PO-SBAS技术用于错朗玛冰川三维时序运动特征分析

Three-dimensional time series movement analysis of the Cuolangma glacier with PO-SBAS technique

山地冰川是全球气候变化的重要调节器和指示器,高时间分辨率、多维度的冰川流速监测能够对其运动造成的相关灾害进行精准的分析和预警.星载SAR技术是冰川运动监测的一种有效手段.本文采用了基于小基线集的像素偏移量技术,建立了联合升降轨偏移量的三维时序形变求解平差模型.利用2017年升降轨Sentinel-1A/B数据监测了喜马拉雅山中段北坡的错朗玛冰川三维时空运动特征.结果表明,错朗玛冰川在2017年4月13日至2017年12月9日时间段内,在东西向上最大流速为9.8 cm/day,南北方向上以20.5 cm/day的最大速度向北运动,垂直向上在坡度最陡峭处冰川最大速度为7 cm/day.结合地形与当地气温数据,发现该冰川运动整体上以地形因素主导,而外部气温环境会导致冰川流动发生局部特征变化.本文结果可为冰川运动引发的山地灾害研究提供参考.

Mountain glaciers are important regulators and indicators of global climate change. High-resolution and multi-dimensional glacier movement monitoring can provide accurate analysis and early warning to the related disasters. Space-borne SAR is an effective means to monitor glacier movement. In this paper, Pixel Offset-Small baseline subset is adopted to establish the adjustment model of the three-dimensional time-series deformation with ascending and descending datasets. Sentinel-1 A/B datasets are used to analyze the three-dimensional spatial and temporal motion characteristics of the Cuolangma glacier, which is located on the north slope of the middle section of the Himalayas. The results showed that during the period of 13 April 2017 to 9 December 2017, the maximum east, north and vertical velocities were 9.8 cm/day 20.5 cm/day and 7 cm/day respectively. Combined with the data of topography and local temperature, we found that the glacier movement is mainly dominated by topography, while the external temperature environment causes local characteristic change of glacier flow. The results can provide a reference for mountain disaster caused by glacier movement.