Low-cost Inertial Navigation Systems (INS) technology has evolved rapidly over the last decade with the development of less-expensive and higher-accuracy inertial measurement units (IMU). The development in the field of differential GPS (DGPS) has also matured over the past decade to provide reliable centimeter level accuracy in real-time. This dissertation provides a detailed study of the feasibility of using a low-cost IMU with accurate DGPS to achieve higher-accuracy, reliability, and continuity of the position solution.
Detailed INS equations are provided as well as the hardware integration of a low-cost IMU and a centimeter-level DGPS system.
The integrated system was dynamically tested in a van and a DC-3 research aircraft. In the absence of DGPS updates for a period of time of 10 seconds, IMU-derived positions diverged by 5-10 meters for the van tests and by tens of meters for flight tests.
Noise on the IMU-derived position between successive, one-second DGPS position updates was observed to be on the order of a few millimeters for the van tests and one centimeters for the flight tests.