Military GPS is protected by which code to prevent spoofing?

Military GPS utilizes the Precise Positioning Service (PPS) code, which is designed specifically to provide higher accuracy and resistance to interference and spoofing compared to civilian GPS signals. This advanced service includes various authentication measures and cryptographic techniques that enhance the reliability of the signal, ensuring that military operations have access to precise and secure positioning data.

The PPS code is accessible only to authorized users, such as the military and certain government entities, which adds an additional layer of security against potential spoofing threats. This is crucial for operations requiring highly accurate positioning information and resilience against malicious activities, which cannot be guaranteed with the civilian services.

In contrast, other codes like the Regular Service Code and the Selective Availability Code do not offer the same level of protection. The Regular Service Code is intended for general civilian use, while Selective Availability—a feature that was previously used to intentionally degrade the accuracy of civilian GPS signals—has been turned off since 2000. Lastly, SPS refers to Standard Positioning Service, which is the civilian equivalent of GPS and lacks the robust security features of PPS.