Solar Position and the Sun-Path

Sun-Path Diagrams are a way of modelling and visualising the path of the Sun through the sky at a specific geographic location. With a little interactivity and a small element of play, such diagrams can significantly contribute to our understanding of how the Sun is likely to interact with a building - a concept crucial to the effective design of shading systems. This applet presents just such a Sun-Path diagram, allowing you to interactively change date, time and location as well as viewing it in a range of different ways.

Blog Details

Example Sun-Path Applet: The relationship between spherical and orthographic sun-path projection methods. This is an interactive applet so you can adjust the sun position by clicking and dragging it with the left mouse button or use the middle and right buttons to pan or rotate the view.

Description

A core understanding of sun position and the solar cycle is fundamental to many aspects of good design. Used correctly, the Sun can be the main source of both passive heating and cooling in a building. The aim of this applet is mainly educational - a tool with which you can experiment and play to improve your own design understanding.

See the Earth-Sun Relationship and Sun Path Diagram Projection Methods topics for more detailed information on other aspects of solar position and projections.

Display Options

You can use the OPTIONS button menu (F4) to change the main display settings, as shown in Figure 1. This menu lets you toggle overlay panels that show solar information, the world map and simple instructions. You can also use it to change the size of the world map, overlay world time zones or select different views of the model.

Using the Display Options… menu item (F5), as shown in Figure 2, you can determine what components of the sun-path diagram are displayed and how they are shown. This allows you to tailor the image to suit your particular demonstration or application.

The only real way to understand the use of these applets is to experiment, so please feel free to simply play about with it.

 

 

Comments

2 July, 2013 - 21:14Craig Hollabaugh

Andrew,

Did you publish the source for this mighty fine tool? Or do you have a standalone jar available?

Thanks, Craig

5 June, 2013 - 15:40Dave

Thnx to this application so much!! I finally get a clear visual for my building presentation. I wish i can download this software so i can use it when im offline too. Pleassseee anyone can made this happen so i can turn it on whenever i need it. Thnx.

23 July, 2012 - 11:56Professor Gerhard Prinsloo

Dear Andrew

The messages I sent to you previously keeps coming back with the msg : not delivered (hope this goes through).

We find your Sun Path Graphics on this page most helpful to explain the Sun Path Diagram to students:

http://andrewmarsh.com/scripts/educational/solar-position-and-sun-path

I am lecturing at a university in Africa and we use a small Arduino processor based solar tracking model to demonstrate to the students how a Parabolic dish follows the sun. Students find this very instructive.

I was thinking, if I can somehow get an output from your algorithm on the Azimuth and Elevation position of the sun (while moving the sliders) that we can send to the Arduino processor, it will have a very helpful model to demonstrate the motion and understand the Sun Path Diagram even better.

For example if the parameters can be written as a string to the USB port then we can read this into Arduino and demonstrate the parabolic dish movement with the Sun Path Diagram.

Do let me know if you are willing to assist us in accomplishing this to help our students.

best regards Professor Gerhard Prinsloo prinsloo@dut.ac.za

Durban University of Technology

23 July, 2012 - 19:15Dr. Andrew Marsh

Hi Professor Prinsloo,

I would be more than happy to help in any way I can with your project. I will contact you directly by email to follow up…

Andrew

26 September, 2010 - 19:04renato

Congratulations Andrew.

Outstanding job. I rarely see such an incredible development. Absulutely everything necessary to this subject. Pervect.

3 September, 2011 - 19:50KimBob

Andrew, Excellent piece of software. This is so intuitive and easy to use. Thanks for sharing!

For those who wanted to know how to find the position of their city, go to http://itouchmap.com/latlong.html and enter your address. The map will show you latitude and longitude which you can then position Andrew’s map to those coordinates.

15 April, 2011 - 19:17David Carlson

How do I get the sun angles for my home at 15950 Portico Drive Wayzata MN 55391?

26 March, 2011 - 06:23J N Karamchetti

It is really amazing. I used it for 3 hours with different latitudes and longitudes - and interactive and give excellent pictorial view or understanding for the viewer.

Thanks to you keep such thing in public domain.

28 February, 2011 - 10:18Diane

Amazing… I’ve actually understood what azimuth is now… So well represented.

31 October, 2010 - 18:10John

Hi-

HOW DO I USE THIS APPLET TO GET A DIAGRAM FOR LOCATION IN NYC?

This is amazing. I am trying to use the applet to create a sun diagram for location in Brooklyn, NY:

92 Plymouth Street, Brooklyn, NY Zip 11201.

Is there a way for me to do this? Can you tell me how?

24 January, 2012 - 01:10Alex K

John-

There are many programs available online that will allow you to select a point on a map and will tell you the latitude/longitude of that point. Once you find the lat/long of the address, use the lat/long sliders on the sides of Andrew’s application to get as close as possible to the point.

Here is an example: http://itouchmap.com/latlong.html

11 October, 2010 - 16:28Gianluca Brilli

Very beautiful and interesting.

Click here to comment on this page.

< PREV BLOG: Interactive 3D in a Web Page NEXT: The Earth-Sun Relationship BLOG >
© Dr. Andrew J. Marsh, 2023 - Some rights reserved.