VEHICULAR NAVIGATION IN URBAN CANYONS USING A HIGH SENSITIVITY GPS RECEIVER AUGMENTED WITH A MEDIUM-GRADE IMU

In order to improve performance, this paper investigates the augmentation of a HSGPS receiver with a medium-grade IMU and a map-matching technique. Most of the up-to-date work in the area of GPS/INS integration for vehicular navigation deals with cases when a vehicle is driven into downtown areas from open sky areas allowing accurate GPS initialization before the vehicle enters urban canyons. This research focuses on the problem that occurs when the navigation system is being initialized in a harsh downtown GPS environment and is calibrated while driving. Testing of the integrated system was performed in a downtown core with buildings of 10 to 70 stories and mask angles of up to 80 degrees. Results show that with the use of a HSGPS receiver it is possible to initialize the IMU while driving in an urban canyon and with the addition of a map-matching technique it is possible to reliably determine the street the vehicle is currently on.