On Jul 23, 7:37*am, Mxsmanic wrote:
It's easy enough to establish measurement stations on the surface to measure
wind, temperature, visibility, etc., but what is the normal way for
meteorologists to measure these things aloft? *Do they depend on PIREPs, or
expendable/recoverable probes and balloons, or satellites, or what?

Theres a little "eye" that looks up at the sky at various points. It
detects if there is cloud, or sky. The sensor is prone to errors,
though. Sometimes if it's broken, it'll say its overcast because some
of the sensors are pointing diagonally and are sensing the side of the
cloud. I had an ATC college-style text book that had a very
informative diagram of how they worked, but that book is long gone.

http://www.cyanogen.com/products/cloud_main.htm

here is an example of one.