[jhb_airlines] Re: Please refresh these old brain cells

  • From: "Mike Brook" <mike.brook@xxxxxxxxxxxxxx>
  • To: <jhb_airlines@xxxxxxxxxxxxx>
  • Date: Tue, 23 Sep 2008 22:28:46 +0100

Bones -

That is absolutely fascinating!  Thank you for the time and effort that went
into that update, I can safely say that it is all now crystal clear and I
can well understand why it has taken up so much of your time recently <g>.

From a safety point of view, both systems appear to represent major steps
forward, particularly with regard to easing the future ATC burden.  I'm all
for progress.

Thanks again for explaining the project so lucidly.

MikeB

p.s. I want one ...  !

> -----Original Message-----
> From: jhb_airlines-bounce@xxxxxxxxxxxxx [mailto:jhb_airlines-
> bounce@xxxxxxxxxxxxx] On Behalf Of Bones
> Sent: 23 September 2008 21:55
> To: jhb_airlines@xxxxxxxxxxxxx
> Subject: [jhb_airlines] Re: Please refresh these old brain cells
> 
> It's coming up to three years since I got roped in to the SBS testing
> and
> with another unit about to be released it's getting busy again. Luckily
> the
> software that was under development since last November has finally
> gone to
> public beta and I've finally had a bit of a rest the last two or three
> weeks.
> 
> It's hard to describe the kit in a nutshell so I fear this may be a
> long
> post. At least I'll include some pretty pictures.
> 
> Mode S transponders are slowly replacing Mode C units. This has been on
> the
> cards for a while because we are running out of squawks to allocate to
> aircraft. The future is squawkless because with the new Mode S system
> each
> aircraft has a unique code embedded in the transponder.
> 
> With the Mode C unit you know that a pulse from a ground radar triggers
> the
> transponder to reply. That reply is just a four digit code (the squawk)
> plus
> height data. When we get this code our code converter replaces the
> squawk
> with a callsign, plus anything else we might need (type, destination).
> In
> other words the data is mostly in the ground radar databases and
> requires
> constant updating. Aircraft showing a unique squawk like 4551 can
> display
> the callsign on screen but the dozens of aircraft coding 7000 or 2000
> cannot
> be identified - we just see the height for these unknown aircraft.
> 
> With Mode S each aircraft is given a specific code which is set in the
> transponder on installation - in other words the pilot can't touch it.
> The
> whole worldwide range is from 000000 to FFFFFF with each country being
> given
> a code block to allocate. In the UK we have 400000 to 43FFFF which we
> have
> to subdivide for military aircraft and those of the overseas
> territories
> like Bermuda, Cayman and the Isle of Man.
> 
> Mode S transmits little more than Mode C - code, callsign and height -
> but
> because all Mode S codes are known it means every radar system
> worldwide can
> use the same database to convert the Mode S code to a Registration,
> type and
> owner. For example go to Airframes at http://www.airframes.org/ and
> type in
> the code 400CB6 and it will give you full data on that aircraft.
> Peter's
> C172 G-GYAV may not yet be fitted with Mode S but it has already been
> allocated a code of 402991. The addition of a callsign is very useful
> because most airliners have the Mode S hooked up to the FMS and so we
> can
> see the callsign as well as the registration (if we need the latter).
> Other
> than this basic difference Mode S is not really much different from
> Mode C
> as it still needs a conventional radar to pinpoint the location of the
> aircraft.
> 
> OK - take a bit of a breather...
> 
> On we go..
> 
> As Mode S evolved it became clear that the system had the capability of
> sending more data than just code, callsign and height. On a trial in
> Scandinavia (and another in Alaska) they fitted aircraft with extended
> squitters that could send height, groundspeed, IAS, track, heading,
> position, rate of climb and what the pilot had for lunch. This system
> is
> called ADS-B and you can see its potential because it makes all ground
> based
> radars redundant. Again, this data is sent every second and being
> general
> broadcast can be picked up, not just by ATC but anyone with a receiver.
> In
> the trial all aircraft had such receivers so all had a complete radar
> picture of all other aircraft in a radius of approximately 500nm. Not
> only
> that but the system was further tweaked to provide TCAS warnings on
> such
> aircraft. Powerful stuff. Even further testing saw Mode S transponders
> being
> fitted to vehicles that regularly move on taxiways and runways - and
> with
> this level of use almost any airfield could operate such a system and a
> Tenerife type accident would become impossible to repeat except through
> downright stupidity.
> 
> So we need to know two terms here - Mode S and ADSB.
> 
> Mode S is slowly being implemented and mandatory carriage is slowly
> coming
> in. In a sense it's daft because the CAA are way behind with their Mode
> S
> radar installations and so all aircraft so equipped don't yet see any
> advantage in having fitted the kit. ADSB isn't yet mandated for
> carriage by
> aircraft and it is likely to be a further decade before it does. Having
> said
> that something rather unprecedented is happening in aviation in that
> many
> aircraft are already installing full ADSB and that before any
> legislation
> has even been considered about fitting it. To give you an example I can
> currently see 86 Mode S aircraft on my screen and 47 of these are full
> ADSB.
> 
> OK - that's the lecture out of the way, now on to the system.
> 
> The SBS receiver I use comprises of a decode box and a small aerial
> just 6"
> high.
> 
> Aerial - http://www.homepages.mcb.net/bones/WebPost/SBS_Aerial.jpg
> SBS Box - http://www.homepages.mcb.net/bones/WebPost/SBS_micro.jpg
> http://www.homepages.mcb.net/bones/WebPost/SBS_micro1.jpg
> http://www.homepages.mcb.net/bones/WebPost/SBS_micro2.jpg
> 
> The box feeds raw aircraft data to the PC via USB or Ethernet (Wireless
> via
> a suitable router). The software converts this to useable data and (for
> ADSB
> aircraft) a position on a radar screen. The data flow is immense as
> each
> aircraft sends a pulse every second. For 100 aircraft that's 360,000
> messages per hour or 8.6 million per day!
> 
> The BaseStation software looks like this:
> 
> http://www.homepages.mcb.net/bones/WebPost/BaseStation.gif
> 
> That shot was taken at 1824 tonight so it's about as current as I can
> get.
> For a neat animated GIF from another user see
> http://www.coaa.co.uk/PPanim.gif
> 
> On my screen you have the radar view on the left showing all ADSB
> contacts
> and on the right is the aircraft list showing all contacts. I'm lucky
> in
> that I have extremely good coverage as the signals are 1090GHz and very
> much
> line of sight - fortunately I don't have many obstacles or high ground
> around me, apart from a bloody sycamore which I'm sorely tempted to
> accidentally run a JCB into.
> 
> The radar screen can be set up to show many different views. If you
> have
> good coverage you can set up several to flick between important areas
> or
> different magnifications:
> 
> UK - http://www.homepages.mcb.net/bones/WebPost/ZMMS2.gif
> Irish Sea -  http://www.homepages.mcb.net/bones/WebPost/SBSViewer.gif
> Shawbury - http://www.homepages.mcb.net/bones/WebPost/ZZCL.gif
> Manchester Zone -
> http://www.homepages.mcb.net/bones/WebPost/ZZRoute1.gif
> Atlantic rush - http://www.homepages.mcb.net/bones/WebPost/ZZTS.gif
> Doncaster - http://www.homepages.mcb.net/bones/WebPost/Doncaster.gif
> Dublin - http://www.homepages.mcb.net/bones/WebPost/Label4.gif
> 
> 
> Sometimes we get ducting and can see aircraft well below the nominal
> horizon. Theoretically I shouldn't see aircraft over Manchester or
> Dublin
> below 5000ft but:
> 
> Departure from EGCC at 700ft -
> http://www.homepages.mcb.net/bones/WebPost/DuctEGCC.gif
> Aircraft on ground at Dublin -
> http://www.homepages.mcb.net/bones/WebPost/DuctEIDW.gif
> 
> You can also export the data to Google Earth and see the aircraft in
> 3D!
> http://www.homepages.mcb.net/bones/WebPost/GE2.gif
> 
> As I said before I have pretty good range on my system (although
> limited
> northwards by the hills):
> http://www.homepages.mcb.net/bones/WebPost/Z240.gif
> 
> Range is really a factor of location and if you live in a valley or a
> basement apartment in a 24 floor block of flats it's going to kill your
> fun.
> You don't want to live in Keighley as one of our users does:
> http://www.homepages.mcb.net/bones/WebPost/ZZCH2.gif - he can barely
> get
> 40nm range on his box.
> 
> 
> I won't go into the screen display in any detail but you can see it is
> infinitely tweakable. Some shots have labels on, some off. Some have a
> height filter, some have four line aircraft data tags (Manchester Zone)
> but
> others show much less information - I'm currently using just two lines
> to
> reduce clutter.
> 
> Moving on..
> 
> The display on the right of the screen shows all current aircraft
> detected:
> http://www.homepages.mcb.net/bones/WebPost/LOGOS.gif
> 
> Again this table is infinitely variable and mine only shows a fraction
> of
> the columns you can display. I've shifted columns around too so you
> will see
> different layouts in the shot above and my current display. Note the
> first
> column showing the symbols. Full ADSB have an aircraft symbol and Mode
> S
> only show as a dot or four dots. After the airline logo you will see
> the
> Mode S code for each aircraft (notice there is a miscode in my first
> shot)
> followed by the callsign as being sent by the aircraft.
> 
> If you double click on any aircraft in the list it brings up a further
> window showing more detail. In my case I've tweaked the XML code for
> this to
> show more than was originally provided - including pictures:
> http://www.homepages.mcb.net/bones/WebPost/AD51.gif
> http://www.homepages.mcb.net/bones/WebPost/List2.gif
> 
> 
> Enough of the technical side. As far as it goes I think the kit is
> brilliant
> - I'd always hoped that ADSB would be mainstream ATC before I retired
> but
> it's way behind schedule. SBS allows me to see what I had hoped would
> be the
> future for ATC. I'm staggered by the range it goes out to - our
> Watchman
> barely hits 80nm and the SBS is four times that distance. The
> electricity
> bill between the two is laughable. The other major advantage is that
> the
> refresh rate of Mode S is once a second -four times faster than a 15
> rpm
> radar head. This is a serious limit for radar talkdowns as a four
> second
> sweep doesn't allow rapid action if things go wrong. That is why most
> SRA's
> are terminated at 2nm from touchdown.
> 
> In pure usability terms is the SBS a good tool for spotters? In essence
> (and
> with reservations) I'd say yes because your spectrum of data is
> massively
> increased and your conception of traffic flow is far greater than
> trying to
> picture it by listening to a scanner. It's fascinating seeing traffic
> stuck
> in the London holds
> (http://www.kinetic-
> avionics.co.uk/imagepopup.php?images/Bscreen_shot.jpg)
> or on approach to an airport (if you are in line of sight of one).
> 
> The real question is whether it shows the traffic you are interested
> in. As
> a rough guide you can expect most jet fleets to carry full ADSB,
> especially
> long haul. Short haul jets are a mix with all Ryanair, BAW, BMA,
> EasyJet and
> European national airlines carrying it - but then you get FlyBe who
> refuse
> to have anything to do with it and all their aircraft are Mode S only.
> Likewise it's rare to see any turboprops with full ADSB, just Mode S.
> Light
> aircraft are a mixture - many are now moving to Mode S and we see them
> in
> the list but just as many are waiting until the final deadline before
> kitting up. Having said that I notice a good dozen or so new GA
> aircraft
> coming on my list each week. No GA aircraft seem to have full ADSB kit
> -
> with the exception of G-BRZS, a Cessna 172 at Blackpool. I don't know
> where
> he got the kit from but it is definitely full ADSB as I often see him
> trundling over to Caernarfon from Blackpool and back.
> 
> Most military aircraft have full ADSB but they encode the position data
> and
> we only get height and speed information - no location. They seem to be
> fitting kit by unit as we suddenly get a bunch of Leeming Hawks on
> screen
> where we'd seen nothing before. Most VC10, C130, Tornado, EuroFighter
> show
> up now but I've never picked up any Valley Hawks or any Tucanos.
> 
> As the box is an expensive bit of kit it's important to consider your
> needs
> before buying. If it is just local aircraft then you may be
> disappointed -
> you won't see lots of light aircraft flying into Wolverhampton but
> you'll
> see lots of airline traffic going into Brum.
> 
> Bit of advice. If you are interested in the kit wait a little while. A
> new
> SBS-1e unit is coming out in November and I suspect some users will
> want to
> upgrade. If so expect to see a bunch of SBS Mk2 units coming up on Ebay
> and
> this should drop the price down.
> 
> I bet you wish you have never asked.. ;)
> 
> bones
> bones@xxxxxxx
> http://woodair.net
> 
> 
> -----Original Message-----
> From: jhb_airlines-bounce@xxxxxxxxxxxxx
> [mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Brook
> Sent: 23 September 2008 17:03
> To: jhb_airlines@xxxxxxxxxxxxx
> Subject: [jhb_airlines] Please refresh these old brain cells
> 
> Bones -
> 
> I've totally lost track of your extra-curricular activities re the
> hardware/software tracking kit that you are using/testing. Could you
> please
> provide a status/update regarding what it is and what is happening with
> it?
> (If you understand what I mean ... <G>).
> 
> TIA
> 
> M.
> 
> > -----Original Message-----
> > From: jhb_airlines-bounce@xxxxxxxxxxxxx [mailto:jhb_airlines-
> > bounce@xxxxxxxxxxxxx] On Behalf Of Bones
> > Sent: 23 September 2008 16:45
> > To: jhb_airlines@xxxxxxxxxxxxx
> > Subject: [jhb_airlines] Re: Next VFR Trip
> >
> > Yes - that was bad luck. Fortunately it made the Southport show
> despite
> > atrocious weather and also Goodwood and Silverstone last weekend.
> >
> > Luckily the Vulcan has Mode S so it's easy to keep track of. As of
> last
> > month the BBMF also have Mode S on the Lanc and two Spitfires. I've
> yet
> > to
> > pick these up.
> >
> > bones
> > bones@xxxxxxx
> > http://woodair.net
> >
> >
> > -----Original Message-----
> > From: jhb_airlines-bounce@xxxxxxxxxxxxx
> > [mailto:jhb_airlines-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Brook
> > Sent: 23 September 2008 16:23
> > To: jhb_airlines@xxxxxxxxxxxxx
> > Subject: [jhb_airlines] Re: Next VFR Trip
> >
> > Following the railway, no doubt.  I was SOOOO upset not to have seen
> it
> > t'other week at Shoreham  8-(
> >
> > M.
> >
> 
> 
> 




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