A system and method for determining the geolocation of a signal emitter moving at an unknown velocity by combining signal data of a target detection platform (e.g., a radar system) and signal data collected by two or more moving signal collection platforms (e.g., RF signal receivers). In one embodiment, the target detection platform determines tentative location and velocity of the signal emitter, and the signal collection platforms are configured to perform TDOA and/or FDOA analysis of the collected signal data corresponding to a signal of the signal emitter. In one embodiment, solutions provided from the TDOA and/or FDOA analysis are unbiased by using the tentative velocity of the signal emitter, and the geolocation of the signal emitter is determined by matching the TDOA/FDOA solutions and the detected tentative location.