This chapter describes the guidelines for the realization of a cooperative locator for the navigation of highly automated mobile platforms, based on a robust decentralized architecture with a Bayesian measurement method. The cooperative locator can perform a complete tracking algorithm, in which the velocity and acceleration of the acting nodes are estimated together with the position; furthermore, the collaborative DGNSS and DD techniques can be implemented to increase the accuracy of the measurements. In addition, the cooperative locator must be designed to be robust to uncertainty in the knowledge of noise variance, NLOS propagation, imperfect synchronization and interference.