Abstract: A network comprises a plurality of GPS navigation receivers with two-way radio data communication for communicating the current computed positions of individual mobile units to other mobile units in the network and to stationary dispatch controllers connected in by the public switched telephone network. Ordinary telephone personal pager service is carried out transparently in the network for non-GPS equipped mobile units.

Abstract: A GPS navigation receiver with a data output port for communicating a position estimate frame-by-frame and time codes in SMPTE format. The conventional date and time sentence output of the GPS navigation receiver is combined with a highly-accurate one pulse-per-second (.+-.one microsecond) to form a time-keeping base for the time code output. A data-logger records the position estimates with their corresponding time in time code format frame-by-frame in a database. The recorded position estimates are then used in special-effects post-production to direct the special-effects animation, modeling kinetics, etc., in a composite, final film or video.

Abstract: A combination of a GPS receiver for determining a user's position in terms of latitude and longitude, a database that indexes approximately 53,000 USGS 7.5 minute series topographical quadrangle maps by the latitude and longitude of at least one point on each map, and an interpreter and display that communicates the particular USGS map that represents the user's position together with the ruler dimensions left/right/up/down from a reference point on that map which pinpoints the user's position on the map. The database is stored in the permanent memory of the GPS receiver and the interpreter and display are controller by a microcomputer included in the GPS receiver. The reference points include sixteen intersections on the map of 2.5 minute intervals of latitude and longitude contained in each 7.5 minute series quadrangle.

Abstract: A GPS receiver comprises a data output port for communicating time code information formatted according to standards published by the Society of Motion Picture and Television Engineer (SMPTE). Such time code information is input to independent sound, film and video recorders at a performance event to create tracks on each recording for re-synchronizing the pictures and sounds in post-performance editing.

Abstract: A GPS receiver comprises a data input/output port for communication of datum-less position fixes in an earth-centered, earth-fixed (ECEF) coordinate style to avoid the errors associated with not communicating the datum choice with latitude longitude data communication formats.

Abstract: An embodiment of the present invention comprises a GPS receiver including a conversion table memory index for storing latitude-longitude lookup conversions to standardized map coordinates and scale factors.

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