摘要
高分三号(GF-3)是我国第一颗民用C波段多模式SAR卫星,已在微小地表形变探测中展现出一定潜力。为验证GF-3提取冰川流动等大尺度位移的可靠性,本文选取5景条带模式GF-3影像,采用像素偏移追踪技术(POT)测量了喜马拉雅山脉热姆冰川2018年的流速场。结果显示热姆冰川粒雪盆区域流动速度最大,约为1 m/d,而在消融区流速最高到达30 cm/d,从冰舌上端至末端流速逐渐变缓。结合研究区气候和地形资料,分析发现外界温度变化是控制热姆冰川流动快慢的主要因素,同时局部地区流速受地形影响。选取与GF-3邻近时期拍摄的5景Sentinel-1A影像为数据源,利用POT进行热姆冰川同时期运动速度估计,发现两者估计的流速差值标准差为±1.58 cm/d,表明GF-3影像可作为冰川运动信息提取的一种重要数据源。
GF-3 is the first civil C-band SAR satellite in China with multiple observation modes, which has shown a potential in detecting small surface displacements. In order to verify the reliability of GF-3 in extracting large-scale ground displacement such as glacier flow, this paper investigated the surface velocity of Zemu Glacier, Himalayan, with five strip-mode GF-3 images acquired in 2018 using Pixel Offset Tracking (POT) technique. The results show that the maximum flow velocity is about 1 m/d in the snow basin of Zemu Glacier, while the maximum velocity in the ablation area is about 30 cm/d. The flow velocity gradually slows down from the top to the end of the ice tongue. By correlating the flow velocities with the climatic and topographic data, it is suggested that the changes in external temperature primarily control the flow speed of Zemu Glacier, although the topography may also influence the velocities in some areas. As a validation, we also used five Sentinel-1A images, acquired near to acquisition time of GF-3 images, to estimate the velocity of Zemu Glacier. The standard deviation of velocity difference between the measurements from GF-3 and Sentinle-1A is about ±1.58 cm/d, indicating that GF-3 images could be an important data source in glacier motion retrieval.
出处
《测绘科学技术》
2020年第2期78-87,共10页
Geomatics Science and Technology
基金
国家重点研发计划(2017YFB0502700),国家自然科学基金(41771402),国家自然科学基金青年科学基金(41804009),四川省科技支撑计划应用基础面上项目(20YYJC4292)。
