I am searching for images of the daytime sky taken within the water vapor absorption bands at 940nm, 1600 nm, 1860 nm, 2700 nm or 2900 nm. Specifically I am trying to see if multispectral images of in-band and adjacent out-of-band photos could be subtracted to show areas of slight water vapor differeneces (~1%) in a clear sky at distances of 500 meters to 1500 meters. I have hopes that someone must have done this and published the results, but I can't seem to find it. I would do this myself but the price of bandpass filters above 1000 nm. is very expensive.