System for detecting signal spoofing by monitoring for abnormal divergence in pseudorange values

A method of determining if received satellite signals are being spoofed, the method comprising:

• determining raw pseudorange values from received satellite signals;
• communicating the raw pseudorange values to a first path and a second path;
• smoothing the raw pseudorange values with a filter in at least one of the first and second paths;
• and
• determining if spoofing is occurring based on a detected divergence between outputs in the first and second paths.

A method of operating a vehicle with a system for detecting signal spoofing by monitoring for abnormal divergence in pseudorange values, the method comprising:

• receiving satellite signals with at least one receiver;
• determining raw pseudorange values from the received satellite signals;
• applying a first filter to the determined raw pseudorange values to generate first smoothed pseudorange values;
• applying a second filter to the determined raw pseudorange values to generate second smoothed pseudorange values, the second filter having different filter characteristics than the first filter;
• determining if spoofing is occurring based on a detected divergence between the first smoothed pseudorange values and the second smoothed pseudorange values;
• and
• controlling a navigating system of the vehicle based in part on determined spoofing.