Military History | How To Make War | Wars Around the World Rules of Use How to Behave on an Internet Forum
Fighters, Bombers and Recon Discussion Board
Sign In   Return to Topic Page
Subject: I find this interesting
FJV    5/27/2009 3:39:25 PM
Source: "http://www.forecastinternational.com/notable/isr1.pdf" link
 
Quote    Reply

Email Me When A New Comment Is Made
Show Only Poster Name and Title     Newest to Oldest

Pages: PREV  1 2 3
Galderio       5/28/2009 11:27:48 PM
I believe the original ATF was suposed to have conformal AESA radars on the wings shoulders, but they give up this idea because the price would be to high.
Price was more important than size. I guess.
 
Quote    Reply

WarNerd       5/29/2009 6:32:55 AM

I believe the original ATF was suposed to have conformal AESA radars on the wings shoulders, but they give up this idea because the price would be to high.
Price was more important than size. I guess.

The price was probably for developing and testing the design, which would have been a first of it's kind.  The odds of unforeseen problems developing and producing delays would have been very high and would have negatively effected the entire project schedule.  Given the problems that they were already facing they probably decided that this was one potential headache they could do without.
 
Quote    Reply

warpig       5/29/2009 2:19:28 PM


When you have two separate systems putting out phase interference you have to work out beam geometry and clean up the sidelobes for starters. This is a classic bolo with own radars and own active jammer systems or same telemetry links, same platform, as you are all too aware, WP.


Often it comes down to simple point geometries and scan schemes. The antenna has to be moved or the radio beams pointed away from each other so that radio beams as they scan through the same volume of space don't cross each other.  Or you can develop an electronic phase canceler thbat acts as a noise gate.







Its sounds so easy. It isn't, which is why the American aircraft AESA radars are so phenomenal and why the SPY 3 is taking so damn long to perfect.


Ahhh, thank you.  Now that you point this out, I do recall reading about some fighters that carry self-protection jammers, but using them blanks out their own AI radar because of destructive interference entering through sidelobes.  Obviously a problem in general, but particularly so while in the process of trying to track a target or especially while in the process of firing and guiding a missile towards a target!  I guess it's safe to say that working this problem out so you can jam the threat without jamming your own radar (and your wingman's!) is definitely quite an important consideration during design of both the radar and the jammer.  Seems like a strong rationale for why you would want the two design teams to be fully interactive right from the beginning, instead of hoping to kluge on an add-in jammer system later on.  Sure you may be able to hang a nifty pod from KNIRTI or ELTA, but I guess that doesn't mean everything is automatically going to work together without a hitch.

 
Quote    Reply

gf0012-aust       5/29/2009 9:17:23 PM
I do recall reading about some fighters that carry self-protection jammers, but using them blanks out their own AI radar because of destructive interference entering through sidelobes.  Obviously a problem in general, but particularly so while in the process of trying to track a target or especially while in the process of firing and guiding a missile towards a target!  I guess it's safe to say that working this problem out so you can jam the threat without jamming your own radar (and your wingman's!) is definitely quite an important consideration during design of both the radar and the jammer. 

the $64,0000 rhetorical question is:
does air based CEC where one hunts and another jams (at a distance) still suffer from tyhe same degree of problem.  ie is the interference substantially localised or does it diminish exponentially when the tasks are discretely handled by different aircraft.

ie a variation of the hand-off theme. 
 
Quote    Reply

Herald12345    Un verse square law and Heddy Lamarr.   5/29/2009 10:13:33 PM


I do recall reading about some fighters that carry self-protection jammers, but using them blanks out their own AI radar because of destructive interference entering through sidelobes.  Obviously a problem in general, but particularly so while in the process of trying to track a target or especially while in the process of firing and guiding a missile towards a target!  I guess it's safe to say that working this problem out so you can jam the threat without jamming your own radar (and your wingman's!) is definitely quite an important consideration during design of both the radar and the jammer. 





the $64,0000 rhetorical question is:

does air based CEC where one hunts and another jams (at a distance) still suffer from tyhe same degree of problem.  ie is the interference substantially localised or does it diminish exponentially when the tasks are discretely handled by different aircraft.




ie a variation of the hand-off theme. 

Herald
 
Quote    Reply

Herald12345    Un verse square law and Heddy Lamarr.   5/29/2009 10:15:09 PM
Gagh, TYPOS! Inverse square law and Heddy Lamarr.
 
 
 
Quote    Reply

gf0012-aust    Herald   5/29/2009 10:50:46 PM

Gagh, TYPOS! Inverse square law and Heddy Lamarr.

 
curious as to your views on the Lambert Guidance System...  pro's and con's.
 

 


 
Quote    Reply

Herald12345       5/30/2009 12:48:17 AM




Gagh, TYPOS! Inverse square law and Heddy Lamarr.



 

curious as to your views on the Lambert Guidance System...  pro's and con's.

 



 






It will work against a Nodong, but not against a Topol for one thing. Any variable that changes the final velocity constraint (limit) of the chaser makes the problem of matching the velocity increment over tau an external telemetry update problem for you until you exhaust fuel at which moment you are left with the potential energy that you have to manage carefully to meet your predict point where you greet whatever you planned to rendezvous with.  As long as it is a two body or three body predictable velocity problem you can use it to make a rendezvous close, but you need some reserve energy advantage (fuel and burn time) and some way to finally guide in to make close rendezvous.
 
Its chief advantage is that it is an onboard guidance, doesn't require continuous point update (you aim at a window and match your terminal solved velocity to reach that window) and correct for velocity difference with clocked updated burns so its virtually spoofproof and jammer impregnable as a guidance. Its also SIMPLE since it can work purely with inertia guidance.alone without external referent as long as you have a CLOCK. 
 
Herald
 
 
 
Quote    Reply

warpig    Bump   4/1/2010 3:28:16 PM
This one started getting into some real content that is not often discussed, and thus I figured it is bump-worthy.
 
Quote    Reply

Hamilcar    How missiles' guidance works.    4/8/2010 9:27:55 AM
Too many people lose track of system choice limit explanations because they cannot segment trajectories and visualize why physics limits some time ordered solutions to guided weapon problems. They cannot see that even something as simple as an IR chase missile's path has to be sliced into parts, clock matched, and that why each slice results in a signal drift correction, and why those trajectory corrections as applied, are measured as fractions of arc/seconds to either follow lead, or predict lead the strongest signal in the sensor field of view.      
 

That confused you? It should, but it is accurate.
 
 
 
 
 
 
 
Have fun with it.
 
H.
 
 
 
 
 
 
 
 
H.
 
Quote    Reply
PREV  1 2 3



StrategyWorld.com© 1998 - 2012StrategyWorld.com. All rights Reserved. StrategyWorld.com, StrategyPage.com, FYEO, For Your Eyes Only and Al Nofi's CIC are all trademarks of StrategyWorld.com Privacy Policy