Portable personal navigation tracking system

摘要: A data/voice modem embodiment of the present invention comprises an asynchronous-to-synchronous data converter for interface with a GPS receiver, minimum space keyed modem, and continuous tone controlled sub-audible squelch controller that modulates radio transceiver discrete such both voice may share common channel. The periodically keys-up transmitter through its transmits packet information contains user position velocity obtained adds identification code time tag. Incoming message packets from are sent other similarly equipped mobile units used to supply individual network member absolute positions velocities, this is stored by number as goal or waypoint equivalents. As such, distance-to-goal, estimated-time-of-arrival velocity-made-good estimates made available on target track screen included in respective receiver.