Definition:
~ gyroscopes were initially a French specialty (first gyroscope invented by Léon Foucault in 1850s)
~ they can be classed in order of their precision, expressed in terms of drift measured in °/h (degrees per hour)
~ drift is degree of error in fixed direction gyroscope is supposed to provide with regard to stars
~ example drifts 100 °/h "flight control" or "short-range tactical weapons" class to better than 0.0001°/h : "star in a bottle" class
~ different technologies are implemented for various precision classes and operating constraints of vehicle
~ (can gyroscope be separated from vehicle through gimbal suspension or
~ can it/must it be part of vehicle structure – strap-down mounting )
~ these include:
~ * Floating gyroscopes: the beginnings of the "great inertia" of the 1950s
~ * Dynamically tuned wheel gyroscopes – platform or strap-down
~ * Vibrating gyroscopes (tuning-fork/quapason; hemispherical resonator gyroscope) – strap-down
~ hemispherical resonator gyroscope, in particular, is set to offer significant cost reductions for equal performance,
~ including true "inertial" capacity
~ * Ring-laser gyros, the most popular "strap-down" gyroscope of the decade
~ * Fiber optic gyros in "fly-by-wire" or "short-range tactical weapons" class
~ * Electric suspension (electrostatic) gyroscopes: "star in a bottle" class

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