Which UK ATC units have weather radar?

[Andy Rylance]

Out of interest which ATC units have weather radar? If you do have it what height can it see up to and how do you practically use it - is it overlayed on radar approach or a sep system/screen?

If you don't have weather radar does anyone know if any systems have been tried where aircraft weather radar data can be uploaded straight to the controller on a screen?

[PPRuNe Radar]

None of the UK Area Control Centres have weather radar overlays that I am aware of.

En route surveillance radars don't lend themselves to detecting weather due to the wavelength they transmit on, or is it the frequency ?? .... it's 25+ years since my Radar Theory course in my defence :). In any case, the display of weather at the controller's console would be generally pretty poor at showing anything relevant in the ACCs as the radar pictures are all processed to remove any clutter and to smooth target tracks.

[anotherthing]

Further to above by PPRuNe Radar (shouldn't RADAR be all capitalized :})

Having the overlay would IMHO not enhance the service we provided to aircraft. There is however a divided camp on this issue - some ATCOs like the idea of an extra toy to play with!

The reason I think it would cause more hinderence than help is due to many factors, some of which include the different SOPS that airlines, aircraft and even crews have regarding what weather return is acceptable to fly through and what isn't. I've had many instances where one crew asks to avoid yet a minute or two later another crew flies happily through.

Another reason is I firmly believe we are busy enough (I work in the LTMA but I speak for all controllers here - well maybe not the Luton approach guys :}) - I do not want to start second guessing what a pilot might or might not want to do - airspace is tight enough, I am not willing to give wild vectors just because in my opinion there is weather ahead.

It is the pilots responsibility, using his or her training coupled with the specially designed weather radar and mark one eyeball they have at their disposal plus their knowledge of company SOPs, to ask for deviance.

It is my responsibility, to either grant or refuse that deviance depending on the traffic situation, and also to keep all the aircraft under my control safe.

I will grant the deviance if it is safe to do so, but we have such tight confines that some weather avoiding in the recent past has entailed aircraft penetrating 2 or 3 other controllers sectors. This causes much work! As ATCOs we will alays try to allow deviance, sometimes it is not possible instantaneously due to conflicting traffic.

When aircraft start asking for weather avoidance, we put lots of restrictions in place on departures and arrivals, the restrictions get greater and greater the worse the weather becomes. This is all done to maintain safety whilst allowing aircraft to avoid weather.

If a pilot informs me that they have encountered bad weather, I will pass that on to the next one... however, invariably, the following crew already have a handle on it because they are monitoring their instruments (including the weather radar).

[JustaFew]

Radar is very good at one thing; measuring time. Who does what with the received signal depends on individual requirements.
Airfield primary radar will be either analogue or digital. The older analogue radar systems have a few filters; MTI, Moving Target Indicator, and/or LOG/CP.
MTI compares the latest received returns with previous returns over a set time period; if there is no change in position or strength, the return is not displayed. This removes clutter; high ground, buildings.
LOG/CP alters the transmitted signal between linear and circular, using a metal plate at the radar aerial to induce a helically-shaped pattern. A linear signal produces more reflections; increasing Circular Polarisation reduces the weather returns, as the signal passes through the weather less signal is reflected.
Digital radar removes clutter before it reaches the display, no weather is shown. A backward move IMO.

A rough guide to the vertical range of any radar is 1000ft for each 10 nautical miles from the radar head. Introduce terrain or buildings nearby, areas of shading will form. These are usually displayed on a chart at each unit for each radar,as radar equipment is flight checked before release into service.

It is possible, on analogue radars, to flick in and out of 'raw radar' (unfiltered) to see any weather. The disadvantage is that the radar won't show the base and top of said weather. As clouds have not yet been mandated to carry transponder equipment with mode C, even secondary radar won't show the base and top.

Perhaps a visit to a local radar-equipped ATC unit might help.

[djdruid]

Over here (Dutch civil ATC), scopes at our APP & ACC positions display digital weather information for the area around EHAM (extracted from an approach radar) or the FIR (supplied by our national weather service) - shaded according to intensity.

[BDiONU]

Have a search in this forum for your topic. The words 'weather radar' pull up several links.

BD

[321now]

anotherthing: Er, No....

The term has since entered the English language as a standard word, radar, losing the capitalization in the process. :)

[321now]

On the Marconi scopes there was a story about a BAC 1-11 pilot who asked Heathrow Approach to be vectored around some storm clouds.

The controller obliged and they proceeded to send the aircraft through the clearest parts of the weather that could be observed on the screen.

Turns out, the pilot later reported to Approach that it was some of the worst turbulence and icing the captain had ever experienced... (!)

Apparently, the storm existed but didn't show up on the radar console because the storm was moving too slowly, thus the MTI (moving target indicator) couldn't pick it up...

[Spitoon]

As far as I know there is no UK ATC unit that intentionally displays weather. As has been pointed out already, a lot of technology goes into building modern radars so that wx does not appear. As someone who has used an old 25cm radar I'll vouch for the usefulness of being able to switch out the filtering and look at wx returns on those few days of the year when wx really is a problem in the UK. By looking at the raw picture you could get an idea - but no more - of those areas that pilots might want to avoid. It was interesting that the position of heaviest wx on the ATC radar often did not correspond to the position of the heaviest wx on the aircraft wx radar - the reasons for this are fairly obvious but it demonstrates that simply overlaying a wx radar picture (without and additional level processing) does not always give useful information. Of course, when you have squall lines and other highly vertically developed met phenomena the info from ground and airborne radars will be more likely to agree.

In the UK the beancounters appear to win and any options to put weather onto ATC radar displays are turned down on a cost-benefit basis. On the days that it would be useful it is a great loss.

I seem to recall, maybe 10 or 12 years ago, there was a proposal to overlay data from a lightning detector system on Aberdeen's ATC radar. From what I remember, by the time the picture got displayed on the ATC picture it was about 20 minutes old and therefore would require a bit of trend analysis and crystal ball-gazing in order to be used. I'm not sure whether it was supposed to be an aid to controller situational awareness or a control tool meaning that you didn't use routes affected by lightning. As no-one from Aberdeen has mentioned it I presume that either the system did not go into operational use (at least not for long) or my memory is playing tricks on me.

[Data Dad]

Spitoon - The lightning display is operational at the Ice Station and has been for a long time.

As you say though the info provided is "old" data - up to 30 mins after the "strike". The accuracy of the position is also not good, I can't off the top of my head remember the book figures but we are talking miles out. Thunderstorms and lightning are actually rare events in this part of the world but when the radar shows lightning activity all we do is inform pilots that there is an indication of recent lightning activity in X-position (relative to themselves).

DD

[anotherthing]

321,

Caught me out - bugger!!

However, pedant mode on

I could argue that it depends whether you are using the word radar to describe an object in everyday english use, or RADAR to describe a process in technical language.

Pedant mode off.

I'm sure the use of either is correct, however in the context that I was asking PPRuNe Radar (tongue in cheek), I will concede that I was, technically wrong..

You could have Pm'd me though you git - no one else had picked up on it :}

[madlandrover]

As far as I know there is no UK ATC unit that intentionally displays weather.

I don't know if it's "intentional" or merely excellent controlling, but Bristol were pretty helpful recently advising me of weather ahead (in the event it was still flyable, but nice to know about!). Based on how accurately the controller described the position and extent it certainly sounded like a radar report - possibly from rainfall radar. Either way, yet another reason why they're a unit I'm more than happy to speak to nowadays :)

[Spamcan defender]

I too work LTMA and would say that having a toggleable wx overlay on the sector I work on would be an advantage. We have slightly more airspace than some sectors and I genuinely think it would be of benefit. Having the ability to toggle on/off allows those that DONT want it to be satisfied while alowing those that DO want it to be equally satisfied...

One for the safety prize methinks :ok:

Spamcan

[321now]

It's my ultimate ambition to work at TC, can't wait to get started in April. I'm on the next Appraoch Radar course at Hurn.

Do the TC approach units still use the NATS ACE software engine?

If they do, I was speaking to one of the engineers
who works with it (at Hurn).

He says there's no real flexibility in the software for such a tool, it'd cost an absoloute fortune to implement, and, logistically (from a programmers' point of view) It'd be a nightmare.

*shrugs*

[BDiONU]

I too work LTMA and would say that having a toggleable wx overlay on the sector I work on would be an advantage.
First thing you need to define is what you mean by 'weather' and the second thing is what are your requirements?
One for the safety prize methinks :ok:
If you can write down exactly what you want (simply stating a weather overlay is far too nebulous a concept) then I would concur with you winning the prize.

BD

[Sky Wave]

About 3 or 4 years ago now I remember being just south of the Isle of Wight, IMC enroute to Southampton in a PA28. The Solent controller advised me that I was heading towards some heavy weather and although he was unable to vector me around the weather he suggested that 20 degrees to the left may be a good idea! :ok:

So I guess Solent must have had some sort of wx capability?


SW

[Spitoon]

About 3 or 4 years ago now I remember being just south of the Isle of Wight, IMC enroute to Southampton in a PA28. The Solent controller advised me that I was heading towards some heavy weather and although he was unable to vector me around the weather he suggested that 20 degrees to the left may be a good idea!

So I guess Solent must have had some sort of wx capability?
There's a huge difference between having a primary radar with which weather returns sometimes get through the filters or can be displayed as a 'raw' picture if the controller chooses and having a picture of some sort showing the weather situation. This is why I said earlier 'As far as I know there is no UK ATC unit that intentionally displays weather'.

There are radars used by the Met Office to monitor the movement of weather - you can often see recent data from them on Met Office website (http://www.metoffice.gov.uk/weather/uk/radar/index.html). These radars, like all primary radars, detect rain - how well they detect rain depends mainly on the radar wavelength and the size of the water droplets. A lot of investment goes into ATC primary radars to supress the returns from rain etc. and to display the aircraft - but it's only partially successful, hence Southampton and Bristol (and any ATC other unit with a primary radar) will sometimes be able to give information about the weather derived from radar. For Met Office radars the investment goes into showing the rain and stuff.

I imagine that the original question related to having both pictures available to the controller, perhaps with the met radar overlaid on the the ATC picture.

Once again I would offer a few simple words of caution. A controller who can see some weather on the radar may offer advice to a pilot but there is no guarantee that what looks worst on the radar is in fact the worst area in the air.

[FragRad]

On our Watchman (10cm) with FRL displays, most of the weather is filtered out but fronts/Cb activity with heavy rain on often show through. If you select 'background video' it shows more and can often be of help in vectoring aircraft, particularly those without weather radar, around the worst of the weather. However, we quite often have pilots requesting weather avoidance around stuff we can't see at all and conversely, can offer weather avoidance around something we can see, only to have the crew quite happy to fly straight through it!

I was told recently that Warton have a weather radar overlay?

[anotherthing]

FragRad wrote

However, we quite often have pilots requesting weather avoidance around stuff we can't see at all and conversely, can offer weather avoidance around something we can see, only to have the crew quite happy to fly straight through it!........

And there lies the nub of the argument... let the crew do what they do best and let ATCOs do what they are paid to do - keep aircraft apart whilst endeavouring to let pilots do what they need to accomplish their task.

[JustaFew]

Think there's some confusion about primary radar. As I posted before, any and all primary radars do exactly the same; measure time accurately.
There are certain variables considered when designing a primary radar system such that one radar will be useless for a different application, even though a primary radar is used in both situations.
ATC use a primary radar for detecting planes; anything else is an added bonus/distraction for which designers build in various filters and constantly variable parameters. eg. staggered Pulse Recurrence Frequency, pulse length.
Any weather displayed on an ATC radar does not imply any weather radar capability; it is simply the radar doing what it is supposed to do. Detect reflections of a previously transmitted signal from that radar.

[321now]

The approach radar head at LHR is superb for weather, it's a DASA SRE-M8, the Germans use this with weather overlay... Why can't NATS??

[Spitoon]

The approach radar head at LHR is superb for weather, it's a DASA SRE-M8, the Germans use this with weather overlay... Why can't NATS??OK, now you're confusing me. You say the LL APP head is superb for wx - I presume you mean that it detects wx well. You then say that in Germany this radar is used with a wx overlay - which suggests that the wx data is derived from another radar.

321, I'm not sure what you're trying to say here but we seem to be getting into the realms of the possible combinations of radar sensor, processor (and plot extractor), data chain and display systems.

But to answer your last point - Why can't NATS?? Assuming that it's possible, and I've no doubt that from a technical perspective it could be done, the answer is quite simple £££££.

[Spamcan defender]

Quote:
Originally Posted by Spamcan defender http://www.pprune.org/forums/images/buttons/viewpost.gif (http://www.pprune.org/forums/showthread.php?p=3893083#post3893083)
I too work LTMA and would say that having a toggleable wx overlay on the sector I work on would be an advantage.

First thing you need to define is what you mean by 'weather' and the second thing is what are your requirements?

OK, I shall be more succinct....

By weather I mean active cells, thats all I, and I'm sure pilots, really give a toss about. If a Stormscope in a PA34 can do it then I'm sure some form of ground based equipment can do it too.

My requirements would be to have a big, and I mean fecking HUGE(at least 30sqmm), button marked 'WX' about 4" bearing 300deg from my comms switch which, when pressed, would magically display active cells in my sector as a nice red 'lightning' symbol about 5-7mm in length and about 3mm wide. Maybe even make the symbol waggle about a bit so I can see it. If I press the button again I want to make it all go away......:E:E

Hows that for succinct???? :8:8:8

Spamcan

[BDiONU]

By weather I mean active cells, thats all I, and I'm sure pilots, really give a toss about.
So you don't want to see 'weather' you want to see CB's?
display active cells in my sector as a nice red 'lightning' symbol about 5-7mm in length and about 3mm wide. Maybe even make the symbol waggle about a bit so I can see it.
Just off the top of my head what mitigation would there be for targets which were obscured by this symbology? What would you (and pilots) expect to be able to do with this, vector aircraft around it without asking if the pilot would wants to be vectored around it? Make ATC responsible for weather avoidance in addition to traffic avoidance?
IMHO anotherthing nails the problem, irrespective whatever the cost and technology required might be in providing a real time CB overlay.

BD

[Spamcan defender]

Just off the top of my head what mitigation would there be for targets which were obscured by this symbology?

None!!! Everyone knows if you cant see the target its not there :E:E

Seriously though, I appreciate what your saying there and accept that Wx overlays are probably more trouble than they're worth. I suppose, in all fairness, the present situation is fine with pilots telling us what they would like to do avoidance-wise.

It might be more feasible to configure one of the auxiliary displays at the radar suite to show the WX as displayed on the monitor at the GS desk (TC)

Thats probably a mich better idea.:ok:

Spamcan

[BDiONU]

It might be more feasible to configure one of the auxiliary displays at the radar suite to show the WX as displayed on the monitor at the GS desk (TC)
Do you remember yea olde TClipper board from West Drayton? Thats being resurrected at Swanwick and your suggestion should be put to it. Or you could try and win an iPOD by putting it forward as a Safety Idea.

BD

[Spamcan defender]

Or you could try and win an iPOD by putting it forward as a Safety Idea.

I'm sure tongues would wag if I won a SECOND Ipod :ok::ok::}

Although I shall consider putting the idea forward.

Spamcan

[Bring back Tridents]

Ahhhh, Marconi 264s. Now there was a radar. Blips the width of an airway and tangential fade on base leg.:uhoh: <emotion filled sigh> They were great for showing weather but I seem to remember you had to switch the MTI off to do it. Our current Watchman has the rather annoying habit of producing lots of primary returns that might be weather or might be windfarm turbines. Don't think I'd like to have weather shown as an overlay.

[Spitoon]

Marconi 264s. Now there was a radar. Blips the width of an airway and tangential fade on base leg. <emotion filled sigh> They were great for showing weather But the Marconi only showed really bad weather. If you wanted to see weather you needed a Plessy 424 or 430. They were great, just when you needed them all you could see was the the darned wx clutter. Doing an SRA to half a mile was an art. Eee, by gum, thems was a man's radar!

Ok, apologies to the ladies who used them too, including one who taught me how to caress the 424 control unit to get the best out of it!

[henry crun]

In my experience the 264 could, within limits, show whatever wx you wanted it to, it just depended on how your techs set it up and whether or not the MTI was in or out.

[Bern Oulli]

Ah! The 430. Best weather radar ever. Absolute cr@p for SRA's in bad weather I would agree. Now the Decca 424 was definitely the dog's dangly things. All valves and stuff. Tune for maximum smoke and you could hit the touchdown zone markings every time. Happy days.:)