Darryl,

INS would be like a GPS that had accurate heading info - would still
need TAS to solve the wind triangle, just like on an E6B.

I didn't think it all the way through, obviously!

The trouble with TE probes is that they are fragile have several
failure points. So it's nice to have a backup system (electronic TE
on a 302, for example).

My experience with a non WAAS Themi, which also drives my mSeeYou, is
that the "vario" data, once established in a thermal, is pretty good -
since I'm looking for differences around the circle, not absolute
climb values. And having the GPS show where in the thermal the
stronger lift was located is useful. But it is not a replacement for
a good TE vario.

I'm just curious if the increased accuracy of WAAS can be merged into
an instrument that will present a clearer 3-D picture of a thermal.
The best current vario only tells you how well you were climbing a few
seconds ago, but not where. PDA software is pretty good at showing
historical flight path, but I think there is room for improvement on
how to display a thermal in 3D that is useful for a pilot trying to
dig out of a hole or max out a boomer.

I'm going to have to run some simultaneous traces from a conventional
logger (pressure altitude) and my PDA logger (GPS altitude) and
compare the thermal data in SeeYou.

Fun to what-if...!

Kirk