SPICECAP/ICECAP II Instrument Measurements (LASER, MAGNETICS and POSITIONING)

These aerogeophysical data were collected as part of the ICECAP (International Collaborative Exploration of the Cryosphere through Airborne Profiling) collaboration in 2015/16 (ICP7). These data were in part funded by the US National Science Foundation (grant PLR-144390 to UTIG), ACE-CRC the G. Unger Vetlesen Foundation, and supported by the Australian Antarctic Division through project AAS-4346.This data collection represents georeferenced, time registered instrument measurements (L1B data) converted to SI units, and is of most interest to users who wish to reprocess the data. Users interested in geophysical observables should used the derived Level 2 dataset. The data format are space delimited ASCII files, following the formats used for UTIG/AAD/NASA's predecessor ICECAP/OIB project at NASA's NSIDC DAAC. Fields are described in the # delimited detailed header for each granule. POSITIONINGGPS provides the positioning (and timing) for all other data streamsSPUTG1B post processed 50 Hz positions; ASCII; used as source for interpolated position data in all Level 2 data streamsMAGNETICSMagnetics provides constraints on the depth to crystalline rock, and hence indicates the density of bathymetrySMGEO1B georeferenced total magnetic field data; 10 Hz ASCIIALTIMETRYRepeat track laser altimetry provides a history of thinning of outlet glaciersSLUTP1B georeferenced laser range data, no orientation corrections; 3.5 Hz ASCII

本航空地球物理数据集采集于2015/2016年度（ICP7项目），属于ICECAP（冰圈航空探测国际合作计划，International Collaborative Exploration of the Cryosphere through Airborne Profiling）协作项目的成果之一。本数据集部分经费由美国国家科学基金会（向德克萨斯大学海洋科学研究所(University of Texas Institute for Geophysics, UTIG)拨付的PLR-144390号资助项目）、ACE-CRC以及G·昂格尔·韦尔滕森基金会提供支持，并由澳大利亚南极局(Australian Antarctic Division)通过AAS-4346号项目提供协助。
本数据集包含已地理配准、时间同步的仪器测量数据（L1B级数据），已转换为国际单位制（SI units），主要面向希望对原始数据进行二次处理的用户。若需获取标准化地球物理观测数据，请使用衍生生成的L2级数据集。
本数据集采用空格分隔的ASCII文件格式，沿用了UTIG、澳大利亚南极局(Australian Antarctic Division)与NASA此前在NASA国家雪冰数据中心分布式活动档案库(National Snow and Ice Data Center Distributed Active Archive Center, NSIDC DAAC)开展的ICECAP/OIB前身项目所采用的格式。每个数据分块的详细字段说明均包含在以#号分隔的文件头注释中。
### 定位系统(POSITIONING)
GPS模块为所有其他数据流提供定位与授时服务。SPUTG1B为经过后处理的50Hz位置数据，采用ASCII格式存储，是所有L2级数据流中插值位置数据的核心源数据。
### 磁测数据(MAGNETICS)
磁测数据可约束结晶基底的埋深，进而间接反映海底地形的密度分布。SMGEO1B为已完成地理配准的总磁场数据，采样率为10Hz，采用ASCII格式存储。
### 测高数据(ALTIMETRY)
重复轨道激光测高数据可记录出口冰川(outlet glaciers)的变薄演化历史。SLUTP1B为已地理配准的激光测距数据，未进行姿态校正，采样率为3.5Hz，采用ASCII格式存储。