Accession Number : ADD012961

Title :   Method for Determining the Orientation of a Moving Platform.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON DC

Personal Author(s) : Evans,Alan G

Report Date : 08 Jul 1986

Pagination or Media Count : 10

Abstract : This patent discloses an improved method for continuously determining the orientation of a moving user platform at a selected time fix. A Global Positioning System (GPS) is used to carry out the method and is made up of a plurality of twenty four (24) earth-orbiting satellites wherein each satellite continuously transmits a pair of distinctively encoded RF signals. The GPS system is also provided with a computerized GPS receiver apparatus for use on a moving platform. The receiver apparatus is generally comprised of a rotatable antenna, a single channel multi-track geodetic receiver, a receiver microprocessor, and an orientation computer with a display. The receiver processor selects an optimum group of four satellites to be tracked. The orientation computer during antenna rotation selects a series of four equidistant points about the antenna perihery for receiving signals from each tracked satellite. The signals are transformed by the computer so as to provide a graphic data display output in near real time of the biased range (Doppler phase measurement) of each optimum-tracked satellite in relation to the moving platform.

Descriptors :   *DOPPLER SYSTEMS, *PHASE MEASUREMENT, *GLOBAL POSITIONING SYSTEM, *ORIENTATION(DIRECTION), *PROCESSING EQUIPMENT, *MICROPROCESSORS, *RECEIVERS, *ROTATING ANTENNAS, *TRACKING, ROTATION, CODING, RADIOFREQUENCY PULSES, SIGNALS, MOTION, PLATFORMS, REAL TIME, BIAS, ARTIFICIAL SATELLITES, EARTH ORBITS, DATA DISPLAYS, GRAPHICS, OUTPUT, USER NEEDS, OPTIMIZATION, COMPUTERS, POSITION FINDING, TIME, ARTIFICIAL SATELLITES

Subject Categories : Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE