The measurement of the azimuth angle of the orientation side with a gyro theodolite, referred to as gyro orientation. Due to manufacturing defects of the rack-mounted gyro theodolite, the gyro axis swing balance position (called the gyro meridian direction) observed through the eyepieces does not coincide with the true meridian of the passing station, so it can only measure the gyro position based on the gyro meridian. angle. The azimuth angle of a certain side of the gyro is obtained by measuring the difference between the value of the meridian direction of the gyro and the value of a certain side. The difference between the azimuth of the gyro and the true azimuth of a certain side (that is, the dihedral angle between the gyro meridian and the true meridian) is called the instrument constant. The instrument constant must be measured for each orientation; the gyro azimuth angle is measured on the orientation side, and the coordinate azimuth angle of the orientation side is obtained through calculation.
The gyro theodolite orientation can be used to: orient a certain level underground; measure the coordinate azimuth of a wire side at intervals in the theodolite wire, so that the wire becomes a direction attached wire, which can control the accumulation of angle measurement errors; mines, tunnels, etc. Orientation of large-scale underground engineering survey; Orientation of survey in shaded areas.
When the vertical shaft directional measurement needs to transfer the coordinates, a steel wire perpendicular is suspended in the wellbore, and the coordinates of the steel wire are measured on the ground; the wire is measured between the wire perpendicular and the gyro orientation edge, and the wire points are calculated according to the wire calculation method coordinate of.
Field observation of gyro orientation is mainly to measure the azimuth angle of a certain side of the gyro. In order to obtain the coordinate azimuth of a certain traverse side in the well, a certain orientation procedure must be followed.