Gravity measurement from moving platform by Kalman Filter and position and velocity corrections for earth layer monitoring to earthquake and volcano activity survey

Gravity measurement responds to changes in subsurface density and characteristics and is a non-invasive and cost effective way to identify and characterize subsurface. Gravity measurement is an effective tool for earth layer monitoring to earthquake and volcano activity survey. It is particularly important for gravity observation from moving platforms, especially for remote and offshore areas by aircraft, boat, ship, submarine, vehicle, satellite, etc. The measurement is complicated by difficulty to discern gravity from platform accelerations, nonlinearity, drift and dynamic angular movement. Presented solution is second order Kalman Filter, a recursive estimator that is applied to highly nonlinear measurement problems. The filter optimally combines data of three-axis gyros, accelerometers and platform position and velocity signals to provide accurate attitude and gravity measurement. Extensive simulations verified accuracy and robustness of proposed method for measurement from different vehicles in various dynamic environments.