Call for Participation – Kinematic GPS Challenge

The National Geodetic Survey (NGS) is conducting a 12-year project to re-define the vertical datum of the US. This project, referred to as GRAV-D (Gravity for the Redefinition of the American Vertical Datum;, is accomplished by flying airborne gravity missions over the continental and coastal US. Gravity solutions require accurate sensor positioning and accelerations, which in turn requires precise and accurate GPS solutions for the aircraft.

To help us facilitate our software and method development, we invite interested researchers and practitioners to compute and submit solutions from samples of actual GRAV-D data. A number of kinematic techniques and methods suited for long distance flights have emerged over the past few years. Given the challenging nature of these flights (long distances, high altitudes, varying tropospheric regimes) and the importance to GRAV-D, we believe applying these techniques to such a common data set would also be of great interest to the kinematic community.

This is a strictly voluntary exercise for those interested in such a comparison and we will share our results with the participants. We are also interested in possibly co-authoring a publication with the participants on the topic if results are significant.

Additional information, including a description of the test as well as the test data set, is available at the following FTP site:

Please read through the test description and email Gerry Mader ( if you plan to participate or if you have any questions. Also, please feel free to forward this announcement to anyone or group who you think might be interested but might not be on this mailing list. We look forward to your participation!