Why so expensive (flight recorders)

On Feb 23, 6:28 am, Ian Strachan wrote:
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- Hide quoted text -


.... snip usefull explanation of accuracy ...

There is more, but the above summarises the reasons why IGC has, so
far, not added GPS altitude to the Sporting Code where accurate
measurements are required.

Ian Strachan
Lasham Gliding Centre, UK
Chairman IGC GNSS Flight Recorder Approval Committee (GFAC)

Ian, thanks for that explanation.

My desire, even after hearing your clear explanation, to be able to
use GPS altitude comes from a willingness to allow "inaccurate"
measurements. Or more specifically to question, what level of
accuracy is truly needed for a Silver height gain claim ?

I have to read the report you referenced and learn what kind of
errors, but I would propose that even if the expected accuracy was as
large as 100m-200m, I would be comfortable allowing the Silver badge
to be claimed in the GPS altitude gain was greater that 1000m +
"expected max error".

It's my willingness to accept reduced accuracy for reduced cost that
would have me allow GPS altitude.

Again, this high tolerance for error would be for the lower level of
badges, not records.


A question for the group, what level of error (for badges) are you
comfortable with ?

Thanks again
Todd Smith