System and method for protecting against spoofed a-gnss measurement data

A system for detecting one or more forged satellite measurements transmitted from a wireless device, comprising:

• (a) a transmitter for transmitting information to a wireless device, the information including a request that the wireless device provide a portion of a navigation data message from one or more satellites to the system;
• (b) a receiver for receiving one or more satellite measurements and the portion of the navigation data message from the wireless device;
• (c) circuitry for determining the navigation data message as a function of information from a reference network;
• and
• (d) circuitry for comparing the determined navigation data message with the received navigation data message portion to thereby determine whether any of the one or more satellite measurements have been forged.

A method for determining the estimated location of a wireless device when the device transmits one or more forged satellite measurements to a location determining system, comprising the steps of

• (a) sending a request to a wireless device to provide a portion of a navigation data message from one or more satellites to a location determining system;
• (b) receiving one or more satellite measurements and the portion of the navigation data message from the wireless device;
• (c) comparing the received navigation data message portion to an assembled navigation data message to thereby determine whether any of the one or more satellite measurements have been forged;
• and
• (d) estimating a location of the wireless device without the one or more forged satellite measurements.