HR: 0800h
AN: G41A-0351    [Abstracts]
TI: Full 6-D characterization of ship motion using GPS & INS
AU: * Thomsen, D R
EM: dthomsen@ucsd.edu
AF: IGPP - Scripps Institution of Oceanography, MC 0225 9500 Gilman Drive, La Jolla, ca 92093-0225 United States
AU: Chadwell, C D
EM: cchadwell@ucsd.edu
AF: MPL - Scripps Institution of Oceanography, MC 0205 9500 Gilman Drive, La Jolla, CA 92093-0205 United States
AU: Sandwell, D T
EM: dsandwell@ucsd.edu
AF: IGPP - Scripps Institution of Oceanography, MC 0225 9500 Gilman Drive, La Jolla, ca 92093-0225 United States
AB: Full characterization of the motion of a ship is required for various oceanographic and engineering activities including marine geodetic surveys [Chadwell and Bock, 2001; Chadwell et al., 1995; Spiess et al., 1998], synthetic aperture sonar processing [Asada and Yabuki, 2001] and instrument calibration. Reconstruction of the ship-position requires knowledge of both the motions of the center of the coordinate system of the ship and the roll, pitch and yaw of the ship about the center. The feasibility of 1 Hz. sampled 3-D ship position measurements at centimeter-scale resolution using a triad of precisely positioned kinematic GPS receivers has been demonstrated [Chadwell, 2003; Chadwell and Bock, 2001]. Additionally, there exists onboard inertial navigation system (INS) instrumentation measuring pitch, yaw, and roll of the ship in the forms of a PHINS strapdown package. These data have a nominal sample interval of 10 Hz. Used together, the 1 Hz GPS position measurements and the 10 Hz angular and inertial measurements provide a good estimate of the full 6-D ship motion. As the characterization is completed in the post-processing, the position estimation at any point in time can utilize data both preceding and postdating that time rather than being limited by a forward predictive filter set such as is traditionally used in INS/GPS integration. We discuss the integration of the two datasets and the expected accuracy of the final integrated set. We further demonstrate the adaptation and limitations of using a single GPS receiver combined with the inertial and unfiltered angular measurements to predict the full 6-D ship motion. We briefly describe the theory of motion reconstruction and the techniques used to recover the full ship motion using first the combination of the three-GPS and INS data and later the one-GPS/INS integration.
DE: 1294 Instruments and techniques
DE: 1295 Integrations of techniques
DE: 4294 Instruments and techniques
SC: Geodesy [G]
MN: Fall Meeting 2005