Eride,. Inc.

Other

Seiko Epson Corporation

Furuno Electric Company Limited

Kenneth U Victa

Paul W McBurney

William J Morrison

Justin A Vandegrift

Shahram Rezaei

Frederic Vaucher

Clark W Rasmussen

An improved extended ephemeris navigation receiver includes a fully autonomous satellite navigation receiver for receiving microwave transmissions from orbiting navigation system satellites, and able to demodulate navigation messages that include the ephemerides for those navigation system satellites. The improvements include a force model of the accelerations acting on a particular satellite vehicle, and are exclusive to the receiver. A single observation of the ephemeris for each SV is input and propagated days into the future by integrating each SV's orbital position with its corresponding force model. The fully autonomous satellite navigation receiver thereafter has available to it extended ephemeris predictions that can be used as substitutes when said navigation messages from the respective SV cannot otherwise be immediately obtained and demodulated.

Satellite navigation receivers with self-provided future ephemeris and clock predictions

A roving extended range high sensitivity satellite positioning system receiver provides position fixes in adverse signal conditions as low as minus 150 dbm and with as few as three satellites by measuring the bit phase of the navData message and the codephase, and finding a simultaneous solution. Previous position fixes that were obtained in the vicinity by earlier rovers are deposited in an indexed database for consultation. A cellular phone system can be used to simply communicate the current identity codes and their database entries.

Extended range high sensitivity SPS positioning receiver

A roving extended range high sensitivity satellite positioning system receiver provides position fixes in adverse signal conditions as low as minus 150 dbm and with as few as three satellites by measuring the bit phase of the navData message and the codephase, and finding a simultaneous solution. Previous position fixes that were obtained in the vicinity by earlier rovers are deposited in an indexed database for consultation. A cellular phone system can be used to communicate the vicinity ID's and their database entries.

A thin-client navigation-satellite receiver network collects GPS pseudorange measurements and communicates them from many independent clients on a computer network to a server. The server computes the respective navigation solutions and sends the results back to each client. A client manager at the server includes a client-request handler that interfaces with the network and collects the discrete requests from each of the clients. An assembler builds complete data sets from one to five seconds worth of data gathered by the client-request handler and spins each ready-to-go job to a bank of navigation servers. A session manager coordinates the inputs-and-results communication on the network and sends its outputs to a client responder.

Thin-client

A navigation-satellite receiver depends on a network server to occasionally provide key pieces of information needed during its initialization. The navigation-satellite receiver critically maintains its position uncertainty, sigmaPos, to under 150-km. Therefore, at least every five minutes, the navigation-satellite receiver uses a network connection to download all the ephemeris information for all the operational SV's. The power-off time uncertainty, sigmaTime, is kept under one millisecond by running a real-time clock with a software-compensated crystal oscillator reference. Such information is instantly available at power-up to reduce the time necessary to produce a first fix when receiver signal levels are under &minus;150 dbm even for the strongest SV.

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San Francisco, CA, United States of America

Kenneth U Victa