Abstract One of the most fundamental geophysical measurements of the Earth is that which describes the shape of its land surface. Topographical data are required by virtually all Earth science disciplines engaged in studies at or near the land surface. Topography is also civilization's most heavily used non-atmospheric geophysical measurement. NASA's Shuttle Radar Topography Mission (SRTM) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) projects have each completed independent near-global digital elevation measurements at comparable resolutions that approach 30 m spatially and 10 m vertically. Exploration of these datasets provides a new perspective of our planet. Fusion of these datasets will produce a more complete global elevation database, and differentiation of these datasets can be used to quantify select geomorphic processes.