融合梯度向量流条纹探测与图切法相位解缠

为解决GVF-Snake(gradient vector flow snake)条纹探测相位解缠时,内部条纹线探测偏离条纹边界的问题,提出了一种融合GVF-Snake条纹探测与马尔科夫随机场(Markov random field,MRF)图切法相位解缠方法.通过判断出条纹探测线不是真实条纹边界的情况,对该条纹探测线上一步探测条纹的内部块用MRF图切法进行分割解缠,按照相应解缠准则将两种解缠结果进行融合,形成含有边界跳跃点的粗解缠结果,并用高通滤波插值法消除粗解缠结果的边界孤立点的方法研究了矿区梯度较大地区的相位解缠.结果表明:以巨野矿区某工作面为实验区,用两景sentinel-1A的单视复数图像进行两轨法干涉处理的真实相位来验证算法的有效性.在面分析上,以自适应局部平滑相位评估(phase estimation using adaptive regulation based on local smoothing,PEARLS)为评价标准,将本文方法与最小费用流等5种相位解缠算法进行比较.对比结果显示,本文方法的平方根误差、平均绝对误差分别是±0.0791、±0.0090、±2.3173 rad.在线分析上,对只含有变形相位的绝对相位,提取各解缠绝对相位工作面走向线、倾向线的变形.以实际水准观测值为标准,本文方法的平方根误差、平均绝对误差、绝对值最大误差分别是±0.17748、±0.14107、±0.40529 cm.面分析中以PEARLS相位重构为基准,可见本文方法要优于其他常规的解缠方法;同理,线分析中以水准数据作为依据其各项指标亦为最优.

Fusion of GVF-Snake Fringe Detection and Phase Unwrapping of MRF Graph Cuts

In order to solve the problem that the detection of internal fringes deviates from the fringes boundary during the phase unwrapping of GVF Snake fringes detection, a phase unwrapping method combining GVF Snake fringes detection and Markov random field (MRF) graph cutting is proposed. By judging that the fringe detection line is not the real fringe boundary, the inner block of the one-step fringe detection line is segmented and unwrapped by MRF method, and the two unwrapped results are fused according to the corresponding unwrapped criteria to form the rough unwrapped results with boundary jump points. The method of eliminating the boundary isolated points of the rough unwrapped results by high pass filter interpolation is studied. Phase unwrapping in the area with large gradient in the mining area. The results show that the validity of the algorithm is verified by the real phase of two orbit interference processing with the single view complex image of sentinel-1a. In the area analysis, phase estimation using adaptive regulation based on local smoothing (pearls) is used as the evaluation standard to compare this method with five phase unwrapping algorithms such as minimum cost flow. The results show that the square root error and the mean absolute error of this method are ± 0.0791rad, ± 0.0090rad, ± 2.3173rad, respectively. In the on-line analysis, for the absolute phase with only deformation phase, the deformation values of the strike line and tendency line of each unwrapping absolute phase face are extracted. According to the actual level observation value, the square root error, average absolute error and the maximum error of absolute value of the method in this paper are ± 0.17748cm, ± 0.14107cm, ± 0.40529cm respectively. Based on the phase reconstruction of pearls in surface analysis, it can be seen that the unwrapping method in this paper is better than other conventional unwrapping methods; similarly, in line analysis, the indexes based on level data are also the best.