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NCSA Special Seminar: "An embarrassment of riches: We now have better topography for the ice on Earth than the land"

Event Type
Lecture
Sponsor
NCSA
Location
NCSA auditorium
Date
Mar 11, 2020   1:00 pm  
Views
77
Originating Calendar
NCSA events

Paul Morin, who leads the Polar Geospatial Center at the University of Minnesota, will be presenting a seminar "An Embarrassment of Riches: We now have better topography for the ice on Earth than the land" on Wednesday, March 11 at 1:00 p.m. in the NCSA auditorium.

Abstract: For years, those of us that made maps of the poles apologized. We apologized for the blank spaces on the maps, we apologized for mountains being in the wrong place and out-of-date information. Over the past 10 years the situation improved. An image mosaic of Antarctica was built, airborne RADAR produced an improving view under the Antarctic ice sheet and a constellation of satellites started to stream data at ever higher resolution, at an increasing tempo and even during the long polar winters.

Now a diverse collaboration of U.S. science and intelligence agencies, universities and a geospatial software company has produced REMA—the Reference Elevation Model of Antarctica—and ArcticDEM, using open source software to extract Digital Elevation Models (DEM), or digital topography, from licensed imagery on Blue Waters at a resolution of two meters. The data have an accuracy of a foot and repeat coverage of 90% of the poles an average of 10 times over six years. This project was too large for any one agency, university or company. It required a large allocation on Blue Waters, four satellites that continuously collected sub-meter optical imagery for five years, two satellites that produced ground truth, 100Gbit networking and petabytes of storage.

We never thought that we would ever see a time when the science community has better topography for ice than land. Even we, the creators of REMA, are having a difficult time understanding what we have made. The use of it in logistics and facilities management was a surprise. We are as dumbfounded as anyone at the degree to which subsurface topography is expressed in ice sheet surface features. Incredibly, the volume of data and temporal depth of the DEM coverage is causing all of us to reassess how we manage and analyze geospatial in general.

We now apologize to the polar science community for a different reason. They have to keep up. And the current DEMs are only the beginning. We now face an avalanche of imagery and derived products in an increasingly complex landscape of small-sats launched by the dozen. It is a complex, exciting time.

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