Table of Contents

1. Contacts and Acknowledgments
2. Detailed Data Description
3. Data Access and Tools
4. Data Acquisition and Processing
5. References and Related Publications
6. Document Information

Citing These Data

The following example shows how to cite the use of this data set in a publication.

Cook, A. J., T. I. Murray, A. Luckman, D. G. Vaughan, and N. E. Barrand. 2012. Antarctic Peninsula 100 m Digital Elevation Model Derived from ASTER GDEM. Boulder, Colorado USA: National Snow and Ice Data Center. http://dx.doi.org/10.7265/N58K7711.

Overview

Platform	Terra
Sensor	Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)
Source Data	Global Digital Elevation Model (GDEM)
Spatial Coverage	Antarctic Peninsula Northernmost Latitude: 63°S Southernmost Latitude: 70°S Westernmost Longitude: 70° W Easternmost Longitude: 55° W
Spatial Resolution	100m
Temporal Coverage	2000 to 2009
Parameters	Elevation in meters above the WGS84 Ellipsoid, adjusted to the EGM96 Geoid
Data Format	GeoTIFF ASCII Text
Metadata Access	View Metadata Record
Data Access	FTP

1. Contacts and Acknowledgments

Investigators Name and Title

Alison Cook, Tavi Murray, and Adrian Luckman
Department of Geography
Swansea University
Swansea, SA2 8PP
United Kingdom

David G. Vaughan and Nicholas E. Barrand
British Antarctic Survey
High Cross, Madingley Road
Cambridge, CB3 0ET
United Kingdom

Technical Contact

NSIDC User Services
National Snow and Ice Data Center
CIRES, 449 UCB
University of Colorado
Boulder, CO 80309-0449  USA
phone: +1 303.492.6199
fax: +1 303.492.2468
form: Contact NSIDC User Services
e-mail: nsidc@nsidc.org

2. Detailed Data Description

This data set provides a high-resolution Digital Elevation Model (DEM) of the Antarctic Peninsula.

Format

The DEM is provided in GeoTIFF format and as an ASCII text file.

File and Directory Structure

Table 1 contains the descriptions of the files in the data set.

Table 1. File Description

File Name	Description
APDEM100m.tif	Final GeoTIFF file.
APDEM100m.aux APDEM100m.rrd APDEM100m.tif.xml	Ancillary GeoTIFF files aux: Auxilliary text file rrd: Pyramid file xml: XML file
APDEM100m_ascii.txt	DEM in ASCII text format.

 

File Naming Convention

File Size

Data files range in size from 1 KB to 209 MB.

Volume

The entire data set is approximately 600 MB.

Spatial Coverage

Antarctic Peninsula
Northernmost Latitude: 70°S
Southernmost Latitude: 63°S
Westernmost Longitude: 70° W
Easternmost Longitude: 55° W

Spatial Resolution

100 m

Projection and Grid Description

Projection: WGS84 Antarctic Polar Sterographic, Standard Parallel -71 deg South.

Grid: Surface elevation model, 1 Band, Continuous, Floating point, 32 Bit, 6164 columns, 8918 rows.

Temporal Coverage

This DEM is based on the ASTER GDEMv1, which uses scenes dating from 2000 to 2009. The dates of all scenes used to generate the GDEM in this region are not specified.

Parameter or Variable

Elevation in meters above the WGS84 Ellipsoid, adjusted to the EGM96 Geoid.

Parameter Range

0 to 3172 meters

3. Data Access and Tools

Data Access

Data are available via FTP.

Software and Tools

Data are readable using standard image processing software.

4. Data Acquisition and Processing

Data Acquisition Methods

Data used to created this DEM were modified from the ASTER Global Digital Elevation Model (GDEM).The ASTER GDEM is the most recently released nearly global elevation data set and is based upon a composition of automatically generated DEMs from ASTER stereo scenes acquired from 2000 to the present. It was produced by the Ministry of Economy, Trade and Industry (METI) of Japan and the United States National Aeronautics and Space Administration (NASA). Full details of the methodology for this data set are to be published in Cook, et. al., 2012.

Derivation Techniques and Algorithms

No formal ASTER GDEM validation has been performed over Antarctica, but it is evident that there are significant errors within the tiles throughout the Antarctic Peninsula region, introduced as a direct result of high reflectance and lack of features on snow-covered plateaus. Since conventional data correction techniques do not work in this region, a new approach was used to significantly improve the data set. Processing for the new DEM converted the GDEM into contours and removed the erroneous contours, producing a smooth and realistic new DEM from the remaining contours. This method was applied only to poor-quality regions of the GDEM, and the resulting DEMs were merged with the unaltered high-quality GDEM regions. See Figure 2 for the edited regions. The method is made possible by the fact that the high-artefact regions are those where the real-surface (as observed on the Landsat Image Mosaic of Antarctica [LIMA]) is smooth and has a low slope angle.

Processing Steps

ASTER GDEM tiles were downloaded from http://www.gdem.aster.ersdac.or.jp/ and mosaicked according to each latitudinal degree across the Antarctic Peninsula. Each mosaic was projected onto a reference system suitable for minimizing distortions in scale and for preserving angles locally. In this case, Lambert Conformal Conic (LCC) projection was used with standard parallels and other parameters according to latitude. The subsequent methodology was then applied separately to each latitudinal degree raster between 63 degrees and 70 degrees South.

Using a Geographic Information System (GIS), contours were generated automatically from the GDEM at 20 m intervals. A new file was then created by digitizing around regions of erroneous contours, based on the GDEM stacking number file and manual corrections using visible band imagery. These "noisy" regions of the DEM were then resampled to 200 m to simplify and remove gross errors, and sinks in the DEM were filled and smoothed. Contours at 20 m intervals were then created for this generalized DEM.

In order to correct these contours a slope model was created and contours that fell within a slope angle of greater than 20 degrees were removed. Secondly, contours less than 1 km in length were deleted, as these came from spikes or pits in the DEM. The surface topography was reconstructed by interpolation between the remaining contours, which represented consistent elevation values between the anomalies. The corrected regions of the DEM were then mosaicked with the remaining high-quality regions to create a topographically consistent DEM. The final step of the process involved reprojecting all tiles to a common reference system (Polar Stereographic projection with a standard latitude of 71 degrees South and a central meridian of 0 degrees), mosaicking all tiles and clipping to remove any remaining artifacts along the coast. The outer limit is based on the LIMA coastline with a 500 m buffer.

Error Sources

The new DEM has a mean elevation difference of - 4 m (±25 m Root Mean Square Error [RMSE]) from ICESat, and a horizontal error of less than 2 pixels, although elevation accuracies are lower on mountain peaks and steep-sided slopes. Some anomalies along the coast have been removed, resulting in small gaps, and the DEM has a small number of remaining artifacts. It only covers regions included in ASTER GDEM, in which there are inherent gaps and some missing islands.

Sensor or Instrument Description

Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) nadir and backward looking sensors. The data set was based on the ASTER Global Digital Elevation Model (GDEM) data.

5. References and Related Publications

ASTER GDEM Validation Team, 2009: METI/ERSDAC, NASA/LPDAAC, USGS/EROS. In cooperation with NGA and other collaborators. ASTER GDEM Validation Summary Report, 2009. Available at: https://lpdaac.usgs.gov/lpdaac/media/files/ASTER_GDEM_Validation_Summary_Report.pdf.

Cook, A. J., T. Murray, A. Luckman, D. G., Vaughan, and N. E. Barrand. 2012. A New 100-m Digital Elevation Model of the Antarctic Peninsula Derived from ASTER Global DEM: Methods and Accuracy Assessment, Earth Syst. Sci. Data, 4, 129-142, doi:10.5194/essd-4-129-2012.

Cziferszky, A., Fleming, A., and Fox, A. 2010. An Assessment of ASTER Elevation Data ove Glaciated Terrain on Pourquoi Pas Island, Antarctic Peninsula, in: Elevation Models for Geoscience, edited by: Gibbs, S., Geological Society Special Publications.

Hutchinson, M. F. 1989. A new Procedure for Gridding Elevation and Stream Line Data with Automatic Removal of Spurious Pits, J. Hydrol., 106, 211-232, 10.1016/0022-1694(89)90073-5.

Hvidegaard, S. M., Sorensen, L. S., and Forsberg, R. 2012. ASTER GDEM Validation Using LiDAR Data over Coastal Regions of Greenland, Remote Sens. Lett., 3, 85-91, 10.1080/01431161.2010.527389.

Kääb, A., Huggel, C., Paul, F., Wessels, R., Raup, B., Kieffer, H., and Kargel, J. S. 2002. Glacier Monitoring from ASTER Imagery: Accuracy and Applications, EARSeL eProceedings No.2, 43-53.

Liu, H. X., Jezek, K. C., and Li, B. 1999. Development of Antarctic DEM by Integrating Cartographic and Remotely Sensed Data: A GIS-based Approach, Journal of Geophysical Research, 104, 23199-23213.

Rees, W. G.: Assessment of ASTER Global Digital Elevation Model Data for Arctic Research, Polar Rec., 48, 31-39, 10.1017/s0032247411000325, 2012.

Reuter, H. I., Nelson, A., Strobl, P., Mehl, W., Jarvis, A., and Ieee. 2009. A First Assessment of ASTER GDEM Tiles for Absolute Accuracy, Relative Accuracy and Terrain Parameters, 2009. Ieee International Geoscience and Remote Sensing Symposium, Vols 1-5, IEEE, New York, 3665-3668.

Related Data Collections

• NSIDC DAAC Digital Elevation Models and Elevation Data
• Antarctic 1 km Digital Elevation Model (DEM) from Combined ERS-1 Radar and ICESat Laser Satellite Altimetry

Related Web Sites

• Antarctic Glaciological Data Center at NSIDC
• ASTER Global Digital Elevation Model (GDEM)

6. Document Information

Acronyms and Abbreviations

The acronyms used in this document are listed in Table 3.

Table 3. Acronyms and Abbreviations

Acronym	Description
AGDC	Antarctic Glaciological Data Center
ASTER	Advanced Spaceborne Thermal Emission and Reflection Radiometer
EGM96	Earth Gravitational Model 96
FTP	File Transfer Protocol
GDEM	Global Digital Elevation Mdoel
GIS	Geographic Information System
ICESAT	Ice, Cloud, and Land Elevation Satellite
LCC	Lambert Conformal Conic
LIMA	Landsat Image Mosaic of Antarctica
METI	Ministry of Economy, Trade and Industry
NSIDC	National Snow and Ice Data Center
RMSE	Root Mean Square Error
URL	Uniform Resource Locator

Document Creation Date

April 18, 2012

Document URL

http://nsidc.org/data/docs/agdc/nsidc0516-cook/index.html