Itt Manufacturing Enterprises, Inc.

Itt Corporation

Laurence J Doyle

Peter M Brodie

Harris C Rawicz

The present invention is directed toward a navigation system and method for a high orbit spacecraft, which passively utilizes UHF signals carrying intersatellite ranging data transmitted by a constellation of satellites that travel in lower orbits around a celestial sphere. The navigation system enables the high orbit spacecraft to self locate its position relative to an earth centered coordinate frame and comprises a receiver for receiving the UHF signal, carrying the intersatellite ranging data and a Kalman or optimum filter coupled to the receiver for processing the ranging data received by the receiver and generating and updating spacecraft position data.

Technique for the use of GPS for high orbiting satellites

The present invention is directed toward a navigation system and method for a high orbit spacecraft, which passively utilizes UHF signals carrying intersatellite ranging data transmitted by a constellation of satellites that travel in lower orbits around a celestial sphere. The navigation system enables the high orbit spacecraft to self locate its position relative to an earth centered coordinate frame and comprises a receiver for receiving the UHF signals carrying the intersatellite ranging data and a Kalman or optimum filter coupled to the receiver for processing the ranging data received by the receiver and generating and updating spacecraft position data.

A system of making satellite-to-ground range measurements, carrying out communications between a ground station and a constellation of autonavigating satellites, and using these range measurements to improve navigation accuracy is disclosed. The system comprises an anchor that is in a fixed position relative to the earth. The anchor implements a filtering algorithm to arrive at solutions for the satellites' positions based on measured satellite positions and predicted satellite positions. Each time a new measurement is received by the anchor an update is generated. In this manner the system is capable of updating satellite positions at a greater rate than similar prior art systems, thereby, decreasing the transient response associated with satellite delta-v maneuvers and decreasing the quantity of data that must be exchanged by the anchor and the satellites.

Growing community of inventors

Hazlet, NJ, United States of America

Laurence J Doyle