Raw GPS data from sites on the Totten Glacier, 2016-2019

This metadata record pertains to raw dual-frequency geodetic quality Global Positioning System (GPS) data from six sites deployed on the surface of the Totten Glacier between approximately late 2016 and early 2019. The data captures the three-dimensional motion/trajectory of the glacier over a period of approximately 2 years. The processed GPS data is covered in a separate metadata record.Site description:•    At each site, aluminium towers were erected on the glacier surface – these towers housed a GPS antenna connected to GPS receiver, batteries and solar panel. The approximate height of the GPS antenna was ~3 m above the snow surface at the time of deployment. The GPS receivers to logged data to all GPS satellites in view at a data rate of 1 observation every 15 seconds. •    The sites were revisited at the midpoint of the project during the 2017/18 austral summer field season. Given the expect large snow accumulation rate in the region of the deployment, the aluminium towers were extended to elevate the antenna ~3 m above the snow surface at that time.Data description:•    Raw GPS data files are provided as compressed (gzipped) files in the well-known Receiver Independent Exchange (RINEX) format (version 2.11). RINEX is ascii human readable after the files have been uncompressed.•    Each file is site specific and spans up to 24 hours of data (00:00:00 to 23:59:59 UTC) at 15 second sampling rate. •    File name format is: SSSSDDD0.YYo.gz where:o     SSSS = 4 character site code referring to the six sites, TG01 to TG06o    DDD = 3 character day of yearo    YY = 2 character yearo    o = RINEX observation fileo    gz = gzipped extension.•    Trimble NETR9 receivers and Trimble TRM57971.00 antennas were used. Receiver and antenna serial numbers and receiver firmware versions are provided in the header of each file.•    The observables in each file include L1 and L2 carrier phase observations, C1, C2 and P2 pseudorange observations and S1 and S2 signal to noise ratios. Each observation type is provided at 15 second epochs.Totten Glacier, East AntarcticaSite, Latitude, Longitude (GRS80)TG01 -67.3332728032 114.0188490931TG02 -67.2342527446 114.4687645468TG03 -67.4487717982 113.5865851863TG04 -67.4081289450 114.1060925834TG05 -67.3324797159 114.3542944081TG06 -67.5435154338 113.6953105206

本元数据记录对应2016年末至2019年初间，部署于东南极托滕冰川（Totten Glacier）表面的6个监测站点采集的双频大地测量级全球定位系统（GPS）原始数据。该数据集记录了该冰川约2年间的三维运动轨迹。经过预处理的GPS数据已在另一项元数据记录中予以说明。

站点布设说明：
• 每个站点均在冰川表面架设铝制塔架，塔架上搭载GPS天线、GPS接收机、蓄电池与太阳能板。部署初期，GPS天线距雪面高度约3米。GPS接收机对视野内所有可见GPS卫星进行数据采集，采样速率为每15秒获取1条观测值。
• 项目中期（2017/18年南极夏季野外作业季）对所有站点进行了复测。由于该区域积雪积累速率预期较高，本次复测中通过加高铝制塔架，将天线再次抬升至距雪面约3米的高度。

数据说明：
• 原始GPS数据文件以gzip压缩（后缀.gz）格式存储，采用通用的接收机独立交换格式（Receiver Independent Exchange, RINEX）2.11版本。文件解压后为ASCII格式，可直接人工读取。
• 每份文件对应单个站点，采集时长最长为24小时（协调世界时00:00:00至23:59:59），采样间隔为15秒。
• 文件名格式为：SSSSDDD0.YYo.gz，各字段含义如下：
- SSSS：4位字符的站点代码，对应6个监测站点TG01至TG06
- DDD：3位字符的年积日
- YY：2位字符的年份
- o：代表RINEX观测文件
- gz：gzip压缩文件扩展名
• 本次采集采用Trimble NETR9型接收机与Trimble TRM57971.00型天线。每份文件的文件头中均包含接收机与天线的序列号以及接收机固件版本信息。
• 每份文件包含的观测量包括：L1、L2载波相位观测值，C1、C2、P2伪距观测值，以及S1、S2信噪比。所有观测类型均以15秒为历元进行记录。

东南极托滕冰川站点坐标（GRS80坐标系）：
TG01：纬度-67.3332728032，经度114.0188490931
TG02：纬度-67.2342527446，经度114.4687645468
TG03：纬度-67.4487717982，经度113.5865851863
TG04：纬度-67.4081289450，经度114.1060925834
TG05：纬度-67.3324797159，经度114.3542944081
TG06：纬度-67.5435154338，经度113.6953105206