My limited understanding is...
Anybody have an opinion on what would constitute a stealthy radar friendly shape in space.
I'm thinking that the ideal shape might be a sphere, in that it consistently presents the lowest perpendicular cross-section to a radar type sensor from any direction.
Hi,
I had originally thought that something like a sphere might be a good idea, but based on my limited understanding of Radar Cross Section (from some of the sources others here have posted links to, etc), as I understand it something like a sphere or cylinder may not be that good, precisely because they always present the same cross section to a viewer.
One way of looking at it is if you have ever seen any ray-traced computer graphics of different shapes where you have a light located at the same point you are viewing from. One thing you'll notice is that round objects always have a hot-spot, where they reflect alot of the light shined on them back to the viewer. If however, you have a box, or some other object made up from flat surfaces, and you shine a light at it, from some angles the hot-spot from the light refelcted back will be much stronger than that for a sphere, but from other angles it will be much less.
Although light and radar don't necessarily act exactly the same, as I understand it, in some ways radar (and probably/possibly other sensors) will behave potentially kind of similarly. As such, my limited understanding is that if you can place these flat plates in such a way that they reflect most of the energy directed at them away from the sender, then you could potentially make it much harder to be detected. Of course in doing so you run the risk that there will be certain angles at which you may reflect alot of energy back to an enemies transmitter, but I suppose that ypu try and avoid facing that way as much as possible.
Anyway, here are some 3D images I quickly threw together for a model of an ocean going ship I got off the internet that might help show what I've tried to explain above.
In all the images, I placed the sun right behind the camera.
In the 1st image, you can see that most of the ship is a medium gray color, but that some of the flat surfaces (like the front of the smokestack in the middle of the ship) are darker, which I believe is because alot of the light from the sun is reflected off at an angle away from the camera. However, towards the front of the ship, you can see that the main gun (which is fairly curved and rounded) is lighter in color, which I believe is because its reflecting alot of light back to the camera.
Additionally, just aft of the gun you can see a structure with relatively flat sides that is also fairly brighly colored. I belive that this is the where the ship's Vertical Launch Missile System (VLS) is located, and I belive that it shows up fairly brighly here because the sides of this structure are at an angle to the sun where alot of light is being reflected back to the camera.
In the 2nd image, I have rotated the ship a little and you can now see that the front of the smokestack is now about the same color as the rest of the ship (which I think indicates that at this angle it is now relfecting more light back to the camera). Additionally, the Missile VLS structure is now darker in color (more similar to the rest of the ship) which I think means at this angle it is no longer reflecting as much light back to the camera as before. Finally though, there is still a hot-spot on the gun where alot of light is reflecting back off it.
In the 3rd image, I rotated the ship the other way, to try and illustrate that at other angles, you can end up with some of the flat surfaces reflecting more light back again. Additionally in this image though you can still see that the gun is also reflecting alot of light back.
As such, although as I noted above, radar and other sensors won't necessarily behave exactly like light does, you can still see that for a structure made up of flat surfaces you can possibly reduce the amount of energy that gets reflected off that surface back to the source of the light/sensor signal if you are careful about how you angle the surfaces and how you maneuver your ship with respect to the incoming sensor signals but that a relatively rounded shape (like the gun turret in this example) could potentially reflect enough energy back to the sensor over a wide range of angles due to its shape.
Of course there are probably alot of other things that need to be considered (including the use of coatings and such) but at least this is part of the reason why I suspect that a shape like a sphere may not be necessarily that good for a spaceship if you are trying to reduce the ability of someone detecting you.
I don't know if any of that makes sense, but I thought I'd pass along my thoughts.
Regards
PF
