Patent ID: 6501424
Filing Date: 2002-12-31
Classification: G01S

Abstract:
A system comprising:an airborne positioning receiver, for receiving positioning signals from a plurality of positioning transmitters and generating a position determination in response thereto; an airborne HF data receiver, coupled to said airborne positioning receiver; said HF data receiver providing a series of signals responsive to a plurality of broadcast messages which relate to said plurality of positioning transmitters, said plurality of broadcast messages being transmitted from a plurality of terrestrial HF transmitters, in accordance with a predetermined multiplexing scheme; and, a processor which uses information relating to said predetermined multiplexing scheme; wherein the predetermined multiplexing scheme includes a reception of the plurality of broadcast messages from the plurality of terrestrial HF transmitters in a predetermined reception sequence on each of a plurality of frequencies, and further wherein the predetermined reception sequence of terrestrial HF transmitters on one of the plurality of frequencies, over a predetermined time, is different from the predetermined reception sequence of terrestrial HF transmitters on others of the plurality of frequencies over the predetermined time.