System and method for GNSS in-band authenticated position determination

摘要

The present invention provides a system and method for determining the authenticity of reported positions of GNSS receivers, such as aircraft equipped with GPS positioning devices, and provides an in-band verification capability for GNSS positions by tasking one or more GNSS satellites as designated authentication support (DAS) satellites that transmit corrupted ephemeris data in a pseudo-random error corrupted C/A signal on the L1 band, and the GNSS receivers determine authentication ranges to the DAS satellites and transmit the DAS authentication ranges as part of their position report. The surveillance system can verify the authenticity by comparing the transmitted authentication ranges to true authentication ranges determined using actual ephemeris data and the known C/A code pseudo-random error for the DAS satellites.

主权项

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.