Mode C and S detection - SkyDemon oddity...or not

[Admin]

Hi Peter, Robert,

The basestation can be configured as
RX, or
TX/RX

I agree about not having false warnings generated,
so when the RF data is sent, it is tagged saying what the sending type is, ie type=basestation,
therfore it is very easy in S/W (at the receiver) to code up ignoring/icon-type/non-display of type=basestation

I am trying to do some forward thinking, and hoping to get the NAV tools to have different icons for the traffic/obstacle types,
at the moment in the display, you can have any icon type you want (so long as it's an aircraft  )
but of course, in the future we will probably want :-
- Control Tower (basestation)
- Dynamic Obstruction (e.g. Crane)
- Dynamic Zoning (e.g. NOTAM)
- Static Obstruction (e.g. Windfarm, although these can generally be coded directly to the NavTool Database)
- Helicoptor
- Balloon
- Glider
- Drone (Dare I say!)

etc ...

Thx
Lee

[RobertPBham]

That sounds great with the obstacles icon types. Definitely helpful long term! I've had a couple of Mode S reports in the circuit and ignored them as they were reported ground level - the worst thing to happen with erroneous reports is that you start to automatically ignore them which is a danger!

Do we know how Wellesbourne is viewing the traffic - I can always go up to the tower and see but was interested in what they are expecting to see and how they are handling the information?

[Keithvinning]

At Wellesbourne Jon in the tower is very tech savvy as you will know from the weather website. Initially he is going to use his own personal copy of Sky demon. But I think that he will also investigate XC Soar, free and less cluttered as you say. Although I must add that sky demon can be very effectively de cluttered and works well.

Other brilliant navigation packages are also available 


Keith

[Richard W]

Not directly a PAW issue, I know, but I wired the audio from SD into the headset system for the first time.  On final there were so many warnings about imminent collision with the traffic at the hold and on the apron that I had to physically pull the plug.  Very distracting.

[Keithvinning]

Hi Richard
I guess that it's PilotAware doing its job. However it is distracting. We need to think about how to overcome this operationally in a better way than pulling the plug

Keith

[Admin]

Just to confirm, this is SkyDemon audio NOT Pilotaware?
Have you reported to Tim at SkyDemon ?

[Richard W]

Yes, SkyDemon audio. I have not reported it to Tim, I assume it is the nature of the beast. Is it supposed to suppress warnings from A/C on the ground, or some such?  After all, I was heading very close to someone at the hold.

[Admin]

Hi Richard
I'm not sure of the algorithm used by Tim but you can be sure you are one of a small group who have exercised it, so please give Tim some feedback/reporting to help him refine his product
It would also be worth mentioning that we have track files to replay the events to help him reproduce your findings

Thx
Lee

[Richard W]

Hi Lee,
The trouble is, I can't make a very objective report.  I heard a racket, and pulled the plug without even looking at the display.  Good point about the files though, I will take a closer look.
Richard

[RobertPBham]

Hi all,

On Friday I had a trip to Newquay (arriving back yesterday).

This gave me a good chance to test with the new version of SkyDemon.

On the journey down we had one Mode C/S alert - this was for a helicopter 200 feet below us. The height was reported correctly (by eye) but the helicopter was rather close before it flagged up as an alert - approximately 500 to 1000 metres. We both knew of each other's presence as we were under controller (listening squawk) but I did think it was a bit close for comfort if you were unaware of the traffic!

This could be due to the positioning of my PAW but what is expected detection range and alerting range (horizontally)?

I had one alert close to Newquay of a plane at 0.0 but I believe this was our own plane being detected as none of us saw any other traffic. The weather was fairly rubbish on Friday so not much was about!

Thanks
Rob

[exfirepro]

Hi Robert,

Bearingless Alerts are not based on distance but on received signal strength. The distance at which you receive alerts therefore depends on the power output and efficiency of the transponder system, the efficiency of your own setup and the 'Detection Range' you have selected in your PAW.

You should have received a series of 3 alerts - 'Traffic Notice', then 'Traffic Alert' and finally 'Traffic Danger' as the helicopter approached. Are you saying you didn't get these? We took a lot of care designing the trigger levels to cope with 'GA' strength transponders at 'safe' alert distances, so if not I would suspect screening of your ADSB antenna from the helicopter's transponder. Please let me know if this is likely.

Regards

Peter

Peter

[RobertPBham]

Hi Peter,

Thanks for the information.

As a rough guide the helicopter was at our 11 o'clock as we approached it. We then passed it as 9 o'clock (200m away and 200ft below) - we were heading south and it was travelling west - so approaching each other and going in different directions. I don't have the audio alerts as my PAW isn't connected to the internal comms system - I rely solely on the SkyDemon alert rings - I only received one SkyDemon alert and this was a yellow ring as I remember with the -0.2 - seem to roughly remember it did change to green once he had passed behind.

My PAW is set to 4000ft - I assumed this was height based but if horizontal as well, then it was a lot closer than 4000ft. Definitely a possibility shielding was an issue - PAW located in rear, passenger in front of that and then us pilots and engine!

Would you say it's a requirement to have the audio connected or should the SkyDemon rings be enough - I've never seen a SkyDemon ring alert at 4000ft - the most I've seen is 1000ft and that was on the trip to Jersey.

Thanks
Rob

[exfirepro]

My PAW is set to 4000ft - I assumed this was height based but if horizontal as well, then it was a lot closer than 4000ft. Definitely a possibility shielding was an issue - PAW located in rear, passenger in front of that and then us pilots and engine!

Hi Rob,

These settings are for the Maximum Vertical Separation that will appear as warnings. Horizontal alerts for bearingless targets (the rings) are determined by the Range Setting in PAW, which as I said earlier is not based directly on distance. I normally fly on the 'Medium' setting, which generally gives me plenty of warning.

Would you say it's a requirement to have the audio connected or should the SkyDemon rings be enough - I've never seen a SkyDemon ring alert at 4000ft - the most I've seen is 1000ft and that was on the trip to Jersey.

In general PAW's audio warnings will alert you slightly quicker than the rings, so worth connecting it. They also mean you don't need to watch the screen so much, so are more likely to pick up aircraft visually - remember many won't appear on screen at all if they are not transponder, ADSB, or P3i equipped.

Regards

Peter

[Paul_Sengupta]

Yes, the 4000ft is height.

Having the antenna down the back is possibly the worst place for it as you really want the longest range of detection being the direction you're travelling in. I have my PAW stuck up on my dashboard with a clear view ahead and to the sides, though shielded ahead and down by the engine and airframe. However, it might work ok if you increase the detection range (using lower signal strengths to alert) as transponders are reasonably high power. Might not work so well for P3i though.

[RobertPBham]

Hi Paul,

I'll give that a try next time I'm there. One of the main issues I have is cable length for the ADSB antennae - with both front seats occupied and passengers, trying to get somewhere to locate the PAW is difficult (hence it being in the luggage compartment at the back) - especially as they are club aircraft and I cannot permanently install the PAW.

Thanks
Rob