Conventional Gyroscopic Survey Tools
The heart of a conventional gyroscope is the gyro wheel, which spins at high speed symmetrically about an axis. A perfect gyro wheel will maintain its orientation in inertial space for as long as no external forces act on it to alter the direction of the spin axis.
In conventional gyro directional survey tools this principle is used to measure the change in orientation of the tool, when following the wellpath, relative to the original spin axis orientation at the start of the survey. Consequently the conventional gyro needs aligning of the initial . . .