Читать книгу Global Navigation Satellite Systems, Inertial Navigation, and Integration - Mohinder S. Grewal - Страница 151

In the 1970s, before GPS became a reality, the US Department of Defense established the following categories of INS performance:

High accuracy systems have free inertial CEP rates in the order of 0.1 nautical miles per hour ( m/h) or better.

Medium accuracy systems have free inertial CEP rates in the order of 1 nautical mile per hour ( km/h). This was the level of accuracy deemed sufficient for most military and commercial aircraft [11].

Low accuracy systems have free inertial CEP rates in the order of 10 nautical miles per hour ( km/h) or worse. Sometimes called tactical grade INS performance, this range covered requirements for many short‐range standoff weapons such as guided artillery or tactical missiles.