POA Power On Arrival (POA) is a geolocation technique which uses the differences in power at receivers to pinpoint location using a minimum of three receivers. POA is particularly useful for short range applications such as in buildings and RFeye SyncLinc can further improve in-building performance by time-synchronizing receivers very accurately. POA is a simple geolocation technique that uses synchronous frequency domain captures to determine and compare the instantaneous relative power of a signal at different receiver locations. Given the rapid drop-off in received signal power over distance from a transmitter, the POA technique is optimal for relatively short-range geolocation such as in-building monitoring, where the amplitude comparison yields sufficient differences. POA requires three or more monitoring receiver points to provide geolocation probability to a point. Increasing the density of receiver points significantly improves the quality of the geolocation. POA is effective with any RF transmission type, from unmodulated carrier wave signals to narrow-band or short-burst pulsed transmissions, since the technique relies only on received RF power. POA requires accurate timing synchronisation between receivers. Although GPS synchronisation is viable, it is typically not practical or secure for in-building applications. High performance wired timing synchronisation systems such as RFeye SyncLinc are therefore used in-building.