Thanks for your reply, next time it occurs I'll take screenshots/record a video of the screen.
Essentially, without no prior warning, I instantly see an amber or red circle around my airplane on Skydemon, and an aural warning about the colliding traffic, often same altitude or slightly above/below.
Due to airspace limitations, were always flying at 1500aal (2000amls), and I often wonder if I'm picking up signals from aircraft on the ground.
But nevertheless, once the waning is out, I cannot see any trace of the other aircraft. Anyway, I'll try and provide more details, also about the configuration once I'm flying.
Hi ILIMB,
As Lee has said, a coloured circle appearing around your aircraft on SkyDemon is advising you of the presence of what we call a 'Bearingless Target'. This is
not a 'ghost', but an aircraft which is simply not transmitting its geographical position. Bearingless alerts are triggered by reception of a signal
direct from another aircraft's Mode-C transponder (which
can't transmit a geographical position) or Mode-S transponder, which by default doesn't transmit a geographical position unless it has a GPS position deliberately supplied to 'convert' the transponder signal to 'ADS-B Out'. In either of the above cases, SkyDemon (or any other traffic system for that matter) cannot report the aircraft's geographical position unless this has been determined through 'Multilateration' (determination of the aircraft's position by triangulating the received transponder signal using a number of fixed ground receiving stations). Where this can be achieved, the aircraft will appear on your tablet as a moving aircraft, rather than a coloured circle. We refer to this function as 'Mode-S/3D'.
In both Bearingless cases above, the circle will be accompanied by a figure to denote the Relative Altitude of the other aircraft (with respect to your own), so you can see whether it is above, below or at a similar level, and the colour of the circle will indicate the relative degree of risk which the aircraft is deemed to present*. In the case of a signal from a Mode-S transponder, the circle will also be annotated with the aircraft's Registration or Flight ID (depending on the setting selected for Bearingless Traffic in your PilotAware Configuration Screen).
* The one variable which affects the colour rings is the transmission power of the transponder. In the case of high power transponders - used in commercial aircraft (including when taxying on the ground), this can cause a yellow/amber or red 'danger' warning, when the actual risk is still relatively low. This is almost certainly what you have been experiencing. If so, you should be able to check the relative altitude annotated to the circle and disregard the alert if the aircraft is obviously on the ground or clearly beyond visible range.
If you are still unsure, please refer to the PilotAware Users Guides available in the 'Support' Section on
https://www.pilotaware.com Hope this helps.
Best Regards
Peter
