Low-cost differential GPS for field robotics

In this paper we detail the design and implementation of a Differential GPS system that uses only low-cost, light-weight and widely available GPS modules. Such a system is desirable for modern field robotics in order to improve the performance of mapping, navigation, collision avoidance and other common tasks, especially on payload-constrained robots. The particular noise and error modes present in the low-cost system are investigated and algorithms introduced to minimise their effect. The system is demonstrated in the context of field robotics for stationary, ground-based and airbourne agents. It is found that the majority of the error due to the low cost components can be manipulated to be of a form easily mitigated for most robots. The system is shown to provide good results in the horizontal plane in open environments such as those typically used for outdoor experimental robotics while being one to two orders of magnitude cheaper than comparable commercial systems.