DOI: 10.5285/485e6b9b-d033-441f-8c98-b2d0efcb1d63
title: Processed line aeromagnetic data over the Pine Island Glacier basin (2004/05 season)

description: During the austral summer of 2004/05 a collaborative US/UK field campaign undertook a systematic geophysical survey of the entire Amundsen Sea embayment using comparable airborne survey systems mounted in Twin Otter aircraft. Here we present the portion of the survey covering the Pine Island Glacier basin led by British Antarctic Survey. Operating from a temporary field camp (PNE, S 77deg34' W 095deg56'); we collected ~ 35,000 km of airborne survey data. Our aircraft was equipped with dual-frequency carrier-phase GPS for navigation, radar altimeter for surface mapping, wing-tip magnetometers, gravity meter, and a new ice-sounding radar system (PASIN). We present here the processed line aeromagnetic data collected using scintrex cesium magnetometers mounted on the BAS aerogeophysically equiped Twin Otter. Data are provided as XYZ ASCII line data.
description: BBAS aeromagnetic dataset available here includes all channels from raw through to levelled, and microlevelled products. Channel naming follows SCAR/ADMAP2 data release protocols, although the order of processing steps differs from that outlined by ADMAP2 documentation. Note in the database split by line the sections are defined as follows L= main survey grid lines, T=main survey tie lines, P= Components of high resolution sub-grid. Magnetic data channels and processing flow: MagR- Raw magnetic total field intensity data (nT). MagC- Compensated, or low pass filtered magnetic data (nT). Adjustments to compensate for aircraft roll, pitch and yaw were applied (see Ferraccioli et al, 2007 for details). RefField- Geomagnetic reference field value for which the magnetic data has been compensated. IGRF model 2005 as implemented in Geosoft (nT). MagRTC- Compensated magnetic value adjusted for Tip tanks (where used) and geomagnetic reference field values. MagRTC= MagR- RefField (nT). BCorr- Low pass filtered (60 minute) magnetic base station correction. Data from three base stations were used for different portions of the survey (BCorr_AGAP_N, BCorr_AGAP_S, BCorr_AGAP_SP), along with a merged value between North and South base stations (BCorr_AGAP_NS). MagBRTC- calculated as MagBRTC= MagRTC- Bcorr (nT). ACorr- Additional correction applied to compensate for heading errors. MagF- Final mag value before levelling (nT). MagL- Statistically levelled mag data (nT). MagML- Microlevelled magnetic data following technique of (Ferraccioli et al., 1998) (nT). Note tie lines are not included in the microlevelled data channel Basic channel description: Line name Line Number Flight ID Sequential flight number x x projected meters* y y projected meters* Lon Longitude WGS 1984, Lat Latitude WGS 1984, Height_WGS1984 Aircraft altitude (meters) in WGS 1984, Date Date of flight in time format e.g. 2006/01/08 Time Time (UTC) of flight e.g. 23:52:42.0 *Projected coordinates (x and y) are in Polar Stereographic defined as follows: Latitude of natural origin: -71 Longitude of natural origin: 0 Scale factor at natural origin 0.994 False easting 0 False northing 2082760.109