Abstract:
A British Antarctic Survey Twin Otter and survey team acquired 8,300 line-km of aerogeophysics data during the Austral summer of 1998/99. Gravity and radio-echo data were acquired simultaneously with the magnetic data at a compromise constant barometric height of 2,200 m, which provides a terrain clearance of 100 m over the highest peaks. Two separate surveys were conducted; one at 5 km line spacing (tie lines at 20 km) over and stretching beyond the southern extent of the Forrestal range (main survey), and one at 2 km line spacing (tie lines at 8 km) covering the Dufek Massif (detailed survey).
Ashtech Z12 dual frequency GPS receivers were used for survey navigation. Pseudorange data were supplied to a Picodas PNAV navigation interface computer, which was used to guide the pilot along the pre-planned survey lines. The actual flight path was recovered, using carrier-phase, continuous, kinematic GPS processing techniques. All pseudorange navigation data were recorded at 1 Hz on a Picodas PDAS 1000, PC-based data acquisition system.
We present here the processed bed elevation picks from airborne radar depth sounding collected using the "BAS-built" radar system (Corr and Popple, 1994; Fremand, Bodart et al., 2022), which used a 4 us linear frequency modulated pulse in addition to a standard short 0.25 us pulse
Data are provided as XYZ ASCII line data.
Keywords:
Aerogeophysics, Antarctica, Radar, Surface elevation
Corr, H. (2020). Processed bed elevation picks from airborne radar depth sounding across the Dufek Massif, Pensacola Mountains (1998/99 season) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/5e2cf315-9265-4605-8643-382f2557009b
| Use Constraints: | This data is covered by a UK Open Government Licence (http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/) Further by downloading this data the user acknowledges that they agree with the NERC data policy (http://www.nerc.ac.uk/research/sites/data/policy.asp), and the following conditions: 1. To cite the data in any publication as follows: Corr, H. (2020). Processed bed elevation picks from airborne radar depth sounding across the Dufek Massif, Pensacola Mountains (1998/99 season) (Version 1.0) [Data set]. UK Polar Data Centre, Natural Environment Research Council, UK Research & Innovation. https://doi.org/10.5285/5E2CF315-9265-4605-8643-382F2557009B 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. |
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| Creation Date: | 2020-06-29 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
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| Parameters: |
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| Personnel: | |
| Name | PDC BAS |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Mr Hugh Corr |
| Role(s) | Investigator |
| Organisation | British Antarctic Survey |
| Parent Dataset: | N/A |
| Reference: | Main references: Ferris, J.K., Johnson, A.C., Storey, B.C., 1998. Form and extent of the Dufek intrusion, Antarctica, from newly compiled aeromagnetic data. Earth and Planetary Science Letters, 154 185-202. https://doi.org/10.1016/S0012-821X(97)00165-9 Ferris, J.K., Storey, B.C., Vaughan, A.P.M., Kyle, P.R., Jones, P.C., 2003. The Dufek and Forrestal intrusions, Antarctica: a centre for Ferrar Large Igneous Province dike emplacement? Geophysical Research Letters 30 DOI: 10.1029/2002GL016719 Processing references: Lythe, M., Vaughan, D. G., and the BEDMAP Consortium. 2001. BEDMAP: a new ice thickness and subglacial topographic model of Antarctica, J. Geophys. Res., 106, 11335-11352. Fremand, A. C., Bodart, J. A., Jordan, T. A., Ferraccioli, F., Robinson, C., Corr, H. F., & Vaughan, D. G. (2022). British Antarctic Survey's Aerogeophysical Data: Releasing 25 Years of Airborne Gravity, Magnetic, and Radar Datasets over Antarctica. Earth System Science Data Discussions, 1-49. https://doi.org/10.5194/essd-14-3379-2022 Corr, H., Popple, M., 1994. Airborne radio echo sounding on the Evans flowline, Ronne ice shelf. In: Oerter, H. (Ed.), Filchner-Ronne Ice Shelf Programme 8. Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven, pp. 9-11. Fretwell, P., Pritchard, H.D., Vaughan, D.G., Bamber, J.L., Barrand, N.E., Bell, R., Bianchi, C., Bingham, R.G., Blankenship, D.D., Casassa, G., Catania, G., Callens, D., Conway, H., Cook, A.J., Corr, H.F.J., Damaske, D., Damm, V., Ferraccioli, F., Forsberg, R., Fujita, S., Gogineni, P., Griggs, J.A., Hindmarsh, R.C.A., Holmlund, P., Holt, J.W., Jacobel, R.W., Jenkins, A., Jokat, W., Jordan, T., King, E.C., Kohler, J., Krabill, W., Riger-Kusk, M., Langley, K.A., Leitchenkov, G., Leuschen, C., Luyendyk, B.P., Matsuoka, K., Nogi, Y., Nost, O.A., Popov, S.V., Rignot, E., Rippin, D.M., Riviera, A., Roberts, J., Ross, N., Siegert, M.J., Smith, A.M., Steinhage, D., Studinger, M., Sun, B., Tinto, B.K., Welch, B.C., Young, D.A., Xiangbin, C. & Zirizzotti, A., 2013. Bedmap2: improved ice bed, surface and thickness datasets for Antarctica, The Cryosphere, 7, 375-393, doi:310.5194/tc-5197-5375-2013. Fremand, A. C., Bodart, J. A., Jordan, T. A., Ferraccioli, F., Robinson, C., Corr, H. F. J., Peat, H. J., Bingham, R. G., and Vaughan, D. G.: British Antarctic Survey's aerogeophysical data: releasing 25 years of airborne gravity, magnetic, and radar datasets over Antarctica, Earth Syst. Sci. Data, 14, 3379-3410, https://doi.org/10.5194/essd-14-3379-2022, 2022. |
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| Quality: | No values are given for SurfPickLoc and bedPickLoc We do not have all the intermediate information for this legacy data |
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| Lineage: | Data available here includes bed and surface elevation sampled from a high resolution (100 m) grid of BEDMAP2 (Fretwell et al., 2013) data along DUFEK flight lines, with ice thickness subsequently derived. Basic information on data acquisition and processing is presented in Ferris et al. (2003). Channel description: Basic Channels Name Description Date UTC date (YYYY/MM/DD) Time UTC time (HH:MM:SS.SS) FlightID Sequential flight number and survey ID e.g. W12 Line_name Line Number e.g. LW200.1 Lon Longitude WGS 1984 Lat Latitude WGS 1984 x x projected meters* y y projected meters* Height_WGS1984 Aircraft altitude (meters) in WGS 1984 Radar segy_name Radar_segy file name TraceNum Radar segy trace number PriNum Raw radar time surfPickLoc Location down trace of surface pick bedPickLoc Location down trace of bed elevation pick surfElev Surface elevation bedElev Picked ice bed elevation tIce Ice thickness, derived from bedPickLoc and surfPickLoc. *Projected coordinates (x and y) are in Lambert conic conformal with two standard parallels defined as follows: Latitude of false origin: -80 Longitude of false origin: 80 Latitude of 1st standard parallel -83 Latitude of 2nd standard parallel -77 False easting 2000000 False northing 2000000 Positioning for the Dufek survey uses Ashtech Z12 dual frequency GPS recievers (Ferris et al, 2003). Positions are calculated for the phase centre of the aircraft antenna. All positions (Lat, lon and height) are referred to the WGS1984 ellipsoid. |
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| Temporal Coverage: | |
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| Start Date | 1999-01-20 |
| End Date | 1999-02-12 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -84.416 |
| Northernmost | -82.2399 |
| Longitude | |
| Westernmost | -64.3717 |
| Easternmost | -43.5947 |
| Altitude | |
| Min Altitude | N/A |
| Max Altitude | N/A |
| Depth | |
| Min Depth | N/A |
| Max Depth | N/A |
| Data Resolution: | |
| Latitude Resolution | N/A |
| Longitude Resolution | N/A |
| Horizontal Resolution Range | 30 meters - < 100 meters |
| Vertical Resolution | N/A |
| Vertical Resolution Range | N/A |
| Temporal Resolution | N/A |
| Temporal Resolution Range | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Dufek Massif |
| Location | Antarctica |
| Detailed Location | Pensacola Mountains |
| Sensor(s): |
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| Source(s): |
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| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 53 MB |
| Distribution Format | ASCII |
| Fees | N/A |
| Data Storage: | This dataset constains 1 ASCII XYZ file: - DUFEK_Rdar_ByFlight.XYZ ~53MB |