REMA

The Reference Elevation Model of Antarctica (REMA) is a high resolution, time-stamped Digital Surface Model (DSM) of Antarctica at 2-meter spatial resolution.

Want to jump right to the data?
We encourage you to read this documentation, but the link is provided below.

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Browse AWS STAC Catalog

REMA EXPLORER

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Overview

Purpose

The Reference Elevation Model of Antarctica (REMA) provides the first, high resolution (2-meter) terrain map of nearly the entire continent. Since each REMA grid point has a timestamp, any past or future point observation of elevation provides a measurement of elevation change.

REMA may provide corrections for a wide range of remote sensing processing activities, such image orthorectification and interferometry, and provide constraints for geodynamic and ice flow modeling, mapping of grounding lines, and surface processes. REMA also provides a powerful new resource for field logistics planning.

Source

REMA is constructed from hundreds of thousands of individual stereoscopic Digital Elevation Models (DEM) extracted from pairs of submeter (0.32 to 0.5 m) resolution Maxar satellite imagery, including data from WorldView-1, WorldView-2, and WorldView-3, and a small number from GeoEye-1, acquired between 2009 and 2021 over the austral summer seasons (mostly December to March).

Each individual DEM was vertically registered to satellite altimetry measurements from Cryosat-2 and ICESat, resulting in absolute uncertainties of less than 1 m over most of its area, and relative uncertainties of decimeters.

Processing

REMA is generated by applying fully automated, stereo auto-correlation techniques to overlapping pairs of high-resolution optical satellite images.

Using the open source Surface Extraction from TIN-based Searchspace Minimization (SETSM) software, developed by M.J. Noh and Ian Howat at the Ohio State University, stereopair images were processed to Digital Elevation Models using compute resources provided through an Innovation Allocation on the Blue Waters supercomputer located at the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign.

Output

Output DEM raster files are being made available as both “strip” files as they are output directly from SETSM that preserve the original source material temporal resolution, as well as mosaic files that are compiled from multiple strips that have been co-registered, blended, and feathered to reduce edge-matching artifacts.

The time-dependent nature of the strip DEM files allows users to perform change detection analysis and to compare observations of topography data acquired in different seasons or years. The mosaic DEM tiles are assembled from multiple strip DEMs with the intention of providing a more consistent and comprehensive product over larger areas, while also providing a time stamp and error estimate for each pixel to enable to change detection. The tile data are registered to satellite altimetry to increase their absolute accuracy while strips are not. Registration data for strips may be provided in later REMA versions.

Documentation

Refer to these documents and guides for official REMA information & citation.

PGC’s DEM Products Guide 

PGC Acknowledgement Policy 

Citation

Along with acknowledging the PGC, the REMA dataset should be cited as follows:

Strips:

Howat, Ian, et al., 2022, “The Reference Elevation Model of Antarctica – Strips, Version 4.1”, https://doi.org/10.7910/DVN/X7NDNY, Harvard Dataverse, V1, [Date Accessed].

Mosaics:

Howat, Ian, et al., 2022, “The Reference Elevation Model of Antarctica – Mosaics, Version 2”, https://doi.org/10.7910/DVN/EBW8UC, Harvard Dataverse, V1, [Date Accessed].

Current Release

October 2022 Release

REMA elevation products are updated to reflect expanded temporal ranges and improved mosaicking methods. The current release includes all previous coverage, spanning 12 years, and for the first time includes subantarctic islands near South America.

DEM Strips

Version s2s041 – Supersedes all REMA v1 strip data

DEM  mosaics

Version 2 – New methodology applied

See PGCs DEM Product Guide for more information

REMA Strips

Strip DEM files correspond to the overlapping area of the input stereoscopic imagery pair strips as they are collected by Maxar’s constellation of polar-orbiting satellites. Strip DEM dimensions will vary according to the satellite sensor that acquired the images and the off-nadir angle of collection. Most strips are between 13 km and 17 km in width, and 110 km and 120 km in length.

Strip DEM files are provided at 2-meter resolution in 32-bit GeoTIFF format. Elevation units are meters and are referenced to the WGS84 ellipsoid. No ground control or altimetry registration has been applied to the strips.

STATISTICS
TOTAL STRIPS
311,892
TOTAL STRIP DEM FILE SIZE
104 TB
DOWNLOADS

REMA Strip DEM extent index
(SHP | GDB | GPKG | PARQUET)

Download from AWS

REMA Strip Coverage (Release Oct 2022)
REMA Strip Density (Release Oct 2022)

REMA Mosaic

Version 2 Mosaic

Mosaicked DEM files are compiled from the entire stack of strip DEMs as source data. The height value for each pixel in the mosaic is derived from the median value of all contributing strip DEMs, in an effort to extract a consistent surface with low sensitivity to outlying height values. As a result the REMA mosaics include DEMs from austral summer season where the sun elevation is sufficiently high to acquire satellite imagery.

Mosaicked DEM files are distributed at full 2-meter spatial resolution as 50 km x 50 km tiles in 32-bit GeoTIFF format. Reduced resolution versions are also available at 10-meter and 32-meter as 100 km x 100 km tiles, and full-domain 100-meter, 500-meter, and 1-kilometer mosaics. Elevation units are meters and are referenced to the WGS84 ellipsoid.

REMA Mosaic Coverage (Release Oct 2022)
STATISTICS
Version 2 – TOTAL MOSAIC TILES (2m)
5,801
TOTAL MOSAIC TILE FILE SIZE
8.4 TB
DOWNLOADS

REMA Mosaic DEM extent index
(SHP | GDB | GPKG | PARQUET)

REMA Mosaic DEMs available at multiple resolutions (browser)

Download from AWS

VRTs
( 2m | 10m | 32m )

Explore Data

PGC and ESRI developed web services and applications in support of REMA data that, in addition to providing raw download capability, can be used to view, explore and perform basic analysis and geoprocessing tasks.

REMA Explorer

The REMA Explorer is the best way to preview the datasets if no GIS or remote sensing software is available or you simply want to explore the entire dataset quickly. The full-resolution REMA strips and mosaics are presented in this web map to quickly preview and explore the elevation data. With this web map, users can visualize the REMA data, preview the spatial coverage, and download simple exports.

There is no login required but if you download or use any REMA data from the app (or otherwise), you must adhere to PGC’s Acknowledgement Policy.

REMA EXPLORER

ArcticDEM Explorer
The REMA Explorer, developed by PGC and Esri, allows for visualization and download of REMA products.

Download from PGC

REMA Strip DEM extent index – with data download links (SHP | GDB | GPKG)

REMA Strip DEM data download via HTTP (browser): https://data.pgc.umn.edu/elev/dem/setsm/REMA/strips/latest/2m

REMA Mosaic DEM extent indexes – with data download links (SHP | GDB | GPKG)

REMA Mosaic DEM data download via HTTP (browser): https://data.pgc.umn.edu/elev/dem/setsm/REMA/mosaic/latest

Bulk Download

Use the links below to browse the directory for the entire REMA dataset. Refer to the User Documentation to see the directory structure, naming schemes, and download contents.

HTTP: https://data.pgc.umn.edu/elev/dem/setsm/REMA

Users familiar with the GNU Wget utility can use the following commands to batch download REMA data. There is also a Windows version.

Please note, the first two commands will download the entire dataset, which is over 200 TB for strips and 20 TB for mosaics. Use the subdirectory examples to limit your download.

2-meter strips (entire dataset!)
wget -r -N -nH -np -R index.html* --cut-dirs=3 https://data.pgc.umn.edu/elev/dem/setsm/REMA/strips/s2s041/2m/
2-meter mosaic tiles (entire dataset!)
wget -r -N -nH -np -R index.html* --cut-dirs=3 https://data.pgc.umn.edu/elev/dem/setsm/REMA/mosaic/v2.0/2m/
2-meter strips (subdirectory example)
wget -r -N -nH -np -R index.html* --cut-dirs=3 https://data.pgc.umn.edu/elev/dem/setsm/REMA/strips/s2s041/2m/s72e155/
2-meter mosaic tiles (subdirectory example)
wget -r -N -nH -np -R index.html* --cut-dirs=3 https://data.pgc.umn.edu/elev/dem/setsm/REMA/mosaic/v2.0/2m/18_28/

Download from AWS

Strip DEMs available at 2-meter resolution.

All publicly-available DEM data from our projects are also hosted in an open AWS bucket and indexed with a STAC catalog. DEM data assets can be identified using the DEM STAC items and downloaded or used directly in the cloud.

REMA AWS Open Data Registry page:

Download from OpenTopography

OpenTopography is distributing the REMA mosaics (version 2, released October 2022) with value-added tools for access, processing, and visualization.

32m and 10m resolution data products are open to all users.
2m resolution data products are restricted to education and research users.

OpenTopography REMA page:

VRTs

Users can directly load the mosaic tiles into certain GIS programs and applications without downloading data by using GDAL’s Virtual Format.

REMA VRT files representing 2, 10, and 32-meter resolution mosaics:

Reference these VRTs in the cloud from your GIS or application or download them locally. Note they can be slow to load initially.

Web Services & Applications

Need help connecting to web service layers? Check out PGC’s guide to using web services in ArcGIS and QGIS to get you started.

REMA 2m Strip Index

REMA 2m Tile Index

REMA Mosaic-only Image Service:

REMA composite (strip and mosaic) Image Service

Maps

Map Poster

A shaded relief map poster of the REMA dataset with voids filled and the resolution reduced to 500 meters is available as a 44″x36″ map poster. There are two versions, one that contains cartographic elements such as place name labels, graticules, and facilities, and one that is just the shaded relief image. The maps can be downloaded below.

Shaded Relief Version


View Map
Download Map

Cartographic Version


View Map
Download Map

Large-Format Prints

If the above format isn’t large enough for you, a number of high-resolution images have been created to be printed on a large-format plotter for display on a floor or a large wall. The full continent of Antarctica is available as three strips sized at 36″x132″ with a final size of 9’x11′ when fully assembled. The Antarctic Peninsula and the Thwaites/Pine Island Glacier area of West Antarctica are also available.

All files are downloadable with the links below in .jpg format. Please note: file sizes may be up to 50 Mb.

Large-format prints of the Reference Elevation Model of Antarctica. source: Paul Morin, Polar Geospatial Center

Press

Video
Audio

Dr. Ian Howat, the REMA Principal Investigator and Professor of Earth Sciences at Ohio State University, was featured in BBC Newsday episode Russia Gears Up for Biggest War Games Since Cold War. If the audio fails to load, you can listen to the original broadcast at this link: https://www.bbc.co.uk/radio/play/w172w1fpjz11zwf/ (9/11/2018)

Length: 3:48

Articles
From PGC