Sorsdal Glacier GPS Data

The data archived here is the raw Global Navigation Satellite System (GNSS) recorded at Sorsdal Glacier, Princess Elizabeth Land, by two Trimble R9 receivers equipped with Trimble geodetic antennas housed inside SCIGN radomes and installed on the glacier surface.The two sites, labelled SO2 and SO8, were at S 68 degrees 42.42' E 78 degrees 06.06' (SO2) and at S 68 degrees 41.22' E 78 degrees 06.58' (SO8). SO2 was installed on 7th December 2015, SO8 on 24 January 2017. Both positions are handheld GPS quality initial positions; the GPS moved with the glacier after installation. The receiver at SO2 was named SOR1, the receiver at SO8 was named SOR2.The SO2 antenna was initially mounted on timber-framed tripods installed on the ice surface and secured with 30 kg concrete dead weights buried at shallow depths in the glacier surface and attached to the tripod with guy wires. The glacier surface consisted of blue ice with a thin cover of seasonal snow. This construction permitted significant movement of the antenna once melting had occured in December around the tripod frame. The problem was confirmed during a site revisiit on 24th December, and the antenna was re-mounted on a 4 m aluminium pole drilled 3 m into the ice on 17th January 2017, resulting in a suboptimal placement of the antenna / radome at a slightly lower elevation than the solar panel on the timber framing, but minimizing motion of the antenna.The SO8 installation copied the latter design, with the antenna / radome on an aluminium pole and the solar panel on a separate wooden tripod.Both installations are solar powered and may lose power during extended periods with no direct insolation. This occured during the 2016 winter from late May until late July, resulting in a data gap.The data is organized into zip files, SO2_archive_N and SO8_archive_N, N being a running index, accounting for downloads of data during site visits. Inside these, the raw data is organized into monthly directories named YYYYMM for year-month. As of September 2018, only SO2_archive_1 is available; more data will be added as it is retrieved from the fieldThe daily data files are named SORXYYYMMDD0000A.T02, where X = identifier of receiver (X = 1 for SO2, X = 2 for SO8), YYYY is the year, MM the onth and DD the day.In addition, for each station there are two processed GPS files, labelled AAS4342_GPS_SSXX_fixed_time_xyz_llh_sigma.dat and AAS4342_GPS_SSXX_fixed_time_vx_vy_vz_sigma.csv, where XX is the station label ('02' or '08').Each row of AAS4342_GPS_SSXX_fixed_time_xyz_llh_sigma.dat provides tab-separated data for one GPS position in the formatyear month day hour minute second ECEFx ECEFy ECEFz lat long height errorwith ECEFx, ECEFy and ECEFz being the (x,z,y) position of the antenna in the Earth-centre, Earth-fixed coordinate system, expressed in metres. lat long height are the equivalent decimal latitude, decimal longitude, height in metres relative to the WGS84 ellispoidal. error is an error estimte for position in mm. The raw GPS data was processed using kPPP in Gipsy-6.3 to produce this data set.Each row of the comma-separeted file AAS4342_GPS_SSXX_fixed_time_vx_vy_vz_sigma.csv provides a running mean velocity over a one-day period centred on the time stamp given, The data is in the formyear,month,day,hour,minute,second,ECEFvx,ECEFvy,ECEFvz,errorThe time stamp is self-explanatory, the ECEFvx, ECEFvy,ECEFvz values are velocity components in the Earth-centered, Earth-fixed coordinate system in metres per day, the error estimate is also in metres per day. Where there was no data spanning an exact day due to a data gap, the averaging inteval was extended or shrunk by up to 25 % to compute an average. Where that was not possible, a value of NaN was output.

本存档数据集为伊丽莎白公主地索斯达尔冰川（Sorsdal Glacier）处采集的原始全球导航卫星系统（Global Navigation Satellite System, GNSS）观测数据，由两台搭载Trimble大地测量天线的Trimble R9型接收机采集，天线安装于SCIGN天线罩内并固定于冰川表面。两个测站分别标记为SO2与SO8，坐标依次为南纬68°42.42′、东经78°06.06′（SO2）与南纬68°41.22′、东经78°06.58′（SO8）。SO2于2015年12月7日布设，SO8于2017年1月24日布设。两处初始位置均采用手持GPS获取的合格初始坐标，布设后接收机随冰川发生位移。SO2对应接收机编号为SOR1，SO8对应接收机编号为SOR2。SO2的天线最初安装于冰面搭建的木质三脚架上，通过埋设于冰川浅层的30kg混凝土配重块固定，并采用拉绳与三脚架相连。该冰川表面为蓝冰覆盖，仅薄覆季节性积雪。该布设方案在2015年12月融化发生后，导致天线出现显著位移。2016年12月24日的现场复查确认了该问题，随后于2017年1月17日将天线重新安装于一根打入冰面3m的4m铝合金杆上。此次调整虽导致天线/天线罩的安装高度略低于原木质支架上的太阳能板，但有效降低了天线的位移风险。SO8的布设沿用了调整后的方案：天线/天线罩安装于铝合金杆上，太阳能板则搭载于独立木质三脚架之上。两套设备均采用太阳能供电，在长期无直接日照的时段会出现供电中断。2016年冬季（5月下旬至7月下旬）即出现此类情况，导致数据间隙。本数据集以压缩包形式存档，命名格式为SO2_archive_N与SO8_archive_N，其中N为连续索引，对应历次现场访查时的数据下载批次。压缩包内部按年月（YYYYMM）创建月度目录存储原始数据。截至2018年9月，仅SO2_archive_1可供下载，后续将根据野外数据回收情况陆续补充上传。单日数据文件命名格式为SORXYYYMMDD0000A.T02，其中X为接收机标识符（SO2对应X=1，SO8对应X=2），YYYY为年份，MM为月份，DD为日期。此外，每个测站对应两份已处理的GPS数据文件，命名格式为AAS4342_GPS_SSXX_fixed_time_xyz_llh_sigma.dat与AAS4342_GPS_SSXX_fixed_time_vx_vy_vz_sigma.csv，其中XX为测站编号（'02'或'08'）。AAS4342_GPS_SSXX_fixed_time_xyz_llh_sigma.dat文件采用制表符分隔，每行对应一组GPS位置数据，格式为：年 月 日 时 分 秒 ECEFx ECEFy ECEFz 纬度 经度 高度 误差。其中ECEFx、ECEFy、ECEFz为天线在地球固连地心坐标系（Earth-centre, Earth-fixed, ECEF）下的坐标，单位为米；纬度、经度为对应的十进制度数，高度为相对于WGS84椭球面的高程，单位为米；误差为位置误差估计值，单位为毫米。原始GPS数据通过Gipsy-6.3软件中的kPPP模块处理得到该数据集。逗号分隔的AAS4342_GPS_SSXX_fixed_time_vx_vy_vz_sigma.csv文件每行对应以时间戳为中心的单日滑动平均速度数据，格式为：年,月,日,时,分,秒,ECEFvx,ECEFvy,ECEFvz,误差。时间戳格式无需额外说明；ECEFvx、ECEFvy、ECEFvz为地球固连地心坐标系下的速度分量，单位为米/天；误差估计值单位同样为米/天。若因数据缺失无法覆盖完整单日时段，则将平均窗口±25%范围内调整以计算平均值；若无法完成调整，则输出NaN值。

搜集汇总

背景与挑战

背景概述

该数据集包含2015年至2017年间在南极洲Sorsdal冰川上收集的原始和处理后GPS数据，用于监测冰川运动变化。数据来自两个站点，提供位置和速度测量，并包括误差估计，但存在冬季数据间隙。数据集公开可用，适用于气候和冰川研究。