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View Full Version : Strange Radar Returns (I've got a picture too!!)


fmgc
14th Jul 2006, 10:08
I took this pic of my PFD n the cruise the other day:

http://demo.carrot.co.uk/spike.jpg

Can anybody explain that very strange radar return?

For years I have been flying around wondering what it is. Often seems to occur around central Europe.

PRNAV1
14th Jul 2006, 10:13
as far as i know it's a military radar signal. the weather radar picks these up or so i'm told. flying over iraq you get them frequently, its NOTAM'd to have your weather radar on at all times flying in and around that region so they can ditinguishe you as a civi flt.

Monarch Man
14th Jul 2006, 10:17
Yep its a military radar..Im told its lobe leakage caused by the primary radar bouncing off your own antenna.

Anywhere within 200 miles of Israel/Turkey..ie going to Cyprus or Egypt we get lit up like a christmas tree:sad:
Looks like you were somewhere near the Austrian/Italian/German border.
By the way FMCG..ewwww its a Scarebus!! :)

fmgc
14th Jul 2006, 10:39
MM - it pays the wages! :bored:

BOAC
14th Jul 2006, 11:17
Known to the grey-haired interceptor pilots as a 'spoke' (not sure what the kids call it today:) ). Probably a mil radar on a bearing of 312 from you. It just wipes out that arc as if it were a strong return. Could be someone temporarily 'locked up' to you:eek: or just a strong radar signal.

PS When I were young and clever we used to be able to carry out intercepts of airborne radars like that:{

chevvron
14th Jul 2006, 12:47
Could also be deliberate electronic jamming.

Dani
14th Jul 2006, 13:03
Very correct, this is a spoke. It doesn't necessarily have to be a military radar. It must be one on the same wave length. Obviously it could be a same type.

If a radar sends out an electronical signal, it happens from time to time that it "shines" into your radar for a split second. That's what you see on your radar. In heavy densitiy flying area like Europe or USA, thise spokes are not uncommon.

Dani

Nick 1
14th Jul 2006, 22:00
I use to see the same image , on our older Bus , that appear just for few seconds ,when the WX Radar is turned on .
Bye.

hetfield
14th Jul 2006, 22:25
I have had the same today (like many times bevor) and switched over to 2nd wx-radar.

The "spoke" disappeared.....
:hmm:

A330ismylittlebaby
14th Jul 2006, 22:35
Question: I was watching discovery channel on the naval intercept of an aircraft on the pacific.

And they were worried as the aircraft was transmitting an enemy squawk and not an airliner squawk but why would they rely on sqwark after all, the enemy could easily pretend to have a civilian sqwark.

Eff Oh
15th Jul 2006, 00:45
Just a thought, but if this really is a military radar, and I've seen them loads of times, doesn't that make it easy for an enemy to locate the mil radar head?? Thought mil radars wouldn't really give away their position. Although I have always understood these spokes to be just that. Just a thought, that's all.:confused:

Old Smokey
15th Jul 2006, 04:33
It's so common-place that I looked past the spoke when searching for the anomoly in the picture.

Only one spoke? On a well spoking radar there's so many that they can take up to about 50% of the picture.

Regards,

Old Smokey

Dan Winterland
15th Jul 2006, 05:53
It's a spoke. In this case, it's highly likely to be a Soviet era SA2 'Guideline' Surface to Air Missile search radar. It's frequency is very similar to that of airborne weather radar which is why it shows up so often over Eastern Europe and the Middle East.

And does it make them easy for the enemy to spot? Sure does! In a battle, lighting up someone like that is a sure fire way to get an anti-radiation missile like HARM or ALARM to heading your way. These home onto the transmissions. This would make you switch off the radar, or lose it. But switching off the radar may not help either. The British ALARM missile climbs to height and pops out a parachute if it loses the signal. When the radar fires up again, off it goes again!

And of course, being able to receive radar transmissions is a useful defencive aid. If you're in a transport aircraft for example, recieving transmissions from enemy radars is a good cue to be somewhere else!

TruBlu351
15th Jul 2006, 08:35
Just a thought, but if this really is a military radar, and I've seen them loads of times, doesn't that make it easy for an enemy to locate the mil radar head?? Thought mil radars wouldn't really give away their position. Although I have always understood these spokes to be just that. Just a thought, that's all.:confused:

....and because the bad guys know they light themselves up like a christmas tree, then sometimes lauch missiles ballistically. ie: Flying phone pole at mach 3....smoke trail is quite scary to see outside, but there's no radar guidance.

With nothing elso to do, I'd be playing with the tilt to try and get the biggest cherry red return :ok: Then you can play with your 1 in 60's to get your eyeballs outside :8

allyn
15th Jul 2006, 18:14
Slight drift in topic but it's kind of related:

http://en.wikipedia.org/wiki/Wild_Weasel

captain_jeeves
17th Jul 2006, 11:17
I took this pic of my PFD n the cruise the other day:



Can anybody explain that very strange radar return?

For years I have been flying around wondering what it is. Often seems to occur around central Europe.


A WX Radar antenna will, often, act like a gyro and experience a level of momentary precession when acted upon by Acceleration, Deceleration, Turning or very light chop. Typically, it will happen when the change in motion is quite small.

If this WX Radar image was only momentary, it was probably the result of that precession phenomenon, and is in fact, a ground return.


Reference: Manufacturers WX Radar users manual

.

BOAC
17th Jul 2006, 11:57
I suspect this antenna is phased array, Cpt J? Cannot see AB having anything so ancient as a moving dish:oh:

captain_jeeves
17th Jul 2006, 12:06
I suspect this antenna is phased array, Cpt J? Cannot see AB having anything so ancient as a moving dish:oh:

I am not an expert on this, so this is why I quoted the manufactures manual. PM me and I'll send you a pdf copy of it so you can read it for yourself.

BOAC
17th Jul 2006, 12:55
Thanks, but no, CJ - want to stay 'pure':oh: