Patent ID: 9223026
Filing Date: 2015-12-29
Classification: G01S

Abstract:
1. A GNSS reference apparatus, including: a vector error generator to generate a sequence of reference erroneous positions by combining one or more sequences of keyed intentional errors, the keyed intentional error sequences made confidential with one or more confidential error keys, respectively; and a reference data server to issue GNSS position-determination reference data based on the reference erroneous positions to enable GNSS position determination where the keyed intentional errors for at least one of the confidential sequences are reversible with confidential access to a corresponding at least one of the confidential error keys wherein, the vector error generator includes a seed generator to combine a non-confidential frame number with a particular one of the confidential error keys to generate a particular one of the keyed intentional error sequences as a pseudo-random sequence, where the pseudo-random sequence is reproducible at a GNSS rover in data frames with the non-confidential frame number and the particular confidential error key.