In myflights how do you get aircraft to show on ground at 0 ft.
Ian
Hi Ian,
In preferances - Radarbox change the QNH setting to your chosen airfield QFE.
HTH Cheers John
Quote from: EGNXR on June 24, 2009, 05:28:57 PM
Hi Ian,
In preferances - Radarbox change the QNH setting to your chosen airfield QFE.
HTH Cheers John
Hmmm... not sure i understand that .
Ive looked in preferences and cant see how .
any chance of an idiots guide ?
cheers
Quote from: aps on June 25, 2009, 08:34:45 AM
Hmmm... not sure i understand that .
Ive looked in preferences and cant see how .
It's tucked away, rather confusingly, under
File -> Preferences -> RadarBox -> Transition Altitude. Don't forget you will have to adjust the value regularly, as the barometer changes, to keep aircraft displaying zero altitude on the ground.
I would assume that you also need to untick "Auto Set QNH" in SmartView (otherwise, if you have an airport selected, its METAR QNH will presumably override the value you have set in Preferences).
[Suggestion for V4.0 - either allow the user to specify a QNH adjustment, or use the Elevation value for the selected airport, to derive an estimated QFE value automatically]
Hi Ian,
Not much I can add to Dave's explanation, but one thing I have noticed is while at an airport you can get 0ft showing but from home you tend to get slight variations +/- a few feet. As in screenshot below.
Cheers John
Quote from: EGNXR on June 25, 2009, 03:17:35 PMone thing I have noticed is while at an airport you can get 0ft showing but from home you tend to get slight variations +/- a few feet.
I think the reason for that is that aircraft transmit their altitude to the nearest 25' or 100' (depending on the fit). So the value adjusted for QFE can still be out by up to 50 feet.
However once the ground bit is set in the Flight Status then I believe both RB and SBS display a zero value, though I can't be sure as I'm too far from any airport to be able to pick up aircraft on the ground.
Dave
Would it not be possible for you to look at my aircraft at STN via the network. There is a Ryanair at the hold for takeoff. Showing 345feet. You should see it with 5 minutes delay, presumably.
Dudley
Quote from: dudbaker on June 26, 2009, 01:31:46 PMWould it not be possible for you to look at my aircraft at STN via the network. There is a Ryanair at the hold for takeoff. Showing 345feet. You should see it with 5 minutes delay, presumably.
Didn't read your post in time to look for it, I'm afraid.
It wasn't EI-DAV, by any chance ?
Dave
EI-DAV was around at 1540 so a bit latter. The one I indicated was just an example: there are many others to help clear up the point. I wonder if there is a EI-DUD.
Dudley
Quote from: dudbaker on June 26, 2009, 03:45:56 PM
Dave
EI-DAV was around at 1540 so a bit latter. The one I indicated was just an example: there are many others to help clear up the point. I wonder if there is a EI-DUD.
Dudley
Hi Dudley,
Yes = EI-DUD B752 Kras Air/Air Union (ILFC)
There used to be an EI-EIO Not sure if it was owned by Old MacDonald thou' ;-)
Cheers John
Hmmmm. im pretty much still only getting stuff above say 200ft ish landing and taken off
Plus in the transition altitude i cant get it below 800 ft ... thats if im understanding it correctly... top line(1000) & bottom line(800) ?
MAN is only 2miles from me as the crow flies too....
Tony
APS
I hope you are allowing for MAN being 275 feet above sea level. So 200 feet ish would be fine with QNH set. Are they over the airfield at this height.
Dudley
Quote from: dudbaker on June 27, 2009, 01:00:25 PM
APS
I hope you are allowing for MAN being 275 feet above sea level. So 200 feet ish would be fine with QNH set. Are they over the airfield at this height.
Dudley
Thanks Dudley , no i didnt !
please forgive my stupidity but what do i enter into which altitude box ?
Just looking at it again ... simply ... i have no clue what to do !
Tony
Quote from: aps on June 27, 2009, 01:53:08 PM
Quote from: dudbaker on June 27, 2009, 01:00:25 PM
APS
I hope you are allowing for MAN being 275 feet above sea level. So 200 feet ish would be fine with QNH set. Are they over the airfield at this height.
Dudley
Thanks Dudley , no i didnt !
please forgive my stupidity but what do i enter into which altitude box ?
Just looking at it again ... simply ... i have no clue what to do !
Tony
You may be making life more difficult than it needs to be :-)
Civil airliners use the QNH pressure setting (do a Wiki search - it's a complicated subject) and therefore their altimeters will show the airfield elevation when landing, not zero feet. RadarBox automatically sets the QNH for the airfield you select in SmartView if you have Auto Set QNH ticked in SmartView, so you will always get an altitude readout that corresponds to what air traffic are telling the pilot to do. If you have RB showing you the height above the airfield, then this will not make any sense when listening to air traffic.
I believe that the Mode S transponder on the aircraft is supposed to send a zero height readout when on the ground, but this doesn't seem to be the case, unless it is a signal that RB is not trapping.
Quote from: Allocator on June 27, 2009, 02:10:51 PM
Quote from: aps on June 27, 2009, 01:53:08 PM
Quote from: dudbaker on June 27, 2009, 01:00:25 PM
APS
I hope you are allowing for MAN being 275 feet above sea level. So 200 feet ish would be fine with QNH set. Are they over the airfield at this height.
Dudley
Thanks Dudley , no i didnt !
please forgive my stupidity but what do i enter into which altitude box ?
Just looking at it again ... simply ... i have no clue what to do !
Tony
You may be making life more difficult than it needs to be :-)
Civil airliners use the QNH pressure setting (do a Wiki search - it's a complicated subject) and therefore their altimeters will show the airfield elevation when landing, not zero feet. RadarBox automatically sets the QNH for the airfield you select in SmartView if you have Auto Set QNH ticked in SmartView, so you will always get an altitude readout that corresponds to what air traffic are telling the pilot to do. If you have RB showing you the height above the airfield, then this will not make any sense when listening to air traffic.
I believe that the Mode S transponder on the aircraft is supposed to send a zero height readout when on the ground, but this doesn't seem to be the case, unless it is a signal that RB is not trapping.
Still not what im asking ..
Ahh well... i think its time to give up trying to see a/c on ground .
thanks anyway
Tony
OK Tony, here you go:
- find an aircraft on the ground, say the altitude readout is 300 ft - I think that you want it to read zero feet?
- First of all, click on the SmartView Tab to the right of MyFlight and Network. Where it says 'Auto set QNH' make hure that the box is NOT ticked
- Goto the RadarBox File menu item at the top left of the screen
- Left click on File and then left click on Preferences and then on the RadarBox tab in the Preferences window
- Look down to the Transition Altitude section middle left of the window.
- Set the 'Above this value altitude etc' and set 6000 here
- Go to the box below where it says 'QNH (to display etc')
- Divide the height you are seeing the aircraft on the ground by 30 (in our example we said that the aircraft was showing 300 ft on the ground) so 300 divided by 30 = 10
- Whatever figure you have now in the QHN box, say 1016, subtract 10 from this = 1006
- Enter this figure in the QNH box and click Apply and OK to exit the Preferences menu
- The aircraft that was reading 300 ft on the ground SHOULD now read zero
You will have to do this every day an the pressure changes all the time. You might even need to do this more than once a day if the pressure is changing rapidly.
Give it a go and see how you get on :-)
Allocator
I have just checked 737 ops manual. Pre Take off Transponder ON. Shutdown Transponder SBY/OFF. I have been retired 4 years and things move fast in aviation. I used to teach that there is a customer option. Transponder on off can be operated by weight on ground switch. A magazine recently suggested it can be landing position operated. I have no knowledge of zero being sent on the ground but of course possible.
Dudley
Thanks Dudbaker,
I read somewhere that there is a separate transponder message activated by 'weight on wheels' that can be decoded to show that the aircraft is on the ground. I also read that RB doesn't decode this, so there is no 'on the ground' indication. I'm sure somebody here will know the technical details, so I'll wait to be educated :-)
Allocator
This may be true but it will only apply during Taxi. ATC get the right hump if the crew leave it on. Joe Soap had to go out and find which one it was.
Dudley
Thanks Allocater , very helpful ....
Alas as usual with things its still confusing me !
Aircraft on the ground ... found .... altitude -1050 !! which goes against everything which im led to believe.
honestly , ive given up.
Tony
Quote from: aps on June 27, 2009, 04:13:44 PM
Thanks Allocater , very helpful ....
Alas as usual with things its still confusing me !
Aircraft on the ground ... found .... altitude -1050 !! which goes against everything which im led to believe.
honestly , ive given up.
Tony
No problem just add 35 to the figure you have set in QNH.
1050 divided by 30 = 35
As I said before, you really are trying to complicate matters. The correct option is to make sure that the auto set QHN is ticked in SmartView and that the airfield is entered in the 'Select Airports' box in Smartview - everything is then automatic and you will see what the controllers are seeing when the aircraft is airborne :-)
Remember, pressure changes all the time, as you will see if you watch a barometer - and an aircraft altimeter is really only a very expensive barometer. Now imaging flying an aircraft using a barometer to show you how high you are and you will get an idea why air traffic controllers and pilots get so excited about having the correct pressure set!
Quote from: dudbaker on June 27, 2009, 03:45:03 PMI have no knowledge of zero being sent on the ground but of course possible.
There is no provision in the Mode S spec for sending QFE-based or QNH-based altitudes, so aircraft on the ground will still send altitude based on 1013.2mb, which is unlikely to be zero.
However the aircraft's response to any Mode S interrogation also contains a set of Flight Status bits, one of which can be used to indicate whether the aircraft is either airborne or on the ground. Applications using this data can of course make use of this status bit to force display of a zero altitude. Whether RadarBox or SBS/BaseStation actually do this, I don't know - not being close enough to an airport to pick up aircraft on the ground.
HTH
Dave
Looking on the network right now , there are several aircraft at Heathrow showing ground at 0ft.
Ian