GPS-Aided Inertial Navigation Avionics (GAIA) Integrated with MSAS and Maritime DGPS Beacon

Hiroshi Tomita, Masatoshi Harigae, Koji Kokue and Yoshiaki Shiozawa

Abstract:	The JAXA (changed from the National Aerospace Laboratory of Japan) has developed a GPS Aided Inertial navigation Avionics (GAIA) for over 10 years. GAIA utilizes a carrier phase DGPS/INS (CDGPS/INS) algorithm and its accuracy is better than 1m for each axis. In UAV program called the High Speed Flight Demonstration (HSFD), a demonstrator made auto landing using GAIA in 2002. To promote the flight safety of general aviation, navigation system with high accuracy and reliability must be supplied in low cost. Also, small size, light weight and low power consumption are also important items for small aircrafts and UAV. The GAIA equipment for HSFD was expensive and heavy as ordinary INS. To reduce cost and weight, we changed the ring laser gyro built into GAIA equipment from Kearfott T-24 (0.8 n.m./h class) to small and low cost T-16B (20 n.m./h class). The new GAIA equipment weights 6 kg, significantly smaller than 9.8 kg of the former model. Despite the lower grade gyro, we achieved to maintain the navigation performance by the following methods. (1) The error dynamics of T-16B gyro such as random walk was identified precisely. (2) Through the sensitivity analysis of the error estimation filter, we defined the filter parameters to minimize the effect of random walk error. Ashtech DG16 made by Thales Navigation is used for the build-in GPS, SBAS and maritime DGPS beacon receiver. DG16 can receive MSAS, a SBAS by Japan. To add the maritime beacon DGPS function, we expanded the mode switching algorithm of GAIA navigation processor. In a ground test in stable condition for 14 hours, we found 95% position error of the beacon DGPS/INS integrated navigation showed a good result, 0.76m for latitude, 0.63m for longitude and 1.57m for altitude. A dynamic test result using an automobile was also good. We are planning flight tests as a next step. Through the development, we established the design method to tune the filter parameters and bring out the maximum navigation performance even with the middleclass gyro.
Published in:	Proceedings of the 17th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2004) September 21 - 24, 2004 Long Beach Convention Center Long Beach, CA
Pages:	277 - 284
Cite this article:	Tomita, Hiroshi, Harigae, Masatoshi, Kokue, Koji, Shiozawa, Yoshiaki, "GPS-Aided Inertial Navigation Avionics (GAIA) Integrated with MSAS and Maritime DGPS Beacon," Proceedings of the 17th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2004), Long Beach, CA, September 2004, pp. 277-284.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In