Sun Path Diagrams
A sun path diagram is a two-dimensional representation of the path of the sun. The program can generate the following sun path diagrams:
Stereographic Projection
This is a circular diagram where the outer edge of the diagram represents the horizon,
and the centre point represents the sun vertically overhead. Solar altitude is
plotted as a series of circles around the centre, these becoming spaced wider apart
as they approach the horizon. This type of diagram increases resolution at low
solar altitudes.
Equidistant Projection
This is a circular diagram where solar altitude lines are equally spaced.
Spherical Projection
This is a circular diagram where solar altitude lines are spaced closer together as
they approach the horizon. This type of diagram increases resolution at high
solar altitudes.
Orthographic Projection
This is a rectangular-shaped diagram where altitude is plotted on the Y-axis,
and azimuth on the X-axis. Both the altitude and azimuth scales are linear.
Waldram Projection
The particular
feature of this diagram is that the vertical and horizontal
scales are such that equal areas on the diagram represent
equal levels of illuminance from the sky.
Animation
A feature of the program is that, for each diagram, for a selected date, the path of the sun can
be animated. Select time interval for the animation and control the animation
with the Start, Single Step, Start/Stop and Reset buttons.
As the animation progresses, current azimuth and altitude are displayed together
with the length of shadow cast by a structure of one unit in height.