多频率InSAR提取沼泽湿地DEM精度对比分析

Study on accuracy assessment of DEM in the marsh wetland using multi-frequency InSAR

选取3种波长的干涉SAR数据对提取沼泽湿地区域的DEM,并随机从1∶10 000地形图中选取111个点数据进行精度验证,最后对比分析了沼泽湿地植被对于不同SAR波长的干涉相干性差异。结果表明:L-band ALOS-1 PALSAR精细模式的HH单视复数数据与1∶10 000地形图数据吻合度较好,76.58%的高程值差异在3 m以内,其相干系数比C-band Sentinel-1A IW模式的VV单视复数数据和X-band TerraSAR HH单视复数数据要高;更适合利用雷达干涉测量技术提取沼泽湿地的DEM;不同湿地植被类型的相干系数有较大差异,岛状林和灌草结合的湿地植被分布区相干系数值较大,而浅水沼泽植被区和深水沼泽植被区相对较低。

In this paper,the interferometric SAR data of three wavelengths are selected to extract the DEM of the marsh wetland area,and 111 points of data are randomly selected from the 1∶10 000 topographic map for accuracy verification.Finally,the interference coherence difference of the swamp wetland vegetation for different SAR wavelengths is compared and analyzed.The results show that the ALOS-1 PALSAR images(L-band,HH)are in good agreement with the 1∶10 000 topographic map data,and the difference of elevation value of 76.58%is within 3 meters,and its coherence coefficient is also higher than that of Sentinel-1A images(C-band,VV,IW model)and TerraSAR images(X-band,HH).So,it’s more suitable to extract DEM of swamp wetland by radar interferometry.The coherence coefficient of different wetland vegetation types is also quite different.The distribution area of forest and shrub-grass vegetation has a larger coherence coefficient,while the shallow-water marsh vegetation area and deep-water marsh vegetation area are relatively low.