Processed line aeromagnetic data over Charcot Island, western Antarctic Peninsula (1996/97 season)

• Main Authors: Johnson, Ash, Ferris, Julie
• Format: Dataset
• Language: English
• Published: UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation 2020
• Subjects: "EARTH SCIENCE","SOLID EARTH","GEOMAGNETISM","MAGNETIC ANOMALIES"; "EARTH SCIENCE","CRYOSPHERE","GLACIERS/ICE SHEETS"; Aerogeophysics; Aeromagnetics; Antarctica; Antarctic; Antarctic Peninsula; Alexander Island; Charcot; Barton; Ferris; Charcot Island; Black Coast; Antarc*
• Online Access: https://dx.doi.org/10.5285/538212f3-5a76-4a89-8488-e061dbb53a03; https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01343

During the 1996-1997 Antarctic field season, an aeromagnetic survey was carried out by the BAS to the west of Alexander Island, designed to investigate the Charcot Island anomaly. The presented data was collected using wingtip mounted Caesium-vapour magnetometers. Magnetic effects due to aircraft motion were actively compensated using a triad of fluxgate magnetometers mounted in the tail of the aircraft. Data are provided as XYZ ASCII line data. : Charcot aeromagnetic data presented in Ferris et al. (2002). The dataset available here includes channels from raw through to levelled products, although not all typical corrections have been applied to the Black Coast dataset. Channel naming follows SCAR/ADMAP2 data release protocols. Magnetic data channels and processing flow: MagR- Raw magnetic total field intensity data (nT). MagC- Compensated, or low pass filtered magnetic data. 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. BCorr- Low pass filtered (60 minute) magnetic base station correction. MagBRTC- calculated as MagBRTC= MagRTC- Bcorr. ACorr- Additional correction applied to compensate for heading errors. MagF- Final mag value before levelling. MagL- Statistically levelled mag data. Basic channel description: Line name Line Number Flight ID Sequential flight number x x projected meters, Lambert conic conformal coordinate system * y y projected meters, Lambert conic conformal coordinate system * 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 Lambert conic conformal with two standard parallels defined as follows: Latitude of false origin: -64 Longitude of false origin: -70 Latitude of 1st standard parallel -76.4 Latitude of 2nd standard parallel -63.4 False easting 0 False northing 0 : Two wingtip-mounted Caesium-vapour magnetometers with a measurement accuracy of 0.01 nT were used. The magnetic effect of the aircraft were actively compensated using data from a triaxial fluxgate magnetometer mounted in the tail of the aircraft. Pseudorange GPS data were used for navigation but dual-frequency continuous kinematic data were recorded which, when post-processed, gave positional accuracies of better than 5 m. Lines were flown at 10 or 20 km intervals. The flight height was generally 1000 m above mean sea level, though occasional departures from this height were necessary to clear topography, and to avoid icing conditions. Processing of the data was carried out using the OASIS montaj Data Processing and Analysis system (Geosoft, 1997) which included data checking, merging navigation, continuation to a common elevation and removal of the 1995 IGRF (Barton, 1997) No values are given for MagC, TCorr, BCorr, MagBRTC, ACorr and SCorr. These channels are included for compatibility with ADMAP2 convention.