Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!uunet!aplcomm!tedwards
From: tedwards@aplcomm.JHUAPL.EDU (Edwards Thomas G S1A x8297)
Newsgroups: sci.electronics
Subject: Re: R.A.M. (was Re: Police Radar Frequency Info)
Summary: Stealth Detection
Message-ID: <458@aplcomm.JHUAPL.EDU>
Date: 21 Jun 91 20:37:45 GMT
References: <1991Jun14.211314.16835@en.ecn.purdue.edu> <2003@ole.UUCP> <1991Jun18.005130.28440@cs.mcgill.ca> <2017@ole.UUCP> <7372@celery15.UUCP>
Reply-To: tedwards@aplcomm.jhuapl.edu (Edwards Thomas G S1A x8297 )
Organization: JHU/APL, Laurel, MD
Lines: 39

In article <7372@celery15.UUCP> skeffing@motcid.UUCP (John F. Skeffington) writes:
>In article <2017@ole.UUCP> ssave@ole.UUCP (Shailendra Save) writes:
>>  If RAM worked 100%, like you contend they do, how come
>>  Czechoslovakia has come out with a detection method which can detect
>>  the Stealth aircraft at 250 miles?

>Where have you heard about this new detection method?  I do not recall
>any knowledgable person on stealth technology claiming the aircraft was
>invisiable to radar, rather it was difficult to detect.  The implication
>of being able to detect a stealth aircraft at 250 miles woufd be that
>it could detect a "normal" aircraft at several times that distance.  I 
>find this very interesting and would like to know more about it. 

Not actually.  RAM does a fine job of attenuating reflection of radio   
transmissions over a range of frequencies.  For a single frequency radar
operating within the reflection attenuation band of the RAM, it will be
very difficult to detect it.

However, it is possible to implement a "chirped" radar system or a
multiple xmitter radar site which is capable of integrating reflection
information over a large range of frequencies to bring a stealth aricraft
signal out of the noise.   

The moral of the story is that while the U.S.S.R. might be capable of
producing anti-stealth radar (assuming they can get enough info on the
stealth aircrafts to do proper testing of the system), a small country with
less technical knowledge and money would find this much more difficult.
The radar sets required to detect it will be more complex and expensive than
normal radar systems (and being more complex may make it more prone to failure).

Also radar xmitters trying to detect stealth aircraft will be easily
identifiable, and it may be difficult to implement a stealth-proof radar
system which can fit into a fighter.

Any defense one can build will be an easy target for someone else's 
offense...

     
-Tom