Abstract: A method for determining the geolocation of an object such as a vehicle traversing the earth's surface or airborne thereabove includes employing a device which is capable of operating autonomously to transmit signals to a selected low earth orbit (LEO) satellite for relay to a receiving station whose position is known, identifying the device and its geolocation, speed, altitude and/or heading. The device includes a microcomputer which operates a Global Positioning System (GPS) receiver for receiving GPS signals to identify the device geolocation and the precise time. A nonvolatile memory on board the device stores LEO satellite ephemeris data, satellite operational and message formatting parameters, LEO satellite visibility footprint data and visibility contour information for the device caused by obstacles which are permanently or temporarily in proximity to the device during deployment and which block transmission of signals between the device and the LEO satellite, depending on relative positions.

Abstract: A system and method for transmitting information to a receiving station via one or more Low Earth Orbit (LEO) satellites includes a device which is capable of operating autonomously to transmit signals to a selected LEO satellite for relay to a receiving station identifying the device and its geolocation including longitude and latitude and/or speed, altitude and heading or course. The device includes a microprocessor which operates a Global Positioning System (GPS) receiver for receiving GPS signals to identify its geolocation and precise time. A nonvolatile memory onboard the device stores LEO satellite ephemeris data, and identification, operational and message formatting information to enable the device to transmit information including voice, data and/or the geolocation of the device to a selected LEO satellite, such as the next visible LEO satellite, for relay to a receiving station.