利用OICC-SBAS技术提取岗普冰川表面流速时空变化特征

Temporal-spatial characteristics of surface velocity of the Gangpu glacier based on OICC-SBAS technology

本文利用Sentinel-2数据,通过光学影像互相关技术(OICC),并借鉴小基线集(SBAS)思路,提取并分析了岗普冰川2015—2022年时序表面运动速度及时空变化特征。结果表明:岗普冰川表面流速存在明显的空间差异性,流速高值主要集中在上游的物质积累区,该区域形变特征复杂,年最高流速为82.5 m/a;冰川主体流速整体波动较小,位于40~50 m/a之间;时间特征上,冰川在研究时段内流速较为稳定,年际之间流速相差不大;利用东西向和南北向偏移量获取的最终偏移方向,与冰川实际流动方向相符,选取的稳定区域的偏移量误差仅占冰川最大流速的0.04%~0.7%,证实了冰川时序表面流速结果的可靠性。

In this paper,we use Sentinel-2 data to extract and analyze time-series surface motion velocities and spatial-temporal variability characteristics of Gangpu Glacier from 2015 to 2022 using optical imagery cross-correlation technology(OICC)and small baseline subset(SBAS).The results show that there are obvious spatial differences in the surface flow velocity of Gangpu Glacier,and the high values of flow velocity are mainly concentrated in the upstream material accumulation area,which has complex deformation characteristics,with the annual maximum flow velocity of 82.5 m/a.The overall fluctuation of the flow velocity in the main body of the glacier is small,mainly between 40 and 50 m/a.In terms of temporal characteristics,the flow velocity of Gangpu Glacier is relatively stable during the study period,with little difference in flow velocity between years.Meanwhile,the final offset directions obtained using the east-west and north-south offsets are consistent with the actual flow direction of the glacier,and the offset errors in the selected stabilization region only account for 0.04%to 0.7%of the maximum flow velocity of the glacier,which confirms the reliability of the results of the glacier time-series surface flow velocity.