Experimental Evaluation of Dual GPS for Heading Determination as a Compass Replacement in Unmanned Vehicles to Mitigate Electromagnetic Interference

In this paper, we discuss the experiment involving the use of two GPS devices as a compass replacement to determine heading direction. While heading direction can be easily determined using a compass sensor, there are scenarios where compasses may fail, especially in locations with strong magnetic fields. The primary concern addressed in this paper is the effectiveness of the dual GPS method as a compass sensor replacement and the determination of the optimal distance between the two GPS devices to maintain an acceptable heading error. Although heading direction can also be determined using a single GPS by calculating the movement from the current location to the previous one, this approach requires the GPS location to change, making it unsuitable for stationary autonomous vehicles. In our experiments, we placed two GPS devices at varying distances and calculated the heading direction based on the differences in their locations. The results of our testing revealed heading errors of 9°, 46.7°, 55.7°, 70.3°, 83.2°, 90.8°, and 161.6° for distances of 10m, 8m, 6m, 5m, 3m, 1m, and 0.4m, respectively. Based on our experiments, we determined that the minimum acceptable distance between the two GPS devices is 10m for reliable heading direction estimation.