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:

BEDMAP 1 Consortia. (2020). Processed bed elevation picks from airborne radar depth sounding across East and West Antarctica (1966-1987) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/5C6447BC-7A49-4F0D-A782-3C542C2662AE

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.

Methodology:

RESPAC was the British Antarctic Survey radio-echo sounding database. It included data collected by BAS from 1966 to 1987.

A number of different radar systems were used to collect ice thickness and navigation data during these campaigns. All data in RESPAC was incorporated into both the BEDMAP1 (Lythe et al. 2001) and Bedmap2 (Fretwell et al. 2013) compilations. Here we provide basic channels containing information on flight line, data-point location, and ice thickness measurements which are described in the table below. It should be noted that early surveys (prior to 1987) did not use GPS positioning, but were located using a variety of methods such as celestial navigation, inertial avionics (INS), Doppler avionics and dead-reckoning. Furthermore, various processes of "refixing" were applied to most flightlines, with distributed navigational uncertainties through the flight and at fixed points during the flight to the map-position of known landmarks. In summary, all navigational data have large positional uncertainties of up to ~5 km (Drewry, 1983). It is assumed that all radar data processing is accurate and consistent; however, we do not consider it reasonable to make estimates of change in ice thickness from this dataset without considering the potential large navigation errors, varied collection systems and processing steps.

Data is available in a single file, split by the field season in which it was collected. For example, data from the 1966/67 field season will appear as L6667 (line) in the database.

Channel description:

Basic Channels Name Description

Current_record Linear time in seconds since 1st Jan 1950.

Season Season in which survey flights were undertaken

Lon Longitude WGS 1984

Lat Latitude WGS 1984

x x projected meters, coordinate system- Polar stereographic

y y projected meters, coordinate system- Polar stereographic

Height_WGS1984 Aircraft altitude (meters) in WGS 1984

Radar

tIce Ice thickness (m)

SurfElev Ice surface elevation (m)

BedElev Bed elevation (m)

*Projected coordinates (x and y) are in Polar Stereographic:

Latitude of natural origin: -71

Longitude of natural origin: 0

Scale factor at natural origin: 0.994

False easting 0

False northing 2072760.109