Surface elevation of Bowdoin Glacier, Greenland in July 2015

Two sets of dual-frequency GPS (Leica Geosystems System 1200) were used to measure the surface elevation with a kinematic positioning mode. One GPS antenna was fixed on the bedrock at the eastern side of the glacier as a reference station. Another GPS antenna was mounted on a backpack to serve as a rover station. The survey was carried out along one longitudinal and three transverse profiles. Measurements were performed every seconds. Three-dimensional coordinates relative to the reference station were computed by post-processing the data with GPS analysis software (RTKLIB). The estimated error of the measurements is less than 5 cm.本研究采用两套徕卡测量系统（Leica Geosystems）System 1200型双频全球定位系统（Global Positioning System，GPS），以动态定位模式开展冰川表面高程测量。其中一套GPS天线固定于冰川东侧的基岩之上，作为基准站；另一套GPS天线搭载于背负式设备中，作为流动站。测量工作沿1条纵剖面与3条横剖面开展，测量频率为每秒一次。采用GPS分析软件（RTKLIB）对观测数据进行后处理，解算出相对于基准站的三维坐标。本次测量的估计误差小于5厘米。