Performance of a Calibrated High Altitude Geolocation System with a Ground-based Reference Signal

The performance of radio frequency (RF) emitter geolocation systems is often dominated by the presence of system biases ̶ related to the collectors, to the receivers, to the emitter-collector environment path, to the terrain, and to emitter motion. In two recent papers (Lerner in CEAS J, May and Nov 2024), the author developed analytical tools to quantify the performance of geolocation systems from low-altitude drones and high-altitude (geosynchronous) collectors. This note applies those tools and models to a bias calibration approach, using a reference emitter with characteristics similar to the RF signals of interest (SOIs), and demonstrates that the impact of collector- and receiver-related biases can be reduced to a level approaching the measurement noise, while providing a precise estimate of geolocation uncertainty. Performance is insensitive to the location of the reference emitter relative to the SOI, and to time delays in the collection of data from the two RF signals.