Measurement level integration of multiple low-cost GPS receivers for UAVs

UAVs are increasingly being used outdoors for surveillance, exploration, search, rescue and other purposes. A good position estimate allows us to precisely navigate and avoid objects, thus maximising the potential of autonomous applications. There is a growing need for an inexpensive, high performance GPS solution providing better accuracy and robustness. In this paper we incorporate measurements from multiple low-cost, lightweight receivers using an Extended Kalman Filter (EKF). The estimates from the EKF are then compared to the estimates from just one receiver. Experiments are conducted by placing five u-blox receivers on a quadrotor, one on each arm and one at the center. The results show an improvement in accuracy and robustness while using multiple receivers.