Gravitational Terrain Correction
Developing an algorithm for Gravitational Terrain Effect Computation
Angeli M.2023
Gravitational terrain correction is a process of removing the gravitational effects of local topography from gravity measurements. This is necessary because gravity measurements are influenced by the surrounding terrain, and these variations can mask the gravitational anomalies caused by subsurface geological features.
Our office offers hi precision estimation of geoid, based on Hammer's method. Hammer's method (1939) is a classic approach for calculating terrain corrections, using a template (Hammer net) to subdivide the area around the station into compartments. The effect of terrain is most significant for nearby features due to the inverse square law of gravity.
For each gravitational project, a hammer net will be built based on coordinates of gravity stations. A table with thousand nodes is created, for a net with radius up to 22 km. The altitude of each node will be extracted from terrain models. The next step of processing is to calculate density variations in triangular prisms.
The Bouguer correction removes the general effect of elevation, while the terrain correction refines this by accounting for local variations in topography. Both corrections are crucial for accurately interpreting gravity data and understanding subsurface structures.