Available data may include airborne and terrestrial survey information, gravity data, and gravity-based geoids or datums. Open the GRAV-D Data Products Dashboard by selecting the hyperlink or the map below. Once the dashboard opens, select the block of interest in the map or list on the left. The right hand panel will populate with general information and a link that will lead to data available for download.
The General User Manual, which describes data distribution, field operation details, post-processing, and how to calculate commonly used gravity values, is available below. User Manuals for each block, which describes specific collection and error details for those data, are included in the zip file when the data is downloaded. Each User Manual specifies which version of the General Manual applies to that data set.
Starting in 2014, the National Geodetic Survey (NGS) began publishing a series of experimental geoid (xGEOID) models annually. The xGEOID models are continually improved each year and each subsequent model incorporates the new airborne gravity data that are released within the preceding year.