In article ,
"Peter Duniho" wrote:


Visible satellite should not vary in brightness according to altitude. But
infrared does. Perhaps the XM images are from the infrared satellite, as
Casey suggests.

hmmm. Looking at sat pictures from http://adds.aviationweather.gov/satellite/,
the visible sat picture sure seems like the brightness varies with altitude,
if only because the higher clouds can catch more sunlight.

But the B&W infrared images don't seem as good at showing low clouds
as the visible sat images.

The color infrared and the water vapor images are definitely better
at showing lower clouds.

--
Bob Noel
Looking for a sig the
lawyers will hate