Primarily for general aviation discussion, but other aviation topics are also welcome.
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By GrahamB
#1664307
Are we not getting rather anal about accuracy here?

We don’t expect radar controllers to provide us with ‘Traffic in your 23 minutes past 11, range 4 miles plus or minus one half of a mile, tracking left to right, indicating 1000’ below, plus or minus 200’, radar error represents an angle of 4 degrees at that range’.
skydriller, neilmurg, Nick liked this
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By neilmurg
#1664316
GrahamB wrote:Are we not getting rather anal about accuracy here?
Pilots, anal? You'll be saying OCD next!
Ever since the mid 80's when it became trivial to produce professional looking presentations there's been an issue with presentation exceeding the quality of the information. And thanks, I haven't had chance to ride that hobby horse in a while :)
I like the [edit]verbal[/edit] annunciation of targets, there's less implied accuracy and no heads down required.
Last edited by neilmurg on Thu Jan 10, 2019 10:27 am, edited 1 time in total.
Flyin'Dutch', kanga liked this
#1664320
This is a sort of GPS CYA isn't it? Surely we all "know" that the GPS position is going to be accurate to within a few metres at all times. We don't have selective availability any more and even if we did, it would only be out by a hundred metres or so.
#1664324
@gaznav
Looking at your original posting (and measuring on google maps), it would appear that the following ADS-B Aircraft are sending a NACp of the following values

Code: Select allG-BDFR // NACp=2.0nm
G-HMCF // NACp=2.0nm
G-EDGA // NACp=10.0nm


I think we need to understand why these numbers are so poor

As @Paul_Sengupta says, GPS is rarely that bad, so it sounds like a possible interpretation error either at the Transmission end (to be determined) or at the receiver end, SkyEcho2

Thx
Lee
kanga, gaznav liked this
#1664355
Nick wrote:All you need is a red dot or something to tell you to scan over there.

I think I will stick to my Butterfly display.

Nick


I agree , I think a totally separate dedicated display for EC is needed.
EC on a Nav display is too much confusion.
Nick liked this
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By ls8pilot
#1664361
Shoestring Flyer wrote:
Nick wrote:All you need is a red dot or something to tell you to scan over there.

I think I will stick to my Butterfly display.

Nick


I agree , I think a totally separate dedicated display for EC is needed.
EC on a Nav display is too much confusion.


I agree, a small 2 inch display like the lxnavigation flarm display is ideal - easy to mount and clear.

Just need one that will talk wireless and take GDL 90 protocol

http://www.lxnavigation.com/flarm/flarm ... display-2/
Shoestring Flyer, Nick liked this
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By Tim Dawson
#1664362
Nick wrote:All you need is a red dot or something to tell you to scan over there.


It's not that simple. Let's say you hear from an aircraft which says it's two miles ahead of you at 2 o'clock, but that position has an uncertainty of 5 miles. So it might actually be on your left. Would a vocal annunciation telling you to look at 2 o'clock be helpful?
User avatar
By Tim Dawson
#1664373
If it transpires that for ADS-B outputting aircraft the uncertainty is usually pessimistic, and that actually the aircraft is usually just about where it says it is, I agree it would be helpful.

However a complication is that PilotAware are proposing to use this same flag for another purpose, which is to represent the uncertainty inherent in a multilaterated position. In that case, it might be as likely as not that the aircraft is actually on your left when it's reporting it's on your right. There isn't much evidence at this point.
kanga, gaznav liked this
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