ALOS-2 PALSAR-2的干涉相干性分析——以黄河上游地区为例

作为目前仅有的L波段星载SAR系统,PALSAR-2在国土资源调查和地质灾害监测方面有着广泛和独特的应用潜力。自其发射运行以来,它的数据质量成为用户们广泛关注的焦点。对于涉及雷达干涉测量的应用来说,干涉相干性是SAR数据最重要的质量评价指标之一。本文选取了覆盖黄河上游山区的PALSAR-2与PALSAR各一对影像,开展了干涉处理实验分析。本文提出采用相干分解技术,可以抑制几何去相干的影响,并从地物类型和地形坡度两个方面,分析比较它们的相干性分布差异,同时,给出了黄河上游地区的差分干涉初步结果。实验结果表明,在地形起伏较大的地区,相似观测模式获取的PALSAR-2数据的相干性通常优于PALSAR数据,干涉性能有显著的提升。同时,PALSAR-2差分干涉图在拉西瓦水电站果卜岸坡坡体上探测到了清晰的形变条纹,在滑坡体形变监测方面展现出巨大的应用潜力。

Interferometric Coherence Analysis of ALOS-2 PALSAR-2:In the Upstream Region of the Yellow River

As the only L band space-borne SAR system, PALSAR-2 is widely used in the field of land resources survey and geolog-ical disaster monitoring.Its data quality has become the focus of the user’ s attention.In the application of interferometry, coherence is the most important quality evaluation index of SAR data.In this paper, pairs of PALSAR-2 and PALSAR images in the upstream region of the Yellow River are selected to carry out the analysis of interference, and the difference of the interference performance of two generation sensors is compared.Considering the difference between spatial baselines, this paper uses the coherence decomposition technique to suppress the influence of geometric loss of coherence.From the aspects of land coverage type and terrain slope, the distri-bution difference of the coherence is analyzed, and the preliminary D-InSAR results in the test site are given.The result of the ex-periments show that, in the area where the terrain fluctuates, the coherence of PALSAR-2 data acquired by the similar observation mode is better than that of PALSAR.That is, the interference performance is significantly improved.Meantime, the deformation frin-ges on Guobu bank slope in front of Laxiwa Hydropower Station detected by PALSAR-2 shows good application potential in landslide monitoring.