Environmental Engineering Reference
In-Depth Information
Figure 2.18
Definition of the Obstacle Height Angle and Obstacle Azimuth
Using a Freely Chosen Point of Reference
The height angle
γ
is:
h
2
-
h
1
d
∆
h
d
γ
= arctan
= arctan
(2.36)
These calculations must be performed for all possible obstacles in the vicinity
of the planned solar energy system. Specialized instruments can be used to
estimate object height and azimuth angles more easily. In addition to expensive
surveyor's transits, simple instruments can be also used. A solar position
diagram with a trigonometrically subdivided height axis and a regular 180°
azimuth axis is the basis for such an instrument. This diagram must be copied
onto a transparency, which is then bent in a semicircle. The observer looks
through this diagram to the objects and can directly read height and azimuth
angles as shown in Figure 2.19.
It is also possible to take digital photographs of the surroundings and to
use professional software to analyse it. This software automatically estimates
azimuth and height angles.
Figure 2.19
Estimation of Object Azimuth and Height Angles Using a Simple
Optical Instrument
