Hi,

What is the advantage of a glide footprint to your soaring?

The programs I've seen determine reachable landing sites along a straight
line only. XCSoar can also show where that direct path would intersect
terrain (computed using a safety margin, so it is not really the point
of impact, but I like to think of it that way).

But it does so only for the current "goto" path, that is along the task set
or to a selected landing site.

The glide footprint simultaneously provides the same information for all
sites on the map.

Ideally it can also tell you wether you can reach a field by "flying
around a mountain" and escape routes when flying in mountains (Although
when I ever get that far in my training I hope to have them ready long
before I get to need them).

I have not checked the programs I tried for this. I suspect they just shoot
a few radials out from the current position and connect the intersections
with terrain they find that way for a closed footprint. A real pathfinding
algorithm sounds too computationally expensive to me.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn
http://www.marian-aldenhoevel.de
"Success is the happy feeling you get between the time you
do something and the time you tell a woman what you did."