Why so expensive (flight recorders)

This http://www.gpsinformation.net/main/altitude.htm guy (7 years ago) says
that accuracy was +-40 meters, but with DGPS should improve to +-10m (what
we should have now.).

This http://www.scottkurowski.com/flying.htm#accuracy made accurate
calculation on precisions, coming to +-7 feet precision in 2006 (?) with a
garmin 296.

These http://docs.controlvision.com/pages/gps_altimetry.php people say in
2004 that there is a bug in most of cheap gps chips that make altitude
calculation wrong by +-200 feet, and why it happens.

Most trekking gps have a baro sensor to compensate and calibrate gps
altitude nowadays (garmin for all S serie).





"toad" ha scritto nel messaggio
...
On Feb 21, 6:25 pm, Marc Ramsey wrote:
Ian wrote:
On Thu, 21 Feb 2008 18:42:11 +0000, Marc Ramsey wrote:

At the next IGC Plenary Meeting (29 February through 1 March), there
will be a specific proposal from the IGC Sporting Code Committee to
change SC3 to allow use of COTS GPS in conjunction with barographs for
Silver and Gold badges. May I, once again, suggest that you contact
your IGC delegate to make your viewpoint known?

Why bother with the barographs?

It's rather simple, GPS altitude is not currently an IGC recognized
means of measuring altitude in soaring performances, and changing that
is far more complex than adding COTS GPS as an alternate means of
documenting position evidence.

Marc

And what is so complicated in adding GPS altitiude as an IGC
recognized measurement ? Especially since GPS lat,lon is a
recognized. I am serious, please tell me.

Todd Smith
3S