||Conventional total station
||If the position of the equipment fixed rotates or moves parallel three dimensionally due to natural behavior, measuring errors occur at displacement points X, Y and Z, besides the error of the equipment.
Therefore by providing more than four reference points, coordinate compensation to the 3 dimensions of the initial state is made.
|The reference points are usually one or two points.
If the coordinates of fixed point of equipment move three-dimensionally
by natural behavior, compensation by 1-2 reference points
is insufficient and great error may occur in the measured
Therefore it is necessary to install the equipment as close
to unmoving positions as possible.
||The origin point coordinates of equipment are compensated by matrix operation, and measuring displacement at a measuring point 100 m distant can be made with an accuracy of around 1 mm.
At a point 120 m distant,
X=±1.07mm, including mechanical error
Y=±0.31mm, including mechanical error
Z=±1.28mm, including mechanical error
X,Y,Z: ±3.0 mm
(mechanical error) + 2 ppm (distance error)
Distance error : 2 ppm = 21
km10-6= 2 mm
Thus has an error of 5 mm per distance of 1 km.
of output data
||If the coordinate point of the device installation position
moves by natural behavior, compensation of data must be necessary.