DEM sourcing guidelines for computing 1Â Eö accurate terrain corrections for airborne gravity gradiometry

The four study areas are presented as reference material for processing airborne gravity gradiometry data at the 1 Eö noise level with 50 m spatial resolution. From this investigation we find that to achieve 1 Eö accuracy in the terrain correction at 80 m height airborne LiDAR data are required even when terrain relief is a few tens of meters and the vegetation is sparse. However, as satellite ranging technologies progress bare-earth DEMs of sufficient accuracy and resolution may be sourced at lesser cost. We found that a bare-earth DEM of 10 m resolution and 2 m accuracy are sufficient for achieving 1 Eö accuracy in the terrain correction independent of relief or vegetation cover. For AGG systems operating at greater noise levels the 3 arc-second SRTM is adequate for areas having tens of meters of relief and sparse vegetation and even for areas of greater relief and sparse vegetation if a constant elevation survey is flown at 80 m above terrain peak.