Abstract

A navigation system, incorporating a unique method for detecting failures and determining an accuracy or error bound, has a receiver for receiving signals from several remote transmitters and a processor for determining a position solution from the signals. The processor, preferably employing Kalman filtering techniques, also determines several position subsolutions from subsets of the signals. The processor then computes covariance-based solution separation parameters based on statistical worst-case differences, or separations, between the position solution and the subsolutions. Similarly, the processor also computes error parameters defining statistical worst-case errors in each position subsolution. With the solution separation and the subsolution error parameters, the processor determines an error bound for the position solution. The processor also uses the separation parameters as detection thresholds for detecting transmitter failures. In one embodiment, the processor incorporates inertial reference data into the solutions and ultimately into the error bound calculation, thereby improving the ability of the navigation system to monitor its own accuracy, or integrity.

Other References

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