Progress Update on the U.S. Gravity for the Redefinition of the American Vertical Datum (GRAV-D) Project and Lessons Learned for Geoid Modelling

English Abstract:

The U.S. National Geodetic Survey is collecting airborne gravity with the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) Project to produce a geoid supporting heights accurate to 2 centimeters where possible with a modernized U.S. vertical datum in 2022. This year GRAV-D will approach 50% of the country with airborne data collected to support the geoid, with over 75% of this data complete and publicly available. In this poster we provide an update on data collection status and present areas of known geoid improvement. We also discuss challenges faced when using airborne gravity to improve the geoid over a large, geographically diverse area with varying amounts of corroboratory data.