Topcon GTS-710 Series - 11 折射與地球曲率之改正; 距離化算公式

11 CORRECTION FOR REFRACTION AND EARTH CURVATURE
11-70
11 折射與地球曲率之改正
The instrument measures distance, taking into account correction for refraction and earth
curvature.
Note :
If the telescope is positioned within
±9° from the nadir or zenith, no measurement
will result even if the correction function for refraction and earth curvature
works.The display shows "W/C OVER".
11.1 距離化算公式
Distance Calculation Formula; with correction for refraction and earth curvature taken into
account. Follow the Formula below for converting horizontal and vertical distances.
Horizontal distance D=AC(
α) or BE(β)
Vertical distance Z =BC(
α) or EA(β)
D=L{cos
α-(2 θ-γ)sinα}
Z=L{sin
α-( θ-γ)cosα}
θ=Lxcosα/2R.............. Earth curvature
correcting item
γ=KxLcosα/2R............ Atmospheric refraction
correcting item
K=0.14 or 0.2............. Coefficient of refraction
R=6372km................. Radius of earth
α ( or β) .................... Altitude angle
L ................................ Slope distance
z The conversion formula for horizontal and vertical distances is as follows when
correction for refraction and earth curvature is not applied.
D=Lxcos
α
Z=Lxsin
α
Note : The coefficient of the instrument has been set at 0.14 before shipment (K=0.14).
if the "K" value is to be changed, refer to Chapter 7 "PARAMETERS SETTING
MODE".
Radius of esrth
R = 6372 Km
E
D
C
B
A
-Z
20
20
0
β
α
θ
2θ