Canadian Hydrographic Service BIOGRAPHY Mr. Gang Lu is a Research Associate in the

University of Calgary working in the area of precise GPS kinematic positioning and attitude determination. He completed an M.Sc. at The University of Calgary in 1991 in the area of GPS quality control. Dr. M. Elizabeth Cannon is an Assistant Professor in the same Department where she is responsible for teaching and research related to GPS. She has been involved with GPS research since 1984 and has published numerous papers on static and kinematic GPS positioning. Dr. Gerard Lachapelle is a Professor in the same Department where he responsible for teaching and research related to positioning, navigation and hydrography. He has been involved with GPS development and applications since 1980. Mr. Peter Kielland is a Hydrographic Development Officer with the Canadian Hydrographic Service. He holds a degree in Surveying and has extensive experience with marine navigation systems. He has been involved with GPS for over eight years. Multi-antenna GPS receiver configurations and methods are assessed to determine roll, pitch and azimuth of a survey launch operating at cruising speeds of 10 to 15 knots. Two receiver configurations are inter-compared, namely a 4-antenna Ashtech 3DF system and a 3-GPSCardTM configuration. The survey launch antenna configurations and marine trials conducted to test these systems are described. The approach used to resolve the relative carrier phase ambiguities between the antennas is discussed and the use of antenna baseline constraints is analyzed. A least squares procedure which utilizes all the position information from the antennas for the estimation of the platform attitude parameters and their accuracy is presented. The attitude determination results of the two systems tested are inter-compared and show that the rms agreement between the two receiver configurations is better than 7 arc minutes for the pitch and yaw components and approximately 15 arc minutes for the roll component