Permafrost in Qinghai–Tibet Plateau (QTP) has been suffering from global warming in recent years, characterized by the deepening of the permafrost active layer. Seasonal changes in permafrost are usually reflected as ground surface deformation, which can be monitored by multi-temporal interferometric synthetic aperture radar (MT-InSAR) technology. Owing to the extreme environment in the QTP, there are few ground-based deformational observation data available, and records of permafrost monitoring by MT-InSAR with ground validation are limited. Here we present a study of surface deformation monitoring for permafrost with MT-InSAR technology validated by a large number of in-situ observations compared with the previous published results. In this study, a small baseline subset (SBAS) method was used with ENVISAT ASAR data in WuDaoLiang, QTP, to acquire the surface deformation and to analyze the corresponding characteristics. The results were first validated with 24 GNSS leveling observation points along the Qinghai–Tibet Railway, including numeric validation (e.g., statistics and KS test) between the InSAR derived deformation and the time-interpolated GNSS leveling values, and the variation trend of the two deformation sequences during a permafrost deformation period, at each observation point. Considering both the differences in magnitudes and trends, the deformation at 22 out of 24 points detected by InSAR corresponded well to the GNSS observation series over one year, which indicates the reliability of MT-InSAR for permafrost monitoring. After validation, the amplitudes and linear velocity of the InSAR deformation in this region were calculated and analyzed, together with selected points in different types of terrain. Generally, in the deformation map, most pixels show a trend of periodic and seasonal displacement, uplift in winter and subsidence in summer, with amplitudes of 3–10 mm in most regions. The deformation in mountain areas is less than that of flat lands in amplitude, and shows more randomness in periodic characteristics. Meanwhile, some points with obvious settlement have been detected, probably corresponding with permafrost degradation.

青藏高原多年冻土区（QTP）近年来受到全球变暖的影响，其特点是多年冻土活动层加深。多年冻土的季节性变化通常反映为地表变形，可以通过多时相干涉合成孔径雷达（MT-InSAR）技术进行监测。由于青藏高原的极端环境，可用的地基变形观测数据很少，经地面验证的MT-InSAR多年冻土监测记录有限。在这里，我们提出了一项使用 MT-InSAR 技术对永久冻土表面变形监测的研究，与之前发表的结果相比，该技术通过大量原位观测进行了验证。本研究采用小基线子集 (SBAS) 方法处理青藏高原五道梁的 ENVISAT ASAR 数据。获取表面变形并分析相应的特征。结果首先在青藏铁路沿线的24个GNSS水准观测点进行了验证，包括InSAR衍生变形与时间插值GNSS水准值之间的数值验证（例如统计和KS检验），以及两者的变化趋势在每个观测点的永久冻土变形期间的变形序列。综合考虑大小和趋势的差异，InSAR检测到的24个点中有22个点的变形与GNSS一年多的观测序列吻合较好，表明MT-InSAR在多年冻土监测中的可靠性。经验证，计算分析了该区域InSAR变形的幅值和线速度，以及不同类型地形中的选定点。一般来说，在变形图中，大部分像元呈现出周期性和季节性位移、冬季隆起、夏季沉降的趋势，大部分区域的幅度为3～10 mm。山区变形幅度小于平地变形，周期性特征更具有随机性。同时，也发现了一些有明显沉降的点，可能与多年冻土退化相对应。