Processed line aeromagnetic data from the FISS 2016 surveys covering the Filchner and Halley Ice Shelves, and the English Coast (western Palmer Land), West Antarctica (2016/2017)

The dataset available here includes all channels from raw through to levelled and microlevelled products. Channel naming and processing follows SCAR/ADMAP2 data release protocols. channel description: Line:Flight Flight line and flight number. Format XYYY:ZZ X=L (line), T(Tie), P or S (legacy survey) Lat Lon Height_WGS84 Direct GPS navigation information, accurate to ~5 m. Date Time UTC time values MagR Raw magnetic data (nT) Tcorr Tip correction for aircraft systems (nT) RefField IGRF reference field (nT) MagRTC Mag corrected for Tips and reference field NOTE No compensation correction (nT) BCorr Base station correction with 30 min filter and after mean removal (nT) MagBRT Mag after base station correction (nT) - B=base corrected, T=tip corrected, R=regional corrected Acorr Heading correction - only applicable to some lines (nT) MagF Final mag field prior to levelling (nT) MagL Statistically levelled anomalies (nT) MagML Micro-levelled anomalies (nT) x y Polar Stereographic coordinates (m) FISS - 16/17 season Slessor: Opportunistic aeromagnetic data collected during an airborne radar survey. Flights with 2.5 km line spacing. Standard ADMAP2 processing flow, including IGRF and Tip tank corrections. However, due to the opportunistic nature of the survey no compensation calibration for aircraft motion was performed. Base station correction based on local base station filtered with 30 minute filter, after removal of mean base station value across the survey period. For levelling additional data from ADMAP2 compilation and ICEGRAV 2013 surveys was included to provide additional ties. These are coded as P or S lines, rather than L or T. Microleveling utilised gridded line data filtered with 10 km Butterworth How Pass, and cosine directional filter (with Azimuth 140, and degree 1). Filtered correction was sampled onto lines and low-pass filtered with 12 km Butterworth filter. Support Force processing notes: Opportunistic aeromagnetic data collected during an airborne radar survey. Flights with 2.5 km line spacing. Standard ADMAP2 processing flow, with IGRF correction. Tip corrections were not performed as these errors were restricted to areas outside the main survey grid, also due to the opportunistic nature of the survey no compensation calibration for aircraft motion was performed. Base station correction based on local base station filtered with 30 minute filter, after removal of mean base station value across the survey period. Microleveling utilised gridded line data filtered with 10 km Butterworth How Pass, and cosine directional filter (with Azimuth 52.5, and degree 0.75). Filtered correction was sampled onto lines and low-pass filtered with 12 km Butterworth filter. Baily Opportunistic aeromagnetic data collected during an airborne radar survey. Flights with 2.5 km line spacing. Standard ADMAP2 processing flow, including IGRF and Tip tank corrections. However, due to the opportunistic nature of the survey no compensation calibration for aircraft motion was performed. Base station correction based on local base station filtered with 30 minute filter, after removal of mean base station value across the survey period. Microleveling utilised gridded line data filtered with 10 km Butterworth How Pass, and cosine directional filter (with Azimuth 111, and degree 1). Filtered correction was sampled onto lines and low-pass filtered with 12 km Butterworth filter. Recovery Opportunistic aeromagnetic data collected during an airborne radar survey. Flights with 2.5 km to 5 km line spacing, and an array of oblique lines. Standard ADMAP2 processing flow, including IGRF and Tip tank corrections. However, due to the opportunistic nature of the survey no compensation calibration for aircraft motion was performed. Base station correction based on local base station filtered with 30 minute filter, after removal of mean base station value across the survey period. Microleveling utilised gridded line data filtered with 10 km Butterworth How Pass, and cosine directional filter (with Azimuth 33.6, and degree 1). Filtered correction was sampled onto lines and low-pass filtered with 12 km Butterworth filter.

本数据集包含从原始数据至经平差、微平差处理的全系列产品。所有测线命名与数据处理流程均遵循南极研究科学委员会（SCAR，Scientific Committee on Antarctic Research）/ADMAP2数据发布规范。

测线字段说明：
Line:Flight：飞行航线与航班编号，格式为XYYY:ZZ，其中X取值为L（航线）、T（联络测线）、P或S（传统测量）。
Lat Lon Height_WGS84：WGS84坐标系下的纬度、经度与高程，为直接GPS导航信息，定位精度约5米。
Date Time：UTC协调世界时时间戳。
MagR：原始磁测数据（单位：纳特（nT））。
Tcorr：飞行器系统姿态校正值（单位：nT）。
RefField：国际地磁参考场（IGRF，International Geomagnetic Reference Field）数值（单位：nT）。
MagRTC：经姿态校正与参考场校正后的磁测数据（注：未包含补偿校正，单位：nT）。
BCorr：经30分钟滤波并移除测期内基站均值后的基站校正值（单位：nT）。
MagBRT：经基站校正后的磁测数据（注：B代表基站校正、T代表姿态校正、R代表区域校正，单位：nT）。
Acorr：航向校正值，仅适用于部分航线（单位：nT）。
MagF：平差处理前的最终磁测场值（单位：nT）。
MagL：经统计平差后的磁异常值（单位：nT）。
MagML：经微平差后的磁异常值（单位：nT）。
x y：极球面投影坐标系坐标（单位：米）。

1. FISS - 16/17季（斯莱瑟（Slessor）区域）：为机载雷达测绘任务中采集的应急航空磁测数据，测线间距为2.5千米。采用标准ADMAP2处理流程，包含IGRF校正与姿态校正。但由于本测量为应急任务，未开展飞行器运动补偿校准。基站校正基于本地基站数据，经30分钟滤波并移除测期内基站均值后完成。平差处理时，引入ADMAP2整编数据与ICEGRAV 2013测量数据以提供额外联络测线，此类测线编码为P或S，而非L或T。微平差处理采用10千米巴特沃斯（Butterworth）高通滤波器与余弦方向滤波器（方位角140°，阶数1）对网格化航线数据进行滤波，将滤波后的校正值采样至航线数据后，再经12千米巴特沃斯低通滤波器处理。

2. Support Force：为机载雷达测绘任务中采集的应急航空磁测数据，测线间距为2.5千米。采用标准ADMAP2处理流程，包含IGRF校正。由于姿态校正误差主要分布在主测量网格以外区域，且本测量为应急任务，未开展飞行器运动补偿校准。基站校正基于本地基站数据，经30分钟滤波并移除测期内基站均值后完成。微平差处理采用10千米巴特沃斯高通滤波器与余弦方向滤波器（方位角52.5°，阶数0.75）对网格化航线数据进行滤波，将滤波后的校正值采样至航线数据后，再经12千米巴特沃斯低通滤波器处理。

3. Baily：为机载雷达测绘任务中采集的应急航空磁测数据，测线间距为2.5千米。采用标准ADMAP2处理流程，包含IGRF校正与姿态校正。但由于本测量为应急任务，未开展飞行器运动补偿校准。基站校正基于本地基站数据，经30分钟滤波并移除测期内基站均值后完成。微平差处理采用10千米巴特沃斯高通滤波器与余弦方向滤波器（方位角111°，阶数1）对网格化航线数据进行滤波，将滤波后的校正值采样至航线数据后，再经12千米巴特沃斯低通滤波器处理。

4. Recovery：为机载雷达测绘任务中采集的应急航空磁测数据，测线间距为2.5千米至5千米，包含多组斜交测线。采用标准ADMAP2处理流程，包含IGRF校正与姿态校正。但由于本测量为应急任务，未开展飞行器运动补偿校准。基站校正基于本地基站数据，经30分钟滤波并移除测期内基站均值后完成。微平差处理采用10千米巴特沃斯高通滤波器与余弦方向滤波器（方位角33.6°，阶数1）对网格化航线数据进行滤波，将滤波后的校正值采样至航线数据后，再经12千米巴特沃斯低通滤波器处理。