SRTM2gravity (2018)

SRTM2gravity is a new 3" global model of gravity implied by Earth’s topographic masses. It represents a novel global data source for complete gravimetric terrain corrections suitable to reduce gravimetric surveys in geodesy and geophysics around the globe, or the creation of ultra-detailed gravity maps. The SRTM2gravity project is the first-ever successful attempt to compute and release the gravity field generated by the topography from the Shuttle Radar Topography Mission (SRTM) at 3” (about 90 m) spatial resolution globally. Two main SRTM2gravity products have been developed: These are 1) full-scale gravity effects reflecting the total gravitational attraction of Earth’s global topography, and 2) residual (=short-scale = RTM) gravity effects containing short-wavelength gravitational signals only, at spatial scales less than ~10 km. The first product is equivalent to (complete) gravimetric terrain corrections. It contains both the linear gravity effect of the topography (known as Bouguer shell) as well as the non-linear effect (classically denoted as terrain correction in textbooks), so can be used to easily remove the topographic signal from observed gravity values. We have released our model at 3" resolution into the public domain for free use in science, teaching and by industry. The data are available here. The SRTM2gravity model uniquely unites local resolution (3") with global coverage. SRTM2gravity conceptually improves over previous efforts, notably the 7.2" GGMplus gravity model, in three aspects: These are a) the use of more mature modelling techniques, b) the use of improved and cleaned topographic input data and c) ultra-fine 90 m instead of ~220 m detail, capable of better representing very short-scale terrain-induced gravity effects (see Figure 1 here ).