Itt Manufacturing Enterprises, Inc.

The Singer Company

Itt Corporation

Exelis Inc.

Peter M Brodie

Laurence J Doyle

Dennis D McCrady

James Monroe Clark

Gene L Cangiani

Harris C Rawicz

Edwin George Solov

James M Clark

Dennis Mccrady

A transmitter employing a cryptographic algorithm and key generates and transmits a staggered pulse signal that includes a plurality of high-power pulses that are part of a pseudonoise (PN) code. The high-power pulses are separated by a group of low-power chips and the time interval between the high-power pulses is varied according to the cryptographic algorithm and key. A receiver, employing a corresponding cryptographic algorithm and key receives the signal and correlates it with a locally generated code that is modified according to the cryptographic algorithm and key to detect the phase of the received PN code. The receiver also can include a matched filter configured according to the cryptographic algorithm and key to detect the sequence of high-power pulses in the received signal.

Staggered pulse acquisition method and apparatus

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.

Apparatus and method for autonavigation with one or more orbiting

A self-contained, strapped down guidance system combining all axes, all attitude navigation having two wide angle, two-degree-of-freedom gyros which provide attitude angle and angular rate signals along three axes. Accelerometer means provide signals representative of the acceleration along three orthogonally displaced independent axes. A first transformation matrix connected to the attitude angle output of the gyros and to the accelerometers transforms the gyro and accelerometer signals from body coordinates to gyro coordinates. A second transformation matrix connected to the output of the gyros, transforms the gyro coordinates into navigation coordinates. In order to perform navigational computations, computing means compute a transformation from gyro momentum vector (referenced to coordinate frame) to a navigational coordinate frame such as a locally vertical frame wherein the Z axis is always along the local vertical direction.

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Oakland, NJ, United States of America

Peter M Brodie