Richard Deurloo

On the Use of UAVs for Strapdown Airborne Gravimetry

Airborne gravimetry is a cost-effective technique to complement the gravity field information from satellite missions such as GRACE and, in the near future, GOCE. Measurements can be collected over regional areas in a relatively short time. Moreover, it is an especially useful method in remote areas and coastal water zones where terrestrial and ship-borne gravity measurements are difficult.

A Comparison of the Performance of Medium- and High-Quality Inertial Systems Grades for Strapdown Airborne Gravimetry

In 2010 and 2011 airborne field campaigns were carried out with the goal to assess and compare the performance of various GNSS/IMU systems for airborne gravimetry. These so-called strapdown gravimetry systems are less expensive, more compact and less power consuming, while being easier to install and operate, than spring gravimeters. Besides the quality of the IMU, the performance of a strapdown system depends on a number of factors, such as flight speed and flight altitude, as well as flight stability, among others. The results achieved showed that it is possible, with a simple set up based on only one GNSS antenna/receiver, and a medium cost IMU, to reach accuracies of a few miligal. This confirms the possibility to use medium cost strapdown systems for regional geoid improvement, in particular in areas lacking any other gravimetric data. The navigation grade IMUs, as expected, delivered better results. Comparison with the EGM2008 model showed an agreement better than 1 mGal over land and worst, of the order of a few mGal, in coastal areas. The paper also shows that with proper modelling and adequate filtering, good results can still be obatined even in more difficult/turbulent flight conditions.