5
Menu Key
106
Total Station DTM-322 Instruction Manual
Curvature and Refraction correction
Because the surface of the earth is curved, the vertical difference (VD and Z) at the
measurement point, as referenced to the horizontal plane, inevitably includes some
error. This error is called
curvature error
. Also, because the density of the air
surrounding the earth decreases with altitude, light is refracted at different rates at
different altitudes. The error caused by this change in refraction is called
refraction
error
.
HD
Horizontal dist. (before adj.)
HD’
Horizontal dist. (after adj.)
VD
Vertical dist. (before adj.)
VD'
Vertical dist. (after adj.)
SD
Slope distance
VA
Vertical angle
Re
6370 km
k
C&R constant (0.132 or 0.200)
Curvature error (A A
'
)
Refraction error (A A1
'
)
P
A
'
Horizontal
direction
A
O
P
A1
'
A1
A
'
HD'
HD
SD
2
2VA
(
)
sin
2R
e
----------------------------------- 1 k
2
---
–
⎝
⎠
⎛
⎞
–
=
VD'
VD
HD
2
2R
e
----------- 1 k
–
(
)
+
=
Содержание Total Station DTM-322
Страница 1: ...www trimble com Total Station DTM 322 Instruction Manual Version A 1 0 0 Part Number C232E April 2009 ...
Страница 8: ...viii Total Station DTM 322 Instruction Manual ...
Страница 14: ...Contents xiv Total Station DTM 322 Instruction Manual ...
Страница 60: ...3 Getting Started 46 Total Station DTM 322 Instruction Manual ...
Страница 157: ...C H A P T E R 8 Total Station DTM 322 Instruction Manual 143 System Diagrams 8 In this chapter System Components ...
Страница 160: ...8 System Diagrams 146 Total Station DTM 322 Instruction Manual ...
Страница 176: ...9 Communications 162 Total Station DTM 322 Instruction Manual ...