A comparison of sea-ice thickness measurements made using ship-mounted and airborne electromagnetic induction devices

Metadata record for data from ASAC Project 1342See the link below for public details on this project.---- Public Summary from Project ----This project involves field trialling of software written as part of ASAC project 1212 (2000-2001) to determine sea-ice thickness in real-time from ship-borne electromagnetic induction measurements. Computer simulation of ship- and helicopter-borne electromagnetic induction measurements over realistic sea-ice structures will also be performed in order to assess the suitability and cost-effectiveness of helicopter-mounted systems for future Antarctic sea-ice thickness measurements.Equipment used in this study were the IBEO PS100 infrared laser altimeter and the Geonics EM31 geophysical electromagnetic induction device.The fields in this dataset are:DAY is Julian dayTIME is in seconds after midnight (UTC).LASER is the laser altitude above the snow/ice (metres). A zero readingindicates no return (open water).PITCH is pitch of the system in degrees.ROLL is roll of the system in degrees.COND-A is analogue conductivity from the EM31 (not used).PHASE-A is analogue in-phase response from the EM31 (not used).COND is the estimated depth to seawater (metres) from the EM31-ICE processing module.PHASE is the EM31 in-phase response (expressed as parts per thousand of the primary field). A value of 9.99 indicates the magnetic field was too large to be recorded.SITELATITUDELONGITUDESNOW THICKNESSICE THICKNESSFREEBOARDa is the electrode spacing.R is the measured resistance.Rho is the apparent conductivity (not true conductivity) = 2 aR.CONDUCTIVITY = 1/Rho.

ASAC项目1342数据集元数据记录
有关该项目的公开详情，请参阅下方链接。
——项目公开摘要——
本项目针对ASAC 1212项目（2000-2001年）开发的软件开展现场试验，旨在通过船载电磁感应测量实时反演海冰厚度。同时，本项目还将针对真实海冰结构开展船载与直升机搭载电磁感应测量的计算机仿真，以评估直升机搭载系统在未来南极海冰厚度测量中的适用性与成本效益。
本研究使用的设备包括IBEO PS100红外激光高度计与Geonics EM31地球物理电磁感应仪。
本数据集包含以下字段：
DAY：儒略日（Julian day）
TIME：午夜（协调世界时，UTC）后的秒数
LASER：激光测得的雪/冰面上方高度（单位：米），读数为0表示无回波（对应开阔水域）
PITCH：系统俯仰角（单位：度）
ROLL：系统横滚角（单位：度）
COND-A：EM31输出的模拟电导率（未实际使用）
PHASE-A：EM31输出的模拟同相响应（未实际使用）
COND：通过EM31-ICE处理模块估算的海水埋深（单位：米）
PHASE：EM31同相响应值（以一次场的千分比表示），当取值为9.99时，表示磁场过强无法被记录
SITELATITUDE：站点纬度
LONGITUDE：站点经度
SNOW THICKNESS：雪层厚度
ICE THICKNESS：冰体厚度
FREEBOARD：干舷高度
a：电极间距
R：实测电阻值
Rho：视电导率（非真实电导率），计算公式为2 aR
CONDUCTIVITY：电导率，计算公式为1/Rho。