How SPOT works?

SPOT products transmit short 1.5 second one-way messages on either 1611.25 MHz in North America and portions of Central America or on 1616.25 MHz throughout the rest of the world.  These frequencies are just above the GPS L1 frequency (1575.42 MHz) used by many aircraft navigation systems.  When the SPOT product transmits, there is the possibility of interference even though both the SPOT device and the aircraft navigation/communication systems meet all FCC regulatory requirements for interference.