Questions/Comments about OGN

I fly in the UK and in the Alps. We have good OGN coverage in both
places, and in both places all (Alps) or most (UK) cross country
gliders carry Flarm. I manage 20 receivers.

A primary benefit of OGN tracking is to make gliding more of a
spectator sport - so if you're not flying, you can see what other
people are doing or have done today. It gets used for most
competitions, with websites configured to show just the gliders in the
competition, with their relative position in the race. Much more
interesting for the spectators than just waiting for finishers. As an
additional benefit we get useful traffic data for conversations with the
regulators about airspace.

My club, and many others, also use it for logging gliders and tugs up
and down, improving the accuracy of otherwise hand-recorded logs.

As an instructor, it's very useful being able to look on the club
website and see where all the gliders that launched from the club are
at the end of the day - whether home, local or still remote. Even
down to which field they landed out in.

In the Alps it has proved very useful for S&R in the event that a crash
has occurred. Also in the Alps, there are a number of mountaintop
receivers with solar power supplies (not within the $250 budget
mentioned later though).

In the UK there's a parallel system to Flarm, called PilotAware, which
is like Flarm for GA aircraft. An extension of the OGN system
rebroadcasts Flarm signals to PilotAware equipped aircraft. That
system is being extended to include multi-laterated transponder
signals.

The backend of the system is opensource and integrates targets from
a number of systems including OGN (Flarm), PilotAware and others.
So all that traffic data is available. There are several websites that
make use of that data, presented in different ways.

Typical cost of a receiver is in the order of $250. Range can be high -
100km or more - it's pretty much line of sight - but you get much
better results with receivers on a grid around 30km depending on
terrain - then you get multiple receivers picking up an aircraft.
Ground stations are best with decent antennas mounted high and
clear of buildings.

All in all, it's been an extremely successful example of building on
some existing technologies (ie Flarm) to provide a lot of additional
functionality.

Paul