ORBCOMM low Earth orbit mobile satellite communication system

Abstract

The ORBCOMM digital data communication and position determination system can provide the United States Armed Forces with two-way on-the move data messaging anywhere in the world. The ORBCOMM system uses a constellation of 36 small spacecraft in low-Earth orbit (LEO) instead of terrestrial fixed site relays or repeaters to provide worldwide geographic coverage. The subscriber communicators (user terminals) are lightweight and pocket-sized. They transmit and receive short digital burst packets, with inherent LPI/LPD.<>