SkyDemon Forums

Traffic Voice Alerts and Pilot Aware

http://forums.skydemon.aero/Topic27756.aspx

By fokus - 2/12/2019 11:50:43 AM

Tim Dawson - 2/12/2019 10:34:44 AM
The most we can say about a bearingless target is "there's something somewhere, probably within ten miles, at an altitude close to yours". We do not judge that to be useful; quite the opposite. The great strength of our vertical traffic information is how little it talks to you, because it's clever enough to know what is worth talking about. If we announced every bearingless target it would be talking a great deal.

I'd like to here i.e. " attantion - beraringless target" if there is one close to me. Just to "wake me up" and have a look onto the screen and have a look outside.
By PaulSS - 2/12/2019 2:01:49 PM

"If we announced every bearingless target it would be talking a great deal."

You obviously know a lot more about it than me but is this really the case? I haven't heard of anyone reporting a great deal of talking right now and bearingless targets have been around for some time now. I do realise the vocal audio is a new feature to SD but there certainly does not seem to be people complaining about the number of bearingless target warnings they are getting from PAW audio.

I do understand your reasons for not wanting to give the 'intelligent' voice warnings you have designed for the other traffic but, as suggested by Peer, I think it would still be useful to give some sort of aural indication that bearingless targets have been detected and draw your attention to the screen to make your own determination.
By Tim Dawson - 2/12/2019 3:29:57 PM

Peer, the trouble is, we don't know if there is one close to you. We have no idea how close it is. It might be an airliner taking off 25 miles away or a microlight right next to you.

We will avoid creating text-to-speech output for bearingless targets in the first release, for sure. We'll just see how it goes. We are not regular users of PilotAware ourselves so we are not familiar with how often that particular system tells the pilot about one of these targets.
By c182driver - 2/13/2019 4:34:23 PM

I agree that bearingless targets can be confusing and too intrusive but some of that can be mitigated by setting the filter on PAW to ultra short range or perhaps just short-range. 

The bit that is actually very helpful is the vertical separation. Yes, it may mean that I am descending to avoid an aircraft that is announced to be 200 feet above me which is, in fact, 5 nm or more away, but I'd rather err on that side than the alternative. 

By not having the equivalent audio alerts to PAW in the SD version, it means that some of us who would much prefer to take advantage of SD's 'smarter' audio traffic alert algorithm might decide not to. If the former were included, I know that I for one would not hesitate to use the SD version and enjoy, as it were, the best of both worlds! 
By MarkusM - 2/13/2019 6:32:20 PM

Since there is no knowledge on the transmitting power, the estimation algorithms no longer work. We have seen similar with the gorgeous Monroy devices, which became almost useless when modern transponders mixed with older ones. Today there is no way to guesstimate the distance to the source.
By c182driver - 2/13/2019 7:43:54 PM

I'm not sure I understand. I'm talking about vertical separation (or distance) of bearingless traffic based on target Mode C readouts, not horizontal distance which I know is essentially meaningless. 

Are you saying this doesn't in fact work? That is not at all what PAW claim - the very reverse in fact. 
By tnowak - 2/14/2019 8:27:09 AM

MarcusM is just stating that there is no way to meaningfully differentiate between:
1. A high power Mode C transponder transmission from a CAT aircraft, say 50 miles away
2. A low power Mode C transponder transmission from a GA aircraft that may be just 1-2 miles away.
Yes, you can filter transponder returns by altitude but if you are flying in a busy environment it could be confusing/misleading as to what the true threat is.
Tony



By grahamb - 2/14/2019 8:35:45 AM

If only people would focus their attention, and budgets, on -being- conspicuous rather than trying to see every last piece of traffic on their tablets, the situation would soon resolve itself. ;-)



By Tim Dawson - 2/14/2019 11:04:43 AM

Very wise words, Graham!
By neilmurg - 2/14/2019 6:08:34 PM

tnowak - 2/14/2019 8:27:09 AM
MarcusM is just stating that there is no way to meaningfully differentiate between:
1. A high power Mode C transponder transmission from a CAT aircraft, say 50 miles away
2. A low power Mode C transponder transmission from a GA aircraft that may be just 1-2 miles away.
Yes, you can filter transponder returns by altitude but if you are flying in a busy environment it could be confusing/misleading as to what the true threat is.
Tony




No way? Is that a conclusion after analysing the PAw algorithm?
For instance, how quickly could the strength of a signal from 200 miles away change, aircraft doing 140-250kn, vs a signal from 5 miles away @120kn?
By c182driver - 2/10/2019 3:40:46 PM

I'm looking forward to the new traffic voice alerts on the next release. As a Pilot Aware user, this will presumably mean disabling PAW's own voice alerts in favour of what appears to be SD's 'smarter' version. 

However, does anyone know what will happen with audio alerts of bearingless traffic? Will SD have them too? PAW's version is quite effective, giving three increasingly 'threatening' categories of alert and - crucially, given that there is no horizontal distance and direction information - calling out vertical distance/separation if less than 1000 feet, above or below. So when you hear that another a/c is 200 feet above, that can be a useful prompt to descend, even if you're not sure exactly where that other aircraft is. 

On the new SD voice alerts, what - if anything - will you hear if bearingless gets close?  
By TimT - 3/31/2019 2:55:49 PM

neilmurg - 2/14/2019 6:08:34 PM

No way? Is that a conclusion after analysing the PAw algorithm?
For instance, how quickly could the strength of a signal from 200 miles away change, aircraft doing 140-250kn, vs a signal from 5 miles away @120kn?

Exactly. This is what the PAw documention says:

The absolute signal strength
transmitted is not a constant for all installations, so PilotAware can only work with relative
strengths. A voice alert is generated as the signal strength from an aircraft known by its
individual ICAO code, changes between strength bands.