In the latest release of our SatGen GNSS simulation software, the anti-spoofing flag transmitted in the GPS L1C/A navigation message is now automatically set depending on the selected signals. This feature has been developed as some receiver models are unable to return a position if the anti-spoofing flag is OFF.
- ON: When L1C/A is simulated, but neither L1P nor L2P, the anti-spoofing flag is ON.
This tells the receiver that the encrypted Y-Code is transmitted instead of the public P-Code on L1 and L2. Although SatGen does not simulate the Y-Code, the anti-spoofing flag is set to ON because some receivers refuse to work if that flag is OFF.
- OFF: When L1C/A is simulated together with any of L1P and L2P signals, the anti-spoofing flag is OFF.
This tells the receiver that the public P-Code is transmitted on L1 and L2.
The full release history can be found here.