CRC-P-57322 High-resolution Real-time Airborne Gravimetry

Airborne gravimetry relies on removing inertial aircraft accelerations from total accelerations measured by an onboard gravimeter. NASA developed a Navigation Doppler Lidar ('NDL') for the US Space Program. The NDL measures velocities at the 1 mm/sec level in the laboratory, so such devices should be able to determine aircraft inertial accelerations much more accurately than is possible with GNSS data alone. A prototype NASA NDL was integrated with both stabilised platform and strapdown airborne gravimeters to acquire data in three airborne campaigns. We demonstrated that it is possible to consistently produce gravity data with lower noise over repeat lines by including NDL data with GNSS and gravimeter data in a Kalman filter, compared to using GNSS and gravimeter data alone. We also produced gravity data at sub-mGal noise levels using the NDL and gravimeter data without including GNSS data in the Kalman filter. This makes it feasible to undertake extra-terrestrial gravity surveys using the same instruments that are used for spacecraft navigation.