Abstract: An event-based communication strategy for navigation using signals of opportunity (SOPs) in a collaborative radio simultaneous and mapping (CoRSLAM) framework is developed. The following problem is considered. Multiple autonomous vehicles (AVs) with access to global navigation satellite system (GNSS) signals are aiding their on-board inertial navigation systems (INSs) with GNSS pseudoranges. While navigating, AV-mounted receivers draw pseudorange measurements on ambient unknown terrestrial SOPs and collaboratively estimate the SOPs’ states.