Evaluation of Signal in Space Error Bounds to Support Aviation Integrity

One of the intended purposes of recently proposed Global Navigation Satellite System (GNSS) signals is the provision of high integrity positioning sufficient for use in aviation. Caution is required, as the integrity requirements for aviation, particularly precision approach, are very strict. There must be less than a one in ten million chance of providing misleading information to the pilot. Further, each individual nation is responsible for approving equipment and procedures in their sovereign airspace. In order to make use of signals over which they have no control, aviation authorities must have a clear understanding of the commitments and capabilities of these new signals. This paper proposes equations to combine information from the satellites together with other error bounds to form appropriate upper bounds on the users’ position estimates. The bounds are matched to proposed data monitoring criteria that ensure consistency between what has been observed and what is assumed by the bounding equations.