Date (Creation)

2018-03-19

Date (Revision)

2018-03-19

Date (Publication)

2018-03-19

Date (released)

2018-03-19

Edition

None

Unique resource identifier

https://doi.org/10.5285/79e63097-f5dc-41ff-8ca5-36bc4f95a6ff

Codespace

doi

Unique resource identifier

GB/NERC/BAS/PDC/01073

Codespace

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

Other citation details

Please cite this item as: Becker, D., Jordan, T., Corr, H., & Robinson, C. (2018). Strapdown aerogravity survey across the Brunt Ice Shelf, 2017 (Version None) [Data set]. Polar Data Centre, Natural Environment Research Council, UK Research & Innovation, UK. https://doi.org/10.5285/79e63097-f5dc-41ff-8ca5-36bc4f95a6ff

Credit

No credit.

Status

Completed

Point of contact

Organisation name	Individual name	Electronic mail address	Role
Technische Universität Darmstadt	Becker, David		Author
British Antarctic Survey	Jordan, Tom		Author
British Antarctic Survey	Corr, Hugh		Author
British Antarctic Survey	Robinson, Carl		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 > Cryosphere > Glaciers/Ice Sheets > Glaciers
• EARTH SCIENCE > Cryosphere > Glaciers/Ice Sheets > Ice Sheets
• EARTH SCIENCE > Solid Earth > Geodetics/Gravity > Gravity

Theme

• Antarctica

• Brunt Ice Shelf

• Coats Land

• Geophysics

• Gravity

• Strapdown

Place

• Brunt Ice Shelf, Coats Land, East Antarctica Antarctica

GEMET - INSPIRE themes, version 1.0

• Elevation
• 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 both the data and literature reference in any publication as follows:

DATA REFERENCE

Becker, D., Jordan, T., Corr, H. & Robinson, C. "Strapdown aerogravity survey across the Brunt Ice Shelf, 2017" (2018) Polar Data Centre, Natural Environment Research Council, UK Research & Innovation, UK, doi:10.5285/79e63097-f5dc-41ff-8ca5-36bc4f95a6ff

LITERATURE REFERENCE

Jordan and Becker 2018 In prep.

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

No restrictions apply.

Unique resource identifier

url

Codespace

url

Association Type

Cross reference

Unique resource identifier

doi

Codespace

doi

Association Type

Cross reference

Unique resource identifier

url

Codespace

url

Association Type

dependency

Spatial representation type

Text, table

Language

English

Character set

UTF8

Topic category

• Climatology, meteorology, atmosphere
• Geoscientific information

Begin date

2017-01-09

End date

2017-01-14

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:

Gravity data during the Brunt 2017 survey were collected using a strapdown approach. This technique was first developed in the 1990's but advances in sensor design and data processing have only recently made this a viable method for field data collection. The strapdown gravity data was processed using an 18-state Kalman filter in conjunction with a Rauch-Tung-Striebel (RTS) smoother. Besides the 15 states of a typical IMU/GNSS integrating Kalman filter used for navigation (3-D position, velocity, attitude, and six inertial sensor biases), additional states are used to model the gravity disturbance with respect to GRS80 normal gravity. GPS coordinates were processed with a standard precise point positioning software package (Novatel Waypoint GrafNav 8.60), giving an average estimated positional error of 7.1 cm in the vertical and 3.1 cm in the horizontal. The GPS positional estimates were introduced as observations to the Kalman filter for the strapdown gravity calculation. The Kalman filter (and smoother) provides gravity estimates in a one-step evaluation, i.e. no additional low-pass filtering step is required. This method is sometimes referred to as the indirect method of strapdown gravimetry, because gravity is determined indirectly by introducing GNSS positions to the Kalman filter, rather than computing GNSS accelerations in a pre-processing step and manually combining them with the specific forces measured by the accelerometers in order to determine gravity.

In order to minimise thermal effects on the QA2000 accelerometers, the IMU was warmed up for at least two hours before each flight. However, a further thermal correction was applied to compensate reproducible thermal effects arising from internal sensor temperature changes along the flights. Details on the strapdown gravity data processing and the thermal calibration methods can be found in (Becker, 2016).

Data collection:

Data was collected using the BAS aerogeophysicaly equipped twin otter VP-FBL. Gravity data were recorded using an iMAR RQH-1003 inertial measurement unit (IMU), consisting of three Honeywell QA2000 accelerometers (mounted in mutually perpendicular directions), and three Honeywell GG1230 ring laser gyroscopes. Coincident GPS data were recorded with a NovAtel receiver.

Data quality:

The standard deviation of the strapdown gravity crossover errors for the 2017 season was 2.5 mGal, consistent with a Route Mean Square Error (RMSE) of 1.8 mGal. The estimated GPS positional errors were 7.1 cm in the vertical and 3.1 cm in the horizontal.

Resolution: The line spacing for the main survey area is 5km, with regional lines spaced ~18 km apart. The optimum along track resolution of the strapdown gravity system is approximately 100 seconds, consistent with a full wavelength spatial resolution for the 2017 Brunt survey of ~6 km (at an aircraft speed of approximately 60 m/s).

Metadata

File identifier

79e63097-f5dc-41ff-8ca5-36bc4f95a6ff XML

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Hierarchy level name

dataset

Date stamp

2018-03-19

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