On Tue, 08 Jul 2008 20:50:48 -0700, noel.wade wrote:

I'm envisioning something like a Google Maps overlay that has color-
coded points or blobs based on the average vario reading or climb-rate
in a given area. Obviously you would need a certain number of
overlapping or nearby data-points to generate a decent average.

Don't forget that time of day (and of year?) is likely to be important.
The simplest approach might be to simply break each trace into separate
points, each interpolated between successive GPS fixes and indexed by
- location,
- date&time,
- altitude(?)

The value at the point would be the vertical rate calculated from time
interval and altitude difference, possibly adjusted as you suggest for
flying speed and glider polar.

When you have enough data it should be possible to see if there's any
usable signal amongst the noise.


--
martin@ | Martin Gregorie
gregorie. |
org | Zappa fan & glider pilot