Simple radar detection model

[sobek]

Another viable method is using really high PRF to get a lot of accurate returns with both range, speed, heading, azmiuth, and elevation data, but again, because the PRT is so small, range is limited. However short range SAMs don't go far enough to really care.

 

With newer solid state radars, can't you just use PWM in a pseudo-unique way so every pulse stays identifyable regardless if a new one has been sent?

[Sgt_Baker]

With newer solid state radars, can't you just use PWM in a pseudo-unique way so every pulse stays identifyable regardless if a new one has been sent?

 

Hi Folks,

 

I apologise in advance for diverging quite significantly from any notion of "simple" in the latter part of this post.

 

I believe this technique mentioned by sobek has been in use for quite a while. I'm specifically thinking of instances where amateur HAM operators would deliberately "jam" (annoy) the Woodpecker radars by playing back pseudo-random pulses from earlier, recorded, transmissions.

 

Regarding RCS modelling, would it not be a relatively simple matter to shove monochrome versions of DCS's aircraft models through a readily-available raytracer (with ambient occlusion etc)? I was thinking that you could generate images from a select number of azimuth and elevation angles, then simply average the resultant images from each angle with a view to generating an "average brightness" of the target, thus being able to generate a rather simple 3D model of the RCS. Think of it as having 100 RCS averages, then creating a 3D Bezier/NURBS/Whatever surface from those (now) vectors. If one were feeling particularly anal one could alter the initial model's material properties based on their assumed radar reflectivity.

 

There we go. I'm waaaaay "off piste". And I know that radar and light are many, many nanometres distant. :)

 

Best regards,

 

Baker

[sobek]

Regarding RCS modelling, would it not be a relatively simple matter to shove monochrome versions of DCS's aircraft models through a readily-available raytracer (with ambient occlusion etc)? I was thinking that you could generate images from a select number of azimuth and elevation angles, then simply average the resultant images from each angle with a view to generating an "average brightness" of the target, thus being able to generate a rather simple 3D model of the RCS. Think of it as having 100 RCS averages, then creating a 3D Bezier/NURBS/Whatever surface from those (now) vectors. If one were feeling particularly anal one could alter the initial model's material properties based on their assumed radar reflectivity.

 

I'm not sure i understand the procedure fully you propose, but wouldn't that completely disregard the wavelength<->target size relationship and the associated peculiarities of radar?

[Sgt_Baker]

I'm not sure i understand the procedure fully you propose, but wouldn't that completely disregard the wavelength<->target size relationship and the associated peculiarities of radar?

 

Yes, in that brief summary those factors are ignored for the sake of brevity, but not entirely beyond the yield of the concept in my opinion. Hence my closing "many nanometres apart". There are numerous approximations made during the initial proposal, yet the factor of wavelength could be modelled, versus each radar frequency, by the degree of "blur" (averaging) applied to each az/el sample (as opposed to full-frame for the long-range/long-wavelength search radar I was referring to initially). All of those calculations are an offline process, so cost the actual game very little when compared to "versus radar XYZ use RCS ABC".

 

Fundamentally, if one were looking for a vague approximation of RCS, as opposed to complete assumption, one couldn't start in a cheaper place than the idea I mentioned and develop the concept from there if required/desired.

 

How else do you think they design low-RCS jets before plonking for a scale model?

 

It's worth mentioning that Microsoft Allegiance implemented a mathematically non-uniform model of radar back in 2000. If that worked "way back then", I'm relatively certain a "slightly realistic" modelled RCS based on the above would prove very efficient in the age we live.

 

As I said, it was all off-piste, but worth mentioning given this being the most interesting thread I've read so far.

 

Baker

[Eihort]

As long as the raytracer was adjusted for RF, as it behaves completely differently than visible light, even the occlusion, that could work.

 

Be really funny to use the 3D model of the RCS instead of the physical models and see these strange mis-shapen blobs flying around. LOL