Date (Creation)

2021-11-11

Date (Revision)

2021-11-11

Date (Publication)

2021-11-11

Date (released)

2021-11-11

Edition

1

Unique resource identifier

https://doi.org/10.5285/32ac27a1-abe0-4f33-ba30-65a093511fb8

Codespace

doi

Unique resource identifier

GB/NERC/BAS/PDC/01583

Codespace

https://data.bas.ac.uk/

Other citation details

Please cite this item as: None

Credit

No credit.

Status

Completed

Point of contact

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		PDCServiceDesk@bas.ac.uk	Point of contact

Maintenance and update frequency

As needed

Maintenance note

Completed

Global Change Master Directory (GCMD) Science Keywords

• EARTH SCIENCE > Solid Earth > Geodetics/Gravity > Gravity
• EARTH SCIENCE > Solid Earth > Geodetics/Gravity

Theme

• Aerogeophysics

• Antarctica

• Gravity

• South Pole

• geophysics

Place

• South Pole Antarctica

• Recovery Lakes Antarctica

• Thiel Mountains Antarctica

GEMET - INSPIRE themes, version 1.0

• Geology

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

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

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:

https://doi.org/10.5270/esa-8ffoo3e - PolarGap: "Filling the GOCE polar gap in Antarctica and ASIRAS flight around South Pole"

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.

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Spatial representation type

Text, table

Language

English

Character set

UTF8

Topic category

• Geoscientific information

Begin date

2015-12-15

End date

2016-01-20

Supplemental Information

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

European Petroleum Survey Group (EPSG) Geodetic Parameter Registry

Date (Publication)

2008-11-12

Cited responsible party

Organisation name	Individual name	Electronic mail address	Role
European Petroleum Survey Group		EPSGadministrator@iogp.org	Publisher

Unique resource identifier

urn:ogc:def:crs:EPSG::3031

Version

6.18.3

Hierarchy level

Dataset

Statement

Methodology:

The airborne gravity measurements from the LCR gravimeter S-83 were corrected for aircraft dynamic movement using precise point positioning (ppp) GPS solutions following the methodology of Olesen et al 2002. Gravity from the iMAR RQH sensor was processed using a Kalman filtering approach to provide independent gravity estimates (Becker et al 2015). These independent estimates of the gravity field were combined using a Technical University of Denmark (DTU) in-house draping approach. This ensures that the long-wavelength, bias-stable LCR data are optimally merged with the more linear, but drifting, results of the iMAR RQH sensor.

The processing parameters for the LCR gravity data included a 130-150 sec 2nd order Butterworth along-track filtering, corresponding to a spacing on the ground of ca. 6 km. The flight elevations were generally low level (1200 ft AGL), but occasionally higher due to fog or low-level clouds; flight altitudes varied between 2.9 and 4.3 km.

The overall accuracy of the airborne processing was 2.2 mGal r.m.s., as inferred from 129-xover points, not taking into account the difference in heights at the cross-over points. This is a highly satisfactory result, given the rough conditions (field camps and temperatures down to -30degC), and the fact that the BAS Twin-Otter did not have an autopilot, which is usually a requirement for high-quality, bias-free aerogravity. No cross-over adjustment was performed on the data, so the data level of every single line is determined only by the gravimeter "apron" values, i.e. the stationary readings before or after flights. The gravity ties used to define absolute gravity values constraining the survey level were done with LCR land gravimeters G-784 (BAS) and G-867 (DTU), linked to earlier surveys and reference stations at McMurdo and Rothera, and adjusted in a least-squares process.

The aerogravity data set includes the following channels:

Fiducial: line_no*10000+running no

latitude_decimal_degrees: DD.DDDDD

longitude_decimal_degrees: DDD.DDDDD

ellipsoidal_height_m: Elevation referenced to WGS1984 ellipsoid (m)

gravity_disturbance_mGal: Gravity variations corrected to the WGS1984 ellipsoid (mGal)

gravity_anomaly_mGal: Free air gravity anomalies corrected to the GOCE R5 geoid (mGal)

Data collection:

Data was collected using the BAS aerogeophysicaly equipped twin otter VP-FBL. Two gravity systems were used: A ZLS-modified Lacoste and Romberg (LCR) gravimeter S-83 which is a stabilised platform type sensor, and a high grade inertial navigation unit, iMAR RQH-1003, provided by TU Darmstadt, which acted as a so-called strapdown gravity sensor. Data from both these instruments was merged to give an optimal final product.

Data quality:

The gravity anomalies showed crossover errors with 2.2 mGal r.m.s., as inferred from 129-intersections. No levelling or additional adjustment was carried out.

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 along track resolution is 6 km half-width based on the imposed filtering.

Metadata

File identifier

32ac27a1-abe0-4f33-ba30-65a093511fb8 XML

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Hierarchy level name

dataset

Date stamp

2021-11-11

Metadata standard name

ISO 19115 Geographic Information - Metadata

Metadata standard version

ISO 19115:2003(E)

Metadata author

Organisation name	Individual name	Electronic mail address	Role
NERC EDS UK Polar Data Centre		polardatacentre@bas.ac.uk	Point of contact