A novel Multi-Receiver Vector Tracking (MRVT) architecture for the joint tracking of multiple GPS receivers to determine the reference position and attitude of a rigid body is presented. The reduction in overall search space, from the state variables of each individual receiver to a single reference position on the rigid body and the attitude of the rigid body, offers increased information redundancy which brings about increased robustness to signal attenuation and multipath. The MRVT architecture is implemented using a Software Defined Radio (SDR) written in Python with an Object-Oriented Programming (OOP) approach that allows easy initialization, modification and extension of the receivers and the multiple receiver network. It also allows for flexible sharing of information at the signal, measurement, data and coordinate levels. Finally, experiments were conducted on a road vehicle for performance evaluation.