Raytheon Company

Timothy Schempp

Gregory Sechong Um

Thomas L McKendree

Robert M Fries

Arthur Leonard Rubin

Mark Wayne Biggs

A system and method are provided for delivering orbit and clock corrections for Global Navigation Satellite Systems (GNSS) having: (1) reduced orbit and clock discontinuities when changes in ephemeris message from a satellite occur; (2) reduced quantization error by quantifying quantization error by fitting data within the constraints of the output message to prevent broadcast of large errors; and (3) reduced potential errors caused by old but active data.

Method for the generation of satellite clock and orbit corrections for global navigation satellite systems (GNSS)

A method and apparatus for directly estimating depleted ionosphere delay in a GPS receiver and using the estimate for improved navigation precision in satellite based augmentation systems.

Single frequency user ionosphere system and technique

Mechanisms and techniques provide a system to evaluate operational integrity of a data processing system such as an area augmentation system by obtaining at least one set of distribution data related to information processed by the data processing system. The set(s) of distribution data can include corrections information and integrity bounds information related to the corrections information. The system applies a moment generating function to the set of distribution data to produce a moment bounded distribution data result and compares the moment bounded distribution data result to an integrity limit to determine if the data processing system operates within an acceptable integrity threshold. The system can be used in real-time or non-real time with sets of distribution data that are non-Gaussian, non-symmetric and/or non-unimodal.

Methods and apparatus for evaluating operational integrity of a data processing system using moment bounding

Methods and apparatus for providing integrity alert information include embedding the integrity alert message in a longer message stream that is broadcast to a receiver in order to meet a predetermined time to alert. In one particular embodiment, the receiver is a GPS receiver, the longer message is a navigation signal, and the integrity alert message is a 50 bit word containing an updated user range accuracy index. Advanced GPS users recognize the embedded integrity alert message by its message ID, pass a parity check on the integrity alert message and use the updated user range accuracy index in subsequent signal processing. Legacy GPS users fail parity on the integrity alert message and discard the message. The impact on legacy users is negligible since the infrequent alerts will only occasionally cause data to be discarded.

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Anaheim, CA, United States of America

Timothy Schempp