<h2>AAS 97-112</h2>
<h2>77 GPS ATTITUDE AND NAVIGATION EXPERIMENT (GANE)                                                                                                 </h2>
<h4> M. E. Lisano, McDonnell Douglas Aerospace; J. R. Carpenter, NASA Johnson Space Center                                                                                    </h4>
<h2> Abstract </h2>
 A recent Shuttle mission, STS-77, offered the first opportunity for operational use  of the "dynamic" Wide-Area Differential GPS (DWA DGPS) orbit determination  technique.  The mission carried the GPS Attitude and Navigation Experiment (GANE),  one of a series of risk mitigation experiments being performed by the Shuttle  program for the International Space Station.  GPS coarse acquisition pseudoranges  were processed and four orbit arcs were generated.  A modest-fidelity dynamic model  consisting of 30x30 gravity, attitude-dependent drag, and modelling of CG-to-GPS  antenna offset, were used in the filter.  Assessments of the DWA DGPS filter  performance are discussed.