Now I understand what you meant with prediction, not referring to the
position!
yes I agree on this definition, from this point of view.
I look at it exactly as you do.

"Andy Blackburn" wrote in message
...

I'll buy the beer.

Prediction, projection, position, protection. I'm not very clear on the
finer points of my mother language apparently. ;-)

Here's how I look at it. FLARM calculates a projected flight path with a
probabilistic "error radius" determined based on flight parameters to
estimate a likely future position (assuming no change in control inputs) and
then maps these paths to estimate likely conflicts and warns if it finds
one. I consider that warning a prediction - if nothing changes the two
aircraft will likely collide. Sure, it's an estimate but I still consider
that more of a prediction than just putting airplane-shaped dots on a
display and telling the pilot "you figure it out". I'd rather have a
microprocessor and an algorithm than burying my head in a traffic display.
I'd call that warning a prediction but maybe I'm being sloppy with the
definitions.

The point is - FLARM will give you a warning only for pretty real threats. A
traffic advisory system can only annoy you with constant warnings of
aircraft in the vicinity whether they are a threat or not or leave it to you
to find threats.by staring at a display. You need to project a flight path
with some precision to strike a balance between too may false positives and
leaving too many possible threats suppressed until too late. Given how we
fly I think FLARM does quite well. It's also why ADS-B will struggle to
operate as a collision warning system for gliders - even if someone tries to
plaster a collision projection algorithm on top of some Garmin ADS-B unit.
PowerFLARM throws out the ADS-B information if it detects a target with both
FLARM and ADS-B Out.

9B