In regard to the radar reflector mechanics, here's how the "Ball" reflector works:
It's actually composed of sheets of reflectivve metal, or metal coated paper or plastic.
If you look closely, you'll see that there are three flat surfaces or planes that make up the overall ball shape, arranged at 90 degrees to each other.
Now time out for a short lesson why not to shoot your bear, moose, or urban gang gun into a corner-
If you have two walls at right angles to each other, a bullet fired into that corner will bounce off first one wall and then the other, then come back on a parallel course to the direction fired! Draw it out on paper and see what you get! (Better off not to practice target shooting in a corner in the alley, but if you see a moose there, you're on your own.)
This is a principle that can be proven by a bunch of boring geometry, but one that is used a lot in the real world. (In practice, we have to add a third wall to get a three dimensional corner like up where two walls meet the ceiling to get this to work in our non-flat, three dimensional world.)
Now not too surprisingly, this principle works not only for bullets, but also for light and other electromagnetic waves, such as radar.
This refletive property is used in taillights, parking lights, and reflectors that reflect almost all of the light shown at them right back to the source, making the reflection much, much brighter than it would be if it were just a plain flat surface. Look closely at these tailight and reflector surfaces, and you'll see the little three dimensional corners, and for the reflectors, mirrored surfaces.
This same principle is also used on the reflective tape that was first used on firemen's jackets, and now appears on shoes, rain wear, truck bumpers, etc. The little cubical corners on the tape are just a lot smaller.
Now if we go back to the radar reflector for a minute, we'll see that the ball reflector is made up of many such corners that refelect the radar waves directly back to the source. Such a reflector is much brighter than a simple metal ball, which would only reflect radar waves back on the very small part of the surface perpendicular to the source, with most of the waves bouncing off sideways and to the rear.
Of course, almost anything will return some radar waves to the source, but only a specialized reflector will be virtually 100% reflective. It might not matter whether your boat is highly reflective or not on some inland lake, but with that tanker bearing down on you in the fog out in the Juan de Fuca Straight, you'd want the best reflector you can get on board.
While we're at it, at this point, it's also possible to see just why the stealth airplanes and ships have their angles arranged so that none of them are perpendicular to the source, let alone have any right angled corners in them.
Next time you are bored with the winter doldrums, go out and turn on the radar in your boat and play with some different "targets" to see just how easy or not so easy they are to see on the radar screen.
After that exercise, you can figure out just how demanding the guys are that want radar set ups sensitive enough to be able to see sea gulls flying over baitfish at 6 miles because they know there'll be big fish under the bait!
Joe.
