Radar head sites England and Wales
 

Does anyone know of a publically available "definitive" list of Mode-S and Mode A/C radar sites across England and Wales please.
Details to include location ,II /SI ident where applicable and rotation speed ?

For some reason there seems to be a lack of public information for England and Wales....and yet for Scotland , all of this data has been revealed in various wind farm location studies.

The info is required for experimental research into a method for positioning a/c in response to their interrogation by radar heads.

I could make a FOIA request , but that seems rather OTT.

Many thanks

For security reasons it may not be a particularly good idea to publicise such matters?

http://i79.photobucket.com/albums/j1...f?t=1306396749

I'm not sure I buy the security aspect....radar heads are easilly spotted and not exactly hidden . The rotation speed can be measured by simply looking at the revolving head.

All the data seems to be available where wind farm assesment is concerned , so why the secrecy?
I suspect its more to do with the competition between major contractors.

The theory certainly seems to work for both Mode-S as above and Mode A/c , but it would be nice to be able to fill in the gaps.

Nice gif! What's it from?

The gif is from COAA's PlanePlotter
PlanePlotter has developed its own unique multilateration system to locate and track Mode-S a/c and is now working on the radar interrogation/location system .

This is the Mode A/C system in action
http://i55.tinypic.com/2ut52qp.jpg

Why not write to NATS and ask them?

Or better still try Directorate of Airspace Policy (DAP), Civil Aviation Authority. There are other operators as well as NATS, and CAA will have records of them all along with the technical data you require.

Many thanks both I did try NATS , but no response, however the Directorate sounds a great idea !

You should also consider Ofcom since they license them.

(A search of Ofcom for Debden came up with a map of band L radars in 2 mins. Also found a table listing numbers of radars by type in another 3 mins.)

A search of the CAA web site with Debden came up with the coordinates of all primary and secondary radars for Stansted, Heathrow & Gatwick so it's not a big secret.

... and a quick look at Eurocontrol's web site found a paper with a map of all Scottish radar heads used for ATC.

Well all the information is freely and easily available on the NATS intranet if you're a member of NATS so I'm surprised you never got a response. Who did you write to? Did you try the Head of Surveillance Sensors at the Corporate HQ in Whiteley?

BD

In the 1980s I seem to remember the Irish Republican Army blew up the Mount Gabriel radar facility in Southern Ireland as they perceived it to be part of the "British War Machine"

google radnet; might bring forth some info

I googled Radnet cant find anything on radars just radiation!


ANN 534610N 0025930W 120
BUR 505600N 0035915W 180
CLE 522350N 0023600W 180
CLX 532700N 0001830W 250
DEB 515925N 0001550E 160
GDF 544100N 0022700W 250
JSY 491230N 0021145W 120
PEA 510500N 0001245W 160
H23 512825N 0002715W 80
H10 512820N 0002635W 80
G10 510840N 0001125W 60
S10 515255N 0001330E 60
M10 532100N 0021725W 60

:ok:

Just out of interest, why do some of the NATS HSA 23cm radars have 'golf-balls' while others are open to the elements? Is it just cost vv the 'windyness' of the site?

Radomes
 

As far as I understand it the radome (golf ball) protects the radar from the wind meaning that less power is required to turn the radar. The radome slightly weakens the radar signal as it passes through it.

In short windy sites, such as Lowther Hill in Scotland tend to have radomes whereas less windy sites do not.

Many thanks for all the replies and suggestions

As can be seen from the graphic below the site locations , rotation speed and pulse rates can be reverse engineered , but it would be preferable to tighten up the spec using the official info.
I have been advised that the request to the CAA has been accepted and should hear from them within 28 days.

The animation demonstrates the Mode A/C heads in action , white beams , plus two main Mode-S [red beams] which are Heathrow and Bournemouth which I have used as fill ins.
The site south of Teeside is actually misplaced by a few miles and is yet to be formally identified.



http://i79.photobucket.com/albums/j1...images/Ezy.gif

It also means the radar can still turn in high winds in stead of being stopped.

Like the Type 80 at RAF Saxa Vord?
Redirect Notice

It did get rather windy a lot during the winter, but hardly any snow which is another reason for radomes, like the one at Great Dun Fell. Very convenient hill for the Saxa radar which enabled us to 'look down' and see the choppers coming off the rigs when the RAF did that work through Shetland Radar.

BD

Planeplotter [PP ] has the ability to assess the rotation speeds of the radar heads in addition to seeking out their approximate location.

What is interesting is that the rpm we are seeing , estimated to three decimal places , varies quite considerably from site to site.
Most are rated 15 by NATS , however none are exactly that figure , tending to be between 15.2 and 15.8

I wondered if perhaps the rotation is checked and calibrated on a regular basis.
Is the true rate exacly 15 and are the variations artifacts of the PP software or do they really rotate at varying rpm ?

The longer the range for the radar to 'see', the slower the rotation rate. Most en-route radars rotate at around 7.5 RPM (individual sites range from 7 to 7.6). Shared en-route and airfield facilities will be in the order of 10 RPM (sites range from 9.72 to 12). Radars primarily used for airfield ATC will be in the order of 15 RPM (sites range from 15 to 15.7).

The exact rotation rate is known and controlled by the ATC control and monitoring systems and the RPM will not vary considerably as you state. More likely that the inaccuracy lies with the 3rd party software being used to work it out for the non ATC application you illustrate, which is not required to have the same accuracy as a regulated ATC system.

Its not really that inportant how accurate the RPM is, just so long as we know exactly where it is. Each rotation is digitised into 4096, reset at the North marker. If is doesn't count 4096 between Norths' then it throws an error. The RPM will change slightly due to wind loading, you can hear the head straining into the wind on a blustery day.

In the US overlapping approach radars will operate at different rotational speeds to prevent false locking of targets (not much different, just different)

Again , many thanks for the flow of info

10W , the rotation rate details are excellent , thanks.
This is all an unexplored area for us and the data here is helping to build the picture.

Tigersaw.... I have been experimenting with rotation against location and it confirms your comments re exact location....in a simlar way that for Planeplotters multilateration system we need pinpoint accuracy for our ground station location [ of which we now have over 300 ]

MarcK . . . I know our US users are having some difficulty . Whilst an FOIA revealed the site locations State by State , they are struggling with a lack of SI/II data.


Back here in the UK , some observations.

From our findings it seems that some Mode A/C sites are only operational at certain times.
I have an unknown site near Teeside which for example seemed to close down at the weekend.This leads me to think its possibly a little further south than I thought and may be Leeming

Some sites , such as Clee Hill give poor results no matter what we do . I suspect CH may be a cluster type array.

John

Clee 52 27 19.767 N
02 35 57.997 W Is that accurate enough for you? ;)

It's a Raytheon MK2A LVA Mode S Enhanced (dual channel) turning at 7.5 RPM on frequency 1030 Mhz.

BD

Many thanks BD

Thats the data I have , gleaned from our own survey . It uses the ident II 05 , but beam results can be a bit erratic which leads me to wonder if its used as a cluster site .
Surprisingly a/c only seem to respond to its interrogation when over the Scottish borders.

Sorry to be pedantic but it's Teesside. At the side of the Tees not the Tee.

A proper pedant would point out it was Durham Tees Valley Airport :)

No! To locals and those who work there, it's Teesside!

Ah,
RAF Middleton St. George.
Route direct to the Tango Delta. :ok:

So...is my unid Mode A/C radar head Teeside...Teesside .... Durham Tees Valley Airport....or somehwere else..? :ugh: :)

According to their company website, DTV Airport use a feed from Great Dun Fell and don't have their own SSR. I believe RAF Leeming do have one however, and it might make sense that it is turned off when there is no fast jet flying at weekends.

And the geography of that bit of the Pennines means that you can almost see the ground at Teesmouth from the top of GDF!

If you are building a "unique multilateration system", why do you need to know the position of interrogators? Other multilateration systems are able to use unsolicited replies without any knowledge of how they have been triggered or where from.

PlanePlotter already has a unique Mlat Wide Area network complete with its own Ground Stations , now numbering over 350 , across the UK and Netherlands.Thats been in place three years and works remarkably well.
Its also infinitely cheaper than NATS own very limited Mlat system , recently set up in the N Sea :eek:

However as the Mode-S messages carry the ident of the interrogating radar head we are now developing a further system which will support
Mlat in fringe areas.
We are also using Mode A/C pulses to add a second layer to this system.

Finally , by converting the Mode A/C data from non mode-S equipped a/c to sqwks we can then use those to attempt to locate Mode A/C only a/c too by comparing the pulse rates to those associated with Mode A/C ground stations.

I don't suppose a spotter's network like PlanePlotter has to worry too much about CAP670 and the various other regulatory requirements.

BD - you should know better!! :=

NATS doesn't give out the positions of the radar sites to anyone without a legitimate regulatory, security or safety reason. A FOIA request I suspect is pointless as NATS is a commercial company, not a government agency.

I would also suggest monitoring NATS transmissions for purposes they are not intended and using them for other applications, whether radar or voice, is probably not legal. See the sticky on the Main ATC front page http://www.pprune.org/atc-issues/206...tions-law.html

Given that Mode A/C only radars have to be turned off by the end of 2011 in the UK (be interesting to see how the CAA make that happen given UK MoD are massively behind), any system relying on Mode A/C is probably going to be of diminishing use.

But good luck :}

RS

Lets see what the CAA come up with

They have been prepared to give full information , including rotation speed and exact location of the sites in Scotland regarding the effects that wind farms might have on radar returns and that info is in the public domain.
Anyone with a GPS and a map can go and get a precise reading for each one....if they have the time , and also measure the rotation rate.
There are already NATS/CAA documents which give details of SI /II codes......its just that there isnt one definitive document listing all

As requested under FOIA 2000 regs the CAA has now provided a full list of UK radar stations including rotation rate SI/II whether Mode-S or Mode A/C [ or Both ] and exact location to 14 decimal places.:ok:

Now we can move on to the next phase.