Background
Digital elevation models (DEMs) provide a high-resolution depiction of the land surface and are important to update in regions that change frequently. Volcanoes, geohazards, mining subsidence, and urban growth (plus more) all contribute to rapid changes in local topography. High-resolution DEMs have been requested in every Satellite Needs Working Group (SNWG) Assessment Cycle because they provide fundamental topographic underpinning for the processes that each land monitoring agency track. Agencies in the 2020 Assessment cycle expressed the need to track changes in topography over time: dynamic topography. The proposed SNWG-2020 activity would produce and distribute two 2.0 m DEM products: a near-Global Mosaic Earth DEM and DEM strips where new data was acquired for detailed change detection. The Global Mosaic EarthDEM product would be updated annually when new data are acquired. The DEM strips are at locations where Worldview collected stereo imagery. The two data products would be made available to Government agencies as per the licensing agreement.