时序InSAR离散相干点相位解缠误差检查与校正方法研究
Detection and Correction of Phase Unwrappin g Errors in InSAR Time Series Analysis with Discrete Coherent Points
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摘要: 提出了一种基于三角形闭合环残差的离散相干点解缠相位误差检测与校正算法该算法能有效提高离散相干点解缠相位的精度 以沧州市沿海地区为实验区域利用2008 2010年18景ENVISAT ASAR数据进行InSAR时序分析对解缠相位跳变误差进行检测和校正并对比校正前后时序分析结果的精度 实验结果显示解缠相位一致性检查和误差校正可以有效改正解缠干涉图中的主要相位跳变误差与改正前相比1.离散点时序累积形变特征的时间连贯性更强减少了很多突跳 2.增加了有效相干点实验区内有效相干点个数由68 000个增加到186 400个3. 两个验证点累积形变量的RMS值分别降低了8．1mm和13．2mm证明了该方法的有效性Abstract: Due to temporal and spatial decorrelation and other noisethe inte ger－cycle jumps alwa ys appear in the unwrapped phase．It is well known that phase unwrapping errors re present one of the major limitations of Interferometric SARInSAR．A phase closure method is presented to detect and correct phase unwrapping errors for discrete coherent points in InSAR time series anal ysis．Its appli cation to ENVISAT Advanced Synthetic Aperture RadarASARdata over the coastal zone of Cangzhou Hebei Province showed a si gnificant improvement in the InSAR time series results with the number of valid coherent pixels increasing from 68 000to 186 400and the root mean square RMS decreasing from 13．1mm to 5．3mm and 17．5mm to 4．3mm for two deforming areas res pectivel y
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