GeoMax Zoom 30 series - Calibrating Line-of-Sight and Vertical Index Error

Calibration Zoom | 179
11.3 Calibrating Line-of-Sight and Vertical Index Error
Line-of-sight
error
The line-of-sight error, or horizontal collimation error is the deviation from the
perpendicular between the tilting axis and the line of sight. The effect of the
line-of-sight error to the horizontal direction increases with the vertical angle.
Vertical index
error
The vertical circle should read exactly 90° (100 gon) when the line of sight is
horizontal. Any deviation from this figure is termed vertical index error. This is
a constant error that affects all vertical angle readings.
a) Tilting axis
b) Line perpendicular to tilting axis
c) Horizontal collimation, or line-of-sight, error
d) Line-of-sight
a
b
d
c
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