wrote:
I recently reread Richard Johnson's article, "Sailplane Performance
Flight Test Methods" in the May, 1989 issue of Soaring magazine. In
the article Johnson mentions the Deceleration Measurement method of
determining a performance polar. It had occured to me a couple of
years ago that such a method could be used in conjunction with GPS data
as a fairly simple way of measuring glider performance. I envision
importing the GPS time, altitude, and position data into a spread sheet
application to do the number crunching. Anyone out there ever tried
anything like that? Anyone have suggestions or caveats about doing it?

Myles Bradley

Reply:
The other columns on the spread sheet will be for airmass movement.
Figure out how to deal with this and it will be as easy as it looks.
This is why Idafleig uses a "master" glider in formation and compares
performance.
UH