Menu Key
5
Pulse Laser Station NPL-302 Series Instruction Manual
137
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 dist
VA
Vertical angle
R
e
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 NPL-302 Series
Страница 1: ...H163E 05 10 TF 9 Pulse Laser Station NPL 302 Series Instruction Manual NPL 332 NPL 352 NPL 362 ...
Страница 4: ......
Страница 5: ...Safety 1 In this chapter Q Introduction Q Laser Safety Q Warnings and Cautions ...
Страница 12: ...Safety xii Pulse Laser Station NPL 302 Series Instruction Manual ...
Страница 28: ...1 Introduction 8 Pulse Laser Station NPL 302 Series Instruction Manual ...
Страница 46: ...2 Preparation 26 Pulse Laser Station NPL 302 Series Instruction Manual ...
Страница 82: ...3 Getting Started 62 Pulse Laser Station NPL 302 Series Instruction Manual ...
Страница 188: ...5 Menu Key 168 Pulse Laser Station NPL 302 Series Instruction Manual ...
Страница 196: ...6 Checking and Adjustment 176 Pulse Laser Station NPL 302 Series Instruction Manual ...
Страница 208: ...8 System Diagrams 188 Pulse Laser Station NPL 302 Series Instruction Manual ...