Raytheon Company

Robert M Fries

Shuwu Wu

James Joseph Richardson

Thomas L McKendree

Timothy Schempp

Stephen R Peck

Robert C Saunders

Peter D Shloss

Technology for determining a point-to-point separation between a first ship (e.g., guide ship) and a second ship (e.g., following ship) is disclosed. One approach can include maritime autonomous station keeping (MASK) interactive device comprising a communication module and a processor. The communication module can be configured to receive a following ship reference point (SRP) generated by at least one differential global positioning system (DGPS) receiver on a following ship relative to a guide SRP generated by at least one DGPS receiver on a guide ship. The processor can be configured to generate a plurality of fixed following reference edge points (REPs) relative to the following SRP representing a following ship hull, generate a plurality of fixed guide REPs relative to the guide SRP representing a guide ship hull, and monitor a plurality of distances between the plurality of following REPs and the plurality of guide REPs.

Maritime autonomous station keeping (MASK)

Methods and apparatus for providing high integrity probability of connect fix (PCF) in GPS navigation applications, such as precision approach and landing and airborne refueling. In an exemplary embodiment, an enlarged pull in region is used to compute protection levels. In an exemplary embodiment, geometric extra-redundancy is used to enhance PCF and PAF (probability of almost fixed). In an exemplary embodiment, geometric extra-redundancy almost fixed solutions provide superior accuracy and integrity for GPS navigation applications.

Methods and apparatus for geometry extra-redundant almost fixed solutions

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.

Methods and apparatus for satellite integrity messaging

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Irvine, CA, United States of America

Robert M Fries