[btw0]

I use it to watch the air condition of Beijing urban area http://madk.org/beijing-sky-photo.html

[bennyg]

This is a cool project idea. You should run some sort of automated "clarity" detection to get numbers/statistics on air quality in Beijing.

[btw0]

Thanks. I am thinking about the same thing on the "clarity" detection and numbers can be used to do some visualisation. Yes, I am going to try it out.