Ice Sheet Monitoring Using Latest Generation SAR Satellites

Abstract:

Remote sensing is a crucial component to gain insight in the worlds ice sheets and glaciers. Spaceborne Synthetic Aperture Radar data have proven to be a key resource to monitor the great ice sheets in Antarctica and Greenland. International efforts undertaken during the last International Polar Year resulted in the collection of vast amounts of data to generate the first continent-wide ice velocity map of Antarctica, a series of full velocity maps of Greenland, and time series data in key regions. The Antarctic grounding line was also mapped at unprecedented accuracy using InSAR. The end of several SAR missions since 2010 has posed a significant challenge in the effort to provide ongoing data acquisitions.

New generation missions show potential to not only fill the data gap, but to make the collection of ice sheet data part of the ongoing acquisition scenarios, therefore ensuring data continuity. New modes, like the TOPSAR mode used for Sentinel-1A, provide new opportunities but also pose processing challenges, particularly if the entire area monitored is in motion. Several future missions are in various stages of development, thus further adding to the suite of sensors potentially available to collect data in Polar Regions going forward. The NASA-ISRO L-and S-band mission, planned for launch in 2020, will be a pure science mission with an open data policy, thus again changing the data availability and data access situation for the better.

In international collaboration through the Polar Space Task Group, space agencies coordinate their science acquisitions in Polar Regions. With broad input from the larger ice sheet science community, we have worked closely with space agencies to define science requirements and to develop acquisition scenarios that maximize science value for ice sheets.

Here we highlight the collaboration effort, summarize the input of the ice sheet science community to the Polar Space Task Group, and present the acquisition plans that resulted from these efforts. Based on recent acquisitions, we also demonstrate how the current generation of SAR satellites will be used to provide Earth System Science Data for ice sheets and how they fit into existing data. We will show results based on Sentinel-1A, ALOS-2 PALSAR-2, COSMO-SkyMED and TerraSAR-X, TanDEM-X and contrast sensor specific data processing.