Comments on: Math behind a world sunlight map

By: Admin

Admin — Sun, 27 Feb 2011 14:22:52 +0000

Hi Dan,

These images are made by NASA. I just mailed them to you. If you want the even bigger versions (originals) you should check at the nasa website. They’re free.

Regards,

Jurgen

By: Dan

Dan — Fri, 11 Feb 2011 20:40:48 +0000

Would it be possible to download your bigger images, too (i.e. day.png and night.png) instead of just the _live versions? Thanks!!!

By: AVEbrahimi

AVEbrahimi — Wed, 22 Dec 2010 01:37:57 +0000

Thank you for vivid and professional documentation.

By: Admin

Admin — Tue, 07 Dec 2010 14:20:21 +0000

Thanks Carlo!

Actually, the image you see here is a mercator projection. The sphere I’m talking about is just a modelling trick to calculate illumination for the map. The part about ‘mapping’ is where I discuss the transformation from the sphere model to the 2D mercator map, the result. Contact me if you need more help.

By: carlo

carlo — Sat, 04 Dec 2010 16:49:44 +0000

Hi very nice work! Really!
I’m planning to use your script to generate a sunlight map for a project. Unfortunately I’m using a flat mercator projection (not projected on a sphere) and I can’t understand how to change the math to create a proper sunlight map. Could you give me some suggestions? Thanks!

By: Admin

Admin — Sat, 23 Jan 2010 10:47:37 +0000

These “headers already set” error is usually caused by some echo/print output or any content outside of your tags. You should locate the line causing the output of your script. Btw, I use Apache 2 httpd.

By: WorldSunRise

WorldSunRise — Mon, 09 Nov 2009 20:42:11 +0000

Tried your script, but it doesn’t generate map picture. Not sure, but it might be because of “header already set” problem. t.i. do you have any tip? What web server you use?

By: Uira Cocha

Uira Cocha — Fri, 05 Jun 2009 20:18:16 +0000

Beautiful!

Thanks for your article and for making public the source code of its implementation in PHP