Quadrahedral radar reflectors.

[bedouin]

Why as the fourth power?

I think RCS is proportional to the surface area (that's why it is quoted in metres square) so for an octohedral the RCS should be proportional to the square of the linear dimension of the plate.

 

[machurley22]

There is more erudite stuff here.

I once considered hoisting two reflectors, one in the single and one in the double catch rain position in the hope that they would fill some of each others' nulls but I never got a round tuit - another wizard wheeze consigned to the dustbin of history by procrastination.

Dave

 

[capt_courageous]

Hi
It is the square on the receive AND the square on the reflected return hence the four. The radar equation always involves the target as well as the radar.
Machurley - that is a very good site - classic stuff.

 

[bedouin]

You'll need to expand a bit - I think you're wrong about that but I don't understand your logic.

In any one orientation the RCS of the reflector is governed by the product of the radar signal incident on the reflector and the proportion of that radiated back in the direction of the signal.

The first is proportional to the square of the linear dimension and the second is roughly constant for any particular geometric arrangement.

 

[capt_courageous]

No. The RCS is defined by the physical characteristics of the target and the radar wavelength. The signal radiated back is also governed by the RCS. The RCS defines how well it works as a transmitter of returned power as well as how big it looks to the radar. There is a 'gain' both on receive and reflect. Not only does a bigger reflector receive more power it is a better antenna or transmitter for sending the signal back to the radar.

 

[Evadne]

If you have the means, then a reflector directly above another but rotated by 45 degrees is the best way. After all, that is what a Firdell blipper, Echomax etc. are, in essence.

 

[doris]

I take that to mean rotated on a vertical axis. ie. one catching rain and the other on edge?

 

[capt_courageous]

Dave
Look at the site quoted by Machurley22. It shows just how poor the performance of the blipper, mobri etc are compared to a bog standard corner reflector made with circular plates. The mobri came out as invisible.