Raytheon Company

Joseph Chang

Shuwu Wu

Andrew J Thomas

Stephen R Peck

Tyler Thomas

Matt Keti

Jason M Burke

A method for multi-track environmental fault monitoring for aerial platforms includes estimating a normalized squared residual error (NSRE) for each of one or more satellite-receiver tracks over time. The method also includes determining an averaged NSRE for each satellite-receiver track by averaging the NSRE over multiple time windows. The method further includes performing a threshold test on the averaged NSRE to determine a filter state. In addition, the method includes determining whether to apply a scale factor for each satellite-receiver track based on the filter state.

System and method for multi-track environmental fault monitoring for aerial platforms

A method includes repeatedly determining a distance of an aircraft from a landing location. The method also includes, during a first stage in which the aircraft is at least a threshold distance from the landing location, performing iono-free processing during navigation of the aircraft. The method further includes, during a second stage in which the aircraft is less than the threshold distance from the landing location and a velocity of the aircraft is greater than a velocity threshold, performing divergence-free processing during navigation of the aircraft to address possible ionospheric threats. In addition, the method includes, during a third stage in which the aircraft is less than the threshold distance from the landing location and the velocity of the aircraft is less than the velocity threshold, calculating one or more floor values for a Differential Ionospheric Correction (DIC) sigma, and determining a navigation solution to protect against nominal ionospheric conditions.

System and method for mitigating against ionospheric gradient threats for aerial platforms

The concepts, systems and methods described herein are directed towards real time carrier phase monitoring and platform attitude solutions on a moving platform. In an embodiment, highly accurate platform attitude and monitored carrier phases can be determined in a single step and use data screening, error bounds inflation and statistical tests to ensure both inputs and outputs of an attitude solution are self-consistent. The method includes determining a carrier phase error level for each of the satellite-receiver tracks, identifying the satellite-receiver tracks having the carrier phase error level greater than or equal to a carrier phase error threshold, generating an attitude correction using the received data from the one or more satellite-receiver tracks having the carrier phase error level less than the carrier phase error threshold and determining a convergence state of the attitude correction. The carrier phase monitoring may be activated or dis-activated based on the convergence level.

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Orange, CA, United States of America

Joseph Chang