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3.7 The Correction of the Atmospheric refraction and
the Earth Curvature
When measuring horizontal distance and elevation, our
instrument corrects the atmospheric refraction and the earth curvature
automatically.
The formulas of two corrections about our instrument are as
followed:
Corrected Horizontal Distance :
D=S×[cosα+sinα×S×cosα(K-2) / 2Re]
Corrected Elevation :
H=S×[sinα+cosα×S×cosα(1-K) / 2Re]
If the Atmospheric Refraction and the earth curvature are not
corrected, the formula for calculating horizontal distance and
elevation are as followed:
D=S×cosα
H=S×sinα
In the formula:
K=0.14----------- Atmospheric refraction coefficient (can be
selected according to actual)
Re=6370 km---Radius of the earth curvature.
α(or β)-----------------The vertical angle (counted from the
horizon)
S-------------------Slope distance
3.8 Set up the minimum reading of the angle
Refer to the operation ―Menu
→
5.Options
→
3.Other options
→
1.Mini Angle
”
. The interface as shown in picture below:
Mini Angle
[1. 1″ ]
Exit
Enter
2. 5″
3. 10″
3.9 Set up the minimum reading of the distance
Refer to the operation ―Menu
→
5.Options
→
3.Other options
→
F4
→
3.Miniread (dist)
”
. The interface as shown in picture below:
