How do you determine if a heavy/red radar return is :
- heavy stratus rain (meaning it safe to fly through)
or
- thunderstorm / CB cloud (not wise to fly through)
It's a combination of the latitude you are flying at, and the radar height of the cloud you are studying. The radar is calibrated for temperate zone weather - so gives a falsely strong reading in tropical zones, and a falsely weak reading in desert zones. Calibrated gain adjustments can correct for this
if you know what you are doing! Determining the radar height of the cloud is part of the picture as well.
There are plenty of threads here on it (including Archie Trammel's info):
http://www.pprune.org/tech-log/48016...tml#post440714
http://www.pprune.org/tech-log/37673...her-radar.html
http://www.pprune.org/tech-log/23512...adar-tilt.html
http://www.pprune.org/tech-log/40341...-question.html
etc etc