Patent ID: 9217792
Filing Date: 2015-12-22
Classification: G01S

Abstract:
1. A GNSS In-Band Authentication system comprising: a GNSS ground segment; a GNSS user segment comprising at least one GNSS receiver; and a GNSS space segment comprising a GNSS satellite constellation transmitting ephemeris data in a C/A message on the L1 band, wherein one or more GNSS satellites are designated authentication support (DAS) satellites and transmit a special status signal, intentionally corrupted ephemeris data and an intentionally corrupted C/A signal including a pseudo-random error on the L1 band; wherein the at least one GNSS receiver is configured to calculate its own position using GNSS satellites in the GNSS satellite constellation other than the one or more DAS satellites, determine authentication ranges to the one or more DAS satellites within a field of view of a GNSS receiver, determine the GNSS time of the position, and transmit a position report comprising at least its calculated own position, position time, and the determined authentication range for the one or more DAS satellites within a field of view of the GNSS receiver to a surveillance system, and wherein the surveillance system is configured to receive the position report, compute verification ranges to the one or more DAS satellites using the reported position of the at least one GNSS receiver, uncorrupted ephemeris data for each of the one or more DAS satellites, and position time, compare the computed verification ranges to the determined authentication ranges in the received position report, and verify the reported position of the at least one GNSS receiver when the computed verification ranges and the determined authentication ranges in the received position report are within a predetermined tolerance range.