Hi! I´m working with Landsat7 and Flaash too. I´m having a lot of problems to understand each parameter, but this guide has helped me a lot. http://www.ittvis.com/por...vi/Flaash_Module.pdf Hope it helps!

Hi, well I am no expert, but I have been dealing with Landsat and ASTER in semi-arid regions. Basically you set up everything according to the FLAASH guide. The only thing you will have to play with is the the atmospheric model, the visibility and if you have data from an arid environment you will most probably have to adjust the water column multiplier to some value lower than 1, unless you want to use a winter atmospheric model, which doesn't make much sense in tropics. You can experiment and see what is the amount of water vapor calculated after a run of the FLAASH module and than adjust the multiplier in an iterative way so that you arrive to a value appropriate for your conditions. This is the way that I did it, although I have never ever found much about the function of the water column multiplier in any manual.:) so maybe I am completely wrong... Cheers Vaclav