In terminal mode, GPS position accuracy is closest to which value?

In terminal mode, GPS position accuracy is closest to which value?

• A. 0.5 NM
• B. 1 NM
• C. 2 NM
• D. 5 NM

Answer: (B)

In the terminal phase, GPS position accuracy is determined by how the satellite geometry and receiver error budget perform in a relatively confined airspace. For standard GPS without augmentation, the horizontal accuracy you can typically expect in the terminal area is about one nautical mile (with 95% probability). This means the position reported by the GPS is usually within roughly one mile of your true location most of the time when you’re in terminal airspace. This level of accuracy is more precise than en route, where errors can be larger, and not as tight as some approach-area scenarios that can be improved further with augmentation systems. If a receiver is using augmentation like WAAS, accuracy can improve to about half a mile or better, but the common, unaugmented terminal figure is around one nautical mile.

In the terminal phase, GPS position accuracy is determined by how the satellite geometry and receiver error budget perform in a relatively confined airspace. For standard GPS without augmentation, the horizontal accuracy you can typically expect in the terminal area is about one nautical mile (with 95% probability). This means the position reported by the GPS is usually within roughly one mile of your true location most of the time when you’re in terminal airspace.

This level of accuracy is more precise than en route, where errors can be larger, and not as tight as some approach-area scenarios that can be improved further with augmentation systems. If a receiver is using augmentation like WAAS, accuracy can improve to about half a mile or better, but the common, unaugmented terminal figure is around one nautical mile.