What does the PPS GPS design specification dictate in terms of accuracy?

• A. 3 meters
• B. 6 meters
• C. 9 meters
• D. 12 meters

Answer: (B)

The main concept being tested is the accuracy target defined by the PPS GPS design specification. The specification sets a horizontal positioning accuracy target of about six meters for an authorized user, taking into account real-world factors like receiver noise, atmospheric delays, multipath, satellite geometry, and clock errors. This six-meter target represents the expected performance the PPS is designed to guarantee under typical conditions, balancing precision with reliability and integrity.

Choosing a value like six meters reflects the spec’s intent: tighter accuracy (for example, three meters) would require conditions or equipment beyond what the PPS is guaranteed to provide in all typical scenarios, while looser values (nine or twelve meters) would not meet the guaranteed performance the design aims to deliver.