BGS Hosted Metadata
Processed line aeromagnetic data from the 2015/16 PolarGAP survey of the South Pole region.
The ESA PolarGap airborne gravity, lidar/radar and aeromagnetic survey was carried out in Antarctica in the field season 2015/16.
The purpose of the 2015/16 ESA PolarGAP airborne survey of the South Pole region was to fill the gap in satellite gravity coverage, enabling construction of accurate global geoid models. Additional radar flights over the Recovery Lakes for the Norwegian Polar Institute (NPI) were carried out as part of the same survey. In conjunction with the primary datasets aeromagnetic data was collected opportunistically, to provide new insights into the subglacial geology.
Data were collected using a caesium magnetometer system, and have been corrected to total field values following the approach laid out by the SCAR ADMAP working group ( http://admap.kopri.re.kr/ADMAP-2_SCR_27Aug13.pdf).
The aircraft used was the BAS aerogeophysicaly equipped twin otter VP-FBL.
Data are available as an ASCII table (.csv).
Simple
- Date (Creation)
- 2021-11-11
- Date (Revision)
- 2021-11-11
- Date (Publication)
- 2021-11-11
- Date (released)
- 2021-11-11
- Edition
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1
- Unique resource identifier
- https://doi.org/10.5285/4a6096e7-6350-416d-a2a1-6a24adaaf929
- Codespace
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doi
- Unique resource identifier
- GB/NERC/BAS/PDC/01584
- Codespace
- Other citation details
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Please cite this item as: None
- Credit
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No credit.
- Status
- Completed
- Point of contact
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Organisation name Individual name Electronic mail address Role British Antarctic Survey Jordan, Tom
Author British Antarctic Survey Robinson, Carl
Author Norvegian Polar Institute
Matsuoka, Kenichi
Author Technical University of Denmark
Olesen, Arne
Author Technical University of Denmark
Forsberg, Rene
Author British Antarctic Survey Ferraccioli, Fausto
Author NERC EDS UK Polar Data Centre Point of contact
- Maintenance and update frequency
- As needed
- Maintenance note
- Completed
- Theme
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Aerogeophysics
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Aeromagnetics
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Antarctica
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Magnetics
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South Pole
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geophysics
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- Place
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South Pole Antarctica
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Recovery Lakes Antarctica
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Thiel Mountains Antarctica
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GEMET - INSPIRE themes, version 1.0
- Access constraints
- Other restrictions
- Other constraints
- no limitations to public access
- Access constraints
- Other restrictions
- Other constraints
- no limitations
- Use constraints
- License
- Other constraints
- Open Government Licence v3.0
- Use constraints
- Other restrictions
- Other constraints
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This data is governed by the NERC Data Policy: https://www.ukri.org/who-we-are/nerc/our-policies-and-standards/nerc-data-policy/
- Use constraints
- Other restrictions
- Other constraints
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Further by downloading this data the user acknowledges that they agree with the NERC data policy (), and the following conditions:
1. To cite the data in any publication as follows:
2. The user recognizes the limitations of data. Use of the data is at the users' own risk, and there is no warranty as to the quality or accuracy of any data, or the fitness of the data for your intended use. The data are not necessarily fully quality assured and cannot be expected to be free from measurement uncertainty, systematic biases, or errors of interpretation or analysis, and may include inaccuracies in error margins quoted with the data.
- Use constraints
- Other restrictions
- Other constraints
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None
- Unique resource identifier
- doi
- Codespace
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doi
- Association Type
- Cross reference
- Unique resource identifier
- url
- Codespace
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url
- Association Type
- Cross reference
- Spatial representation type
- Text, table
- Language
- English
- Character set
- UTF8
- Topic category
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- Geoscientific information
))
- Begin date
- 2015-12-15
- End date
- 2016-01-20
- Supplemental Information
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It is recommended that careful attention be paid to the contents of any data, and that the author be contacted with any questions regarding appropriate use. If you find any errors or omissions, please report them to polardatacentre@bas.ac.uk.
- Title
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European Petroleum Survey Group (EPSG) Geodetic Parameter Registry
- Date (Publication)
- 2008-11-12
- Cited responsible party
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Organisation name Individual name Electronic mail address Role European Petroleum Survey Group
Publisher
- Unique resource identifier
- urn:ogc:def:crs:EPSG::3031
- Version
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6.18.3
Distributor
- Distributor contact
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Organisation name Individual name Electronic mail address Role NERC EDS UK Polar Data Centre Distributor
- Units of distribution
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bytes
- Transfer size
- 1
- OnLine resource
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Protocol Linkage Name WWW:LINK-1.0-http--link
https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=4a6096e7-6350-416d-a2a1-6a24adaaf929 Get Data
- Hierarchy level
- Dataset
- Statement
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Methodology:
The raw aeromagnetic data was initially corrected for DC offsets due to aircraft procedures, such as pumping fuel from so called 'tip tanks'. Most of these corrections were in turns, but logistical considerations meant such corrections on lines were unavoidable. Due to the unusual radial survey design normal compensation for aircraft dynamics was not possible. However, visual comparison between recorded fluxgate and total field data on the aircraft suggested most dynamic noise had a frequency of <15 seconds (~900m). The tip corrected data was therefore filtered with a 15 second low pass filter to remove dynamic noise prior to decimation from 10Hz to 1Hz to enhance the efficiency of data processing. The total field magnetic data was corrected for the core field using the 2015 IGRF, implemented in the Geosoft software package.
The base-station correction for diurnal variations was derived from multiple base-station observations. Base station data at the PolarGAP field camps (Thiel Mountains and FD83) was collected using total-field sensors, with additional fluxgate magnetometer data from the Polar Experiment Network for Geospace Upper atmosphere Investigations (PENGUIn) at South Pole and other remote field sites. All base station data was converted into total field values, and each station corrected to have a zero mean across the survey period. The theoretical base station value at the aircraft was calculated using an inverse distance weighting scheme to merge base station observations (Shenwary et al 2011). This incorporates the base station corrections from all available base stations weighted by their distance to the survey aircraft. This technique provided a smooth transition between different base stations, and ensures the most 'local' base station dominates the correction. As short wavelength diurnal variations observed at a base station are often not fully representative of those occurring at large distances from the base station, the base station corrections were filtered with either a 60 or 30 minute low-pass filter. The base station data is also provided for reference.
After base station correction preliminary levelling of the 30 minute base station corrected magnetic data was carried out. This included minimising internal crossovers and discrepancies with other surveys in the region. In general the preferred levelling method removed a 0, or 1st order trend revealed by errors at a number of intersections. Where residual line to line discrepancies remained, more complex spline levelling was applied. Further improvement of the dataset by more detailed levelling may be possible.
The aeromagnetic data set includes the following channels:
Line: Sequential survey flight number from P03 to P39: decimals denote line breaks.
Lon: Longitude DDD.DDDDDDDD
Lat: Latitude DD.DDDDDDDD
Elev: Elevation on the WGS1984 ellipsoid
Date: Date YYYY/MM/DD
Time: Time (UTC) HH:MM:SS.SS
MagR: Raw total field magnetic data (nT)
MagC: Pseudo-compensated total field magnetic data (nT)
TCorr: Tip correction (nT)
RefField: IGRF correction (nT)
MagRTC: Mag after IGRF: compensation and tip correction (nT)
Bcorr_60min: IDW base station correction with 60 minute mean filter (nT)
Bcorr_30min: IDW base station correction with 30 minute mean filter (nT)
MagB60RTC: Final mag after 60 min base station correction (nT)
MagB30RTC: Final mag after 30 min base station correction (nT)
MagL_B30RTC: Magnetic anomaly after preliminary levelling (nT)
The magnetic base station data set includes the following channels:
Line: PolarGAP flight number
TimeUTC: Time UTC (HH:MM:SS.SS)
UTCDate: Date (YYYY/MM/DD)
Longitude_decimal_degrees: Survey aircraft longitude (DDD.DDDDDDDDD)
Latitude_decimal_degrees: Survey aircraft Latitude (DD.DDDDDDDDD)
x: Polar stereographic projected aircraft x position (true scale -71) (m)
y: Polar stereographic projected airc...(23)
Data collection:
Data was collected using the BAS aerogeophysicaly equipped twin otter VP-FBL. Magnetic data was collected using wing tip mounted Scintrex CS-3 High Sensitivity Cs magnetometers. Only data from the magnetometer with the lowest noise characteristics is reported here. Data was recorded at 10 Hz on a PicoEnvirotec logging system. Additional base station information from total-field magnitomiters at field camps and fluxgate magnitomiters from the Polar Experiment Network for Geospace Upper atmosphere Investigations (PENGUIn) network were used.
Data quality:
After the basic processing presented here the standard deviation of the crossover errors was 52 nT, after preliminary levelling the crossover error was 25 nT.
Data resolution:
The radial design of the survey makes defining a specific resolution problematic. Line spacing at the survey edges was 90 km, reducing towards South Pole. The provided data is sampled at 1Hz, along track which equates to a ~60m along track sample spacing. The true usable resolution of this dataset is proportional to the depth to source, which averages to 2900 m across the survey.
Metadata
- File identifier
- 4a6096e7-6350-416d-a2a1-6a24adaaf929 XML
- Metadata language
- English
- Character set
- UTF8
- Hierarchy level
- Dataset
- Hierarchy level name
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dataset
- Date stamp
- 2021-11-11
- Metadata standard name
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ISO 19115 Geographic Information - Metadata
- Metadata standard version
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ISO 19115:2003(E)
- Metadata author
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Organisation name Individual name Electronic mail address Role NERC EDS UK Polar Data Centre Point of contact
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