[G02-2] Gravimetry

[G02-2-02] A Comparison of Airborne Vector Gravimeter Measurements with the NOAA Geoid Slope Validation Survey 2014

Stephen Ferguson¹, ^○Yan Ming Wang², Stefan Elieff¹, Simon Holmes³, Xiaopeng Li⁴, Kevin Ahlgren², Ruifeng Xi¹ (1.Sander Geophysics Ltd., Ottawa, Canada, 2.The National Geodetic Survey, Silver Spring, MD USA, 3.SGT Inc. Greenbelt MD USA, 4.DST Inc. Silver Spring MD USA)

Gravity measurements made from aircraft are becoming widely used in combination with satellite and terrestrial data for geoid computation. At present, only measurements of the vertical component of the gravity vector are used for this purpose. Incorporation of the horizontal components of the vector offers the opportunity to strengthen the geoid solution, and minimize edge effects at the survey boundaries. Most airborne gravity meters do not offer the possibility of measuring all three components of gravity, however the AIRGrav system developed by Sander Geophysics has shown the ability to routinely obtain repeatability at the sub-milliGal level, with suitable processing.

This presentation will focus on a direct comparison of airborne measurements flown on a repeat track over the GSVS2014 test line located in Iowa, USA. The high-accuracy GSVS2014 ground data will be upward continued to the flight elevation for comparison with the measured airborne gravity components (equivalent to magnitude and deflection of the vertical). The airborne data will also be compared with the latest gravity models, including EGM2008, EIGEN6c4, and the current NOAA model xGEOID17. The vector airborne data will also be incorporated into a gravity model to assess their contribution.