Originally Posted by Graybeard
Maybe you use both terms indiscriminately, CJ, but that doesn't make it right, especially when the topic is related to EMI. As you know, the radio altimeter is FMCW, and radar altimeter transmissions are pulsed. Those are quite different in terms of potential for EMI. Military techies and others just may get confused. In fact, there were radar altimeters used on 737s many years back.
It's more a matter of definition and terminology than anything else....
Your definition is as good as anything, and "radio" altimeter seems to be more widely used than "radar" altimeter (flipped through a few manuals, and checked Trubshaw's book, who also calls them "radio" altimeters, although on the first flight of 002 he probably called them something else... The French also use "radio-altimètre".)
Just the same, FMCW
is a form of
radar, and the Bible ("Radar System Engineering" by Ridenour, Rad Lab) calls the grand-daddy of them all, the AN-APN1, a
radar altimeter.
Reminds me of the endless confusion with the term FBW.....
As to EMI, I totally agree, FMCW and pulse altimeters would present quite different issues.
Cheers,
CJ