This paper reports on an underwater cooperative localization algorithm for faulty low-bandwidth communication channels based on a factor graph estimation framework. Vehicles measure the one-way-travel-time (OWTT) of acoustic broadcasts to obtain a relative range observation to the transmitting vehicle. We present a method to robustly share locally observed sensor data across thenetwork by exploiting odometry factor composition.
Our algorithm calls on approximate marginalization techniques to compute a compact set of informative factors that enable local navigation data to be shared efficiently. We provide results from a real-time implementation of our algorithm using two autonomous underwater vehicles and a surface vehicle.