1. Definitions and principles

Definitions

• A gyroscope is a device capable of providing a physical reference direction and, correlatively, angular rotation information, in the form of an angular deviation, or whole angle, between 0 and 360, relative to an absolute or "inertial" reference frame.

• A gyrometer is a device capable of providing angular velocity information, relative to an absolute reference frame (i.e. fixed relative to the stars).

• In a number of cases, the same device can operate as a gyroscope or a gyrometer.

Gyroscopic principles

• A gyroscope (angle meter) basically uses the characteristic property of inertiality...