Abstract:
Magnitude and x and y components of surface speed on the Larsen C ice shelf, Antarctica. The datasets are annual means from 2015 to 2022 at a horizontal resolution of 100 m. The data are based on feature tracking of Sentinel 1 Synthetic Aperture Radar (SAR) satellite data. The velocities were created to support a NERC-funded project investigating ice-shelf rift propagation, by Prof. Adrian Luckman.
NERC standard grant NE/T008016/1.
Keywords:
Antarctica, Larsen C, feature-tracking, ice shelf, velocity
Luckman, A., & Bevan, S. (2024). Annual georeferenced rasters of ice-surface velocity for the Larsen C ice shelf, Antarctica, between 2015 and 2022 (Version 1.0) [Data set]. NERC EDS UK Polar Data Centre. https://doi.org/10.5285/4259989a-8485-4066-a2e8-9678d63056b4
| Access Constraints: | No restrictions apply. |
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| Use Constraints: | Data supplied under Open Government Licence v3.0 http://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/. |
| Creation Date: | 2024-12-09 |
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| Dataset Progress: | Complete |
| Dataset Language: | English |
| ISO Topic Categories: |
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| Parameters: |
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| Personnel: | |
| Name | UK Polar Data Centre |
| Role(s) | Metadata Author |
| Organisation | British Antarctic Survey |
| Name | Adrian Luckman |
| Role(s) | Investigator |
| Organisation | Swansea University |
| Name | Suzanne Bevan |
| Role(s) | Technical Contact |
| Organisation | Swansea University |
| Parent Dataset: | N/A |
| Reference: | Liu, H., Jezek, K.C., Li, L., Zhao, Z., 2015. Radarsat Antarctic Mapping Project Digital Elevation Model, Version 2. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/8JKNEW6BFRVD. Howard, S. L. and Padman, L.: CATS2008: Circum-Antarctic Tidal Simulation version 2008, U. S. Antarctic Program (USAP) Data Center, https://doi.org/10.15784/601235, 2015. |
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| Quality: | The name of each annual Geotiff contains the number of feature-tracked image pairs contributing to the measurement. Images which make up a pair may have either a 6-day (between Sentinel 1A and Sentinel 1B) or a 12-day time separation (Sentinel 1A only). Image-pairs with a 12-day separation have poorer velocity retrieval owing to increased surface decorrelation. Therefore, quality is best for the 2017, 2018, 2019 and 2020 means when both Sentinel 1A and Sentinel 1B were both in operation. | |
| Lineage: | Speeds were measured by feature-tracking Sentinel-1A and 1B SAR images with a temporal separation of 6 or 12 days. Displacements in SAR image geometry were filtered twice: first by a signal to noise ratio based on the cross-correlation of image patches, and then according to deviation from the mean displacement within a neighbourhood. The filtered displacements were converted from the SAR geometry to ground-range geometry, and the results geocoded using the RAMP Digital Elevation Model (Liu et al., 2015). The vertical tidal signal was removed using the Circum-Antarctic Tidal Simulation version 2008 (CATS:2008) model (Howard and Padman, 2015). Individual maps of velocity (between 30 and 122 per year) were averaged to create annual means. | |
| Temporal Coverage: | |
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| Start Date | 2015-01-01 |
| End Date | 2022-12-31 |
| Spatial Coverage: | |
| Latitude | |
| Southernmost | -69.824 |
| Northernmost | -65.564 |
| Longitude | |
| Westernmost | -64.592 |
| Easternmost | -61.152 |
| 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 | 100 meters - < 250 meters |
| Vertical Resolution | N/A |
| Vertical Resolution Range | N/A |
| Temporal Resolution | N/A |
| Temporal Resolution Range | N/A |
| Location: | |
| Location | Antarctica |
| Detailed Location | Larsen C ice shelf |
| Sensor(s): |
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| Source(s): |
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| Data Collection: | The Sentinel data were supplied by ESA and processed using Gamma Remote Sensing software. |
| Distribution: | |
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| Distribution Media | Online Internet (HTTP) |
| Distribution Size | 902 MB |
| Distribution Format | TIFF |
| Fees | N/A |
| Data Storage: | There are 24 georeferenced Geotiffs, an x, a y and a magnitude of speed for each year 2015-2022. Each file is ~ 35 MB. Geotiffs are named as follows: mean_mosaic.year.6or12-day.1to6-pairs.tracks-all.mosaics-np.track_filt_detide.mean.comp Where year is the year, np is the number of feature-tracked pairs contributing to the mean, and comp is x, y or mag; x being the easterly velocity component in the polar stereographic projection, y being the northerly velocity component, and mag being the magnitude. We also supply a PNG image for the magnitude with SAR backscatter intensity as the brightness. |