Re: [Paparazzi-devel] IR sensors

[Martin Mueller]

Hi,

> What is the minimum temperature difference between the sky and the 
> ground that the FMA co-pilot can read?

there is no fixed number for this. It depends on what the sky/clouds 
looks like and how your sensors are mounted in the airframe. The broader 
the view is and the less obfuscated (e.g. by wings), the better. We are 
using a small infrared thermometer (like Graupner #1964) to measure 
infrared radiation. With a difference of 15°C between ground/sky you are 
 on the comfortable, safe side.

> Would the co-pilot work in following conditions:
> 1.) rainy day?
> 2.) snow on the ground and clouds on the sky :-) ?
> 3.) flying through a cloud?
>  
> Did anybody fly FMA co-pilot in foggy conditions, rainy conditions, 
> through clouds?

As long as there is a difference, it is ok. Snow is very rough-textured, 
gives a huge surface and therefore an almost ideal black emitter. Flying 
through a (thick) cloud is not possible.

Martin