Hello,

I am new to that group and already have a big
question:

I need the parameter fixed water vapor in precipitable
mm for an atmospheric correction of a satellite image.

Therefore, I collected data of a radiosonde
(geopotential height, temperatur, relative humidity,
pressure)at acquisition time. I thought that these
data will help.
Unfortunately, I can't remember what formula to use.
My first guess is calculating the saturation pressure
es at each temperature (magnus formula) in order to
get the water vapor pressure e from the relative
humidity. rh = 100*e/es.
Then use the ideal gas law: absolute humidity= (e*M
(water))/ (R*T).

Hence, I'll end up with an array of absolute humidity,
but my question is further, assuming the calculation
above is right, whether I have to integrate those
value over the height in order to get precipital mm.

Any hint or correction would be helpful!

Thanks a lot,

Lucia

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