods， so as to achieve the purpose of phase unwrapping.A mining area in Bange County of Tibet was selected as the test area，the interference phase images which are produced by the pair of sentinel-1A synthetic aperture radar data (C-band) are used as experimental data，the phase unwrapping results of proposed unwrapping method are compared with those of other unwrapping method such as branch cut method proposed by Goldstein.The study results show that proposed method has some applicable conditions，there are little differences between the phase unwrapping results of this method and other methods in the high coherence region.In the condition of low conherence region spanning no more than two interferometric fringes，compared with other methods， the difference between the evaluation inverted from the unwrapping result of proposed method and SRTM1 digital elevation model is within a reasonable range， thus，the proposed method is still suitable.However，in the condition of low coherence region spanning more than two interferometric fringes， the proposed method is not suitable.