Comparing Angles, Bearings and Azimuths

1
Comparing Angles, Bearings and Azimuths

• Given a bearing of N324530W, compute the
  equivalent azimuth.

324530
NW
360 - 324530 3271430
Azimuth
Bearing
2. Given an azimuth of 1221236, compute the
equivalent bearing.
1221236
180 - 1221236 524724
Azimuth
Bearing
2
ANGULAR OBSERVATIONS AND DISTANCES
THE QUALITY OF AN ANGULAR OBSERVATION DEPENDS TO
A LARGE DEGREE ON THE PRECISION WITH WHICH AN
OBJECT CAN BE BISECTED WHICH IN TURN DEPENDS ON
THE DISTANCE BETWEEN THE TELESCOPE AND THE OBJECT
A pointing error of 1cm over 10m corresponds to
an angle of 326
C
1000 m
A bisecting error of 1cm over 1000m corresponds
to an angle of 02
10 m
B
An angular error of 3 26 will amount to a
linear error of 1.00 m over a distance of 1000 m
(B-C)
A
Rule of Thumb 1 error over 100m gives 3cm
linear error 1 error over 100ft gives
0.03 ft linear error
3
VERTICAL ANGLES
0
0
500
90
270
270
90
3100
180
180
Direct
Reverse
With no index error ZD ZR 3600 500 3100
Index error occurs when the 00 is not exactly
vertical
4
Index Error
Index Error
Index Error
0
0
500
270
90
90
270
3100
180
ZD 540 50 10 ZR 3050 10 20 ? 3600
00 30
180
Reverse
Direct
Index Error b 30/2 15
Corrected ZD 540 50 10 15 540 49
55 ZR 3050 10 20 15 3050 10
05 ? 3600 00 00
pp. 206-208