Experiences with AIRGrav: Results from a New Airborne Gravimeter

The results of the evaluation of a new airborne gravimeter developed by Sander Geophysics Limited (SGL) will be presented. This gravimeter is based on a platform type inertial navigation system, and is optimised for the airborne environment. A general description of the instrument is given.The testing was conducted over a relatively flat area which is well covered with ground gravity values. The upward continuation to flying height of a grid of these values was used as a reference for the data reduction. The gravity anomaly was extracted through application of a series of low-pass filters on the inertial data, after removal of the kinematic accelerations and Coriolis effects using the processed GPS data. The results show an agreement with the ground truth well within 1.0 mGal for a 2km half wavelength spatial resolution. The effects of varying flight conditions are assessed as to their impact on the quality of the data. Flight turbulences appear to have very little effect on determination of the gravity anomaly for half wavelengths as short as 2 km.