A new approach for airborne vector gravimetry using GPS/INS

A new method for airborne vector gravimetry using GPS/INS has been develope d and the results are presented. The new algorithm uses kinematic accelerat ions as updates instead of positions or velocities, and all calculations ar e performed in the inertial frame. Therefore, it is conceptually simpler, e asier, more straightforward and computationally less expensive compared to the traditional approach in which the complex navigation equations should b e integrated. Moreover, it is a unified approach for determining all three vector components, and no stochastic gravity modeling is required. This app roach is based on analyzing the residuals from the Kalman filter of sensor errors, and further processing with wavenumber coefficient filterings is ap plied in case closely parallel tracks of data are available. An application to actual test-flight data is performed to test the validity of the new al gorithm. The results yield an accuracy in the down component of about 3-4 m Gal. Also, comparable results are obtained for the horizontal components wi th accuracies of about 6 mGal. The gravity modeling issue is discussed and alternative methods are presented, none of which improves on the original a pproach.