Undetectable Radar

classic Classic list List threaded Threaded
3 messages Options
Reply | Threaded
Open this post in threaded view
|

Undetectable Radar

Mark, KJ7BS
Keep an eye on this one.  Undetectable Radar!  The inventor says it sounds like static on a receiver.

http://tinyurl.com/nf7aq

BTW:  It is an interesting end to the URL the TinyURL generated for this link.

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

Reply | Threaded
Open this post in threaded view
|

Re: [QRP-L] Undetectable Radar

Leon Heller
----- Original Message -----
From: "Mark Saunders, KJ7BS" <[hidden email]>
To: "Elecraft Mail List" <[hidden email]>; "QRP-L Mail List"
<[hidden email]>
Sent: Tuesday, June 27, 2006 4:16 PM
Subject: [QRP-L] Undetectable Radar


> Keep an eye on this one.  Undetectable Radar!  The inventor says it sounds
> like static on a receiver.
>
> http://tinyurl.com/nf7aq



It doesn't look much different from a standard spread-spectrum signal. They
aren't exactly undetectable, the IRA could tell when the British army were
in the vicinity and using SS signals because they could hear the increased
noise level on the scanners they used to monitor the military radio
channels.

Leon

______________________________________________________________
QRP-L mailing list
Home: http://mailman.qth.net/mailman/listinfo/qrp-l
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

Reply | Threaded
Open this post in threaded view
|

Re: Undetectable Radar

Stuart Rohre
In reply to this post by Mark, KJ7BS
Mike, in radar as in QRP, there is no free lunch.

Rest assured any broad spectrum signal can be found.  For one thing it
inevitably brings up the noise floor and that can be detected.  Good
receivers like the K2, could be helpful in noting such effects from new
radars or BPL use in an area.

Spreading your signal out over many frequencies with a noise like character,
your radar then suffers from lack of coherency, and thus your range will be
affected, and perhaps its discrimination of the size of objects.

However, there are systems being studied that look at the effect on the
spectrum of objects moving thru.

(like the flutter on your TV signal when a plane flies over)

That passive sort of radar has much to offer.  There is no emanation from
the site of the radar receiver, and thus the target generates the only
signal.  A couple of receivers provide the ranging by comparing delays in
signals effects.  Again range suffers, and you have to have a super quiet
receiver to extend range.  No free lunch, but the trade offs are attractive
from the stealth angle.

Stuart
K5KVH


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com