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LECTURE №2

ANGLES, BEARING AND AZIMUTHS

2.1 Introduction
Determining the locations of points and orientations of lines frequently
depends on measurements of angles and directions. In surveying, directions are
given by bearings and azimuths.

2.2 Angles
Depending on the plane in which they are measured, angles are classified as
Horizontal angles
- Basic measurement for determining bearing and azimuths.

Vertical angles
- For trigonometric leveling
- For stadia measurement.
- For reducing measured slope distances to
horizontal.
Angles are measured by:
Total station
Theodolite
Transit
Compass
By tape: indirect measurement.

Fig 2.1 Theodolite

There are three basic requirements to determine an angle: 1. Reference/starting
lines; 2. Direction of turning; 3. Angular distances (Values of the angle)

Fig. 2.2 The three determinants of an angle

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