Science Cloud Altitude Meter

[Notebook]

A project from Elektor magazine.

Haven't got the magazine yet, so only have this promo:
http://www.elektor.com/uploads/pageflip/pageflip_uk/index.html

Website project here:
http://www.elektor.com/magazines/2010/may/cloud-altitude-meter.1321986.lynkx

I've downloaded the software(have to register), but dosen't make much sense to me . Its "C" for a ATmega324PA-AU.
Was looking for the August-Roche-Magnus formula, but maybe its hidden in the hex files?

Edit: not so hidden, the functions are in tlkRH.c

http://en.wikipedia.org/wiki/Atmospheric_thermodynamics
At first search its not easy to find anything on this formula.

Interesting project, might make more sense when I get the magazine.

N.

 

[RisingFury]

Don't look for explanations of complex effects on Wikipedia. It just gives a hand-wavium explanation, with no mathematical description.

 

[Hielor]

Sounds like it's using the temperature/dewpoint spread and the standard atmospheric lapse rate to determine the approximate altitude of the cloud base.

The standard temperature decrease is 2 degrees celsius per thousand feet of altitude. If you're at ground level and the temperature is 10, the dewpoint is 6, then you can guesstimate the cloud bases to be at around 2000 feet, since at that altitude the temperature will have dropped to the dewpoint, resulting in condensation.

Sorry if that's a poor explanation, it's 4 in the morning here

 

[Notebook]

To RisingFury:

I was hopng for a few pointrs from wikipedia, but...
Elektor always has good links from its articles, so more info when I get the mag.

To Hielor:
Thats what I thought, the (adiabatic)? lapse rate is about the only thing I can remember from my met. when I was flying

N.