The Reference Elevation Model of Antarctica (REMA) is a

digital elevation model A digital elevation model (DEM) or digital surface model (DSM) is a 3D computer graphics representation of elevation data to represent terrain or overlaying objects, commonly of a planet, Natural satellite, moon, or asteroid. A "global DEM" refer ...

(DEM) that covers almost the entire continent of Antarctica at a resolution of less than 10 m.

Model

REMA uses

stereophotogrammetry Photogrammetry is the science and technology of obtaining reliable information about physical objects and the environment through the process of recording, measuring and interpreting photographic images and patterns of electromagnetic radiant ima ...

to provide high-quality surface measurements of the surface of the ice sheet that covers most of the continent, despite the low contrast of the satellite images. Elements of the mosaic include an error estimate and a time stamp, so changes in the ice or snow surface can be measured. Absolute uncertainty should be less than 1 meter, and relative uncertainties should be in decimeters. The satellite images have pixel ground resolutions of under 0.5 meters, and overlapping images from different angles can be used to extract elevation data for DEMs. Based only on satellite position, there may be errors of several meters, but through ground control registration these can be reduced to point-to-point errors of 20 centimeters or less, comparable in accuracy to airborne

lidar Lidar (, also LIDAR, an acronym of "light detection and ranging" or "laser imaging, detection, and ranging") is a method for determining ranging, ranges by targeting an object or a surface with a laser and measuring the time for the reflected li ...

. Most of the initial data was collected over the austral summer seasons of 2015 and 2016. The model is updated with new DEM strips twice per year. Derived mosaic products are added as they become available.

Data sources and licensing

REMA was built using stereoscopic imagery from the

WorldView-1 WorldView-1 (WV 1) is a commercial Earth observation satellite owned by DigitalGlobe. WorldView-1 was launched on 18 September 2007, followed later by the WorldView-2 in 2009. First imagery from ''WorldView-1'' was available in October 2007, prior ...

WorldView-2 WorldView-2 (WV 2) is a commercial Earth observation satellite owned by DigitalGlobe. WorldView-2 provides commercially available panchromatic imagery of resolution, and eight-band multispectral imagery with resolution. It was launched 8 Oct ...

WorldView-3 WorldView-3 (WV 3) is a commercial Earth observation satellite owned by DigitalGlobe. It was launched on 13 August 2014 to become DigitalGlobe's sixth satellite in orbit, joining Ikonos which was launched in 1999, QuickBird in 2001, WorldView-1 i ...

and

GeoEye-1 ''GeoEye-1'' is a high-resolution Earth observation satellite owned by Maxar Technologies (formerly DigitalGlobe), launched in September 2008. The satellite was acquired in the 2013 purchase of GeoEye. History On 1 December 2004, General Dynam ...

satellites, operated by

DigitalGlobe DigitalGlobe was an American commercial vendor of space imagery and geospatial content, and operator of civilian remote sensing spacecraft. The company went public on the New York Stock Exchange on 14 May 2009, selling 14.7 million shares at U ...

. The images are distributed by the

Polar Geospatial Center The Polar Geospatial Center is a research center at the University of Minnesota's College of Science and Engineering funded by the National Science Foundation's Office of Polar Programs. Founded in 2007, the Polar Geospatial Center "provides ge ...

at the University of Minnesota College of Science and Engineering under a scientific use licensing agreement with the United States

National Geospatial-Intelligence Agency The National Geospatial-Intelligence Agency (NGA) is a combat support agency within the United States Department of Defense whose primary mission is collecting, analyzing, and distributing geospatial intelligence (GEOINT) to support national se ...

. The stereopair images were processed by software developed at the

Ohio State University The Ohio State University (Ohio State or OSU) is a public university, public Land-grant university, land-grant research university in Columbus, Ohio, United States. A member of the University System of Ohio, it was founded in 1870. It is one ...

to create DEMs using the

Blue Waters Blue Waters was a petascale supercomputer operated by the National Center for Supercomputing Applications (NCSA) at the University of Illinois Urbana-Champaign. On August 8, 2007, the National Science Board approved a resolution which authorize ...

supercomputer at the

National Center for Supercomputing Applications The National Center for Supercomputing Applications (NCSA) is a unit of the University of Illinois Urbana-Champaign, and provides high-performance computing resources to researchers in the United States. NCSA is currently led by Professor Bill ...

at the

University of Illinois Urbana-Champaign The University of Illinois Urbana-Champaign (UIUC, U of I, Illinois, or University of Illinois) is a public university, public land-grant university, land-grant research university in the Champaign–Urbana metropolitan area, Illinois, United ...

. The images are available only to US federally funded investigators, but the derived products, including DEMs, are distributed openly.

REMA Explorer

The Polar Geospatial Center supports a REMA Explorer application that lets public users browse the data online. They can enter coordinates or a place name to zoom in on a small area, and choose different renderings such as hill shades, elevation tinted, contour. They can obtain information about any point of the ice surface, including resolution, aspect, slope, ellipsoid height and orthometric height.

References

Sources

* * * * * {{refend Geography of Antarctica Digital elevation models