| A real-time DGPS/INS integrated system has been designed, implemented and tested using a LTN-90-100 IMU, two Ashtech Z-XII receivers and two 486/66 computers as the major hardware components of the system. The principles of single differential GPS positioning, strapdown INS navigation and the methodology of GPS/INS integration are discussed as essential background material for the research. The research itself addresses the problems of hardware and software integration for the specific DGPS/INS system implementation chosen, justifies the choices made, and discusses in detail the GPS correction creation and transmission issues. Tests have been designed and conducted to verify the system design and assess the system performance. Results show that the achieved accuracy is metre-level in position, cm-level in velocity, 10 arcsec-level in pitch and roll and 0.08 degree in azimuth with respect to a DGPS/INS system using GPS carrier phase data. |
