"Curt, There has to be something seriously wrong there.

The kalman filter slips during constellation changes are only about 10 meters max (+/- 5m) providing you have reasonable sat geometry. For the sort of jumps you're seeing, it suggests that…"

"By the way Yves, I wasn't meaning to hijack your thread, since I think you've arrived at the best practical solution to height control, but rather to try to clear up some confusion about the source of the height "noise" from GPS's in particular."

"or is it SA error?

No Darren, SA has been off for a number of years now. (it was > +/- 50 metres in X and Y when it was on).

Height is the most sensitive parameter from the triangulation process, simply because of the geometry of the sats.
The low…"

"It's not so much that the GPS signal is noisy, but rather that the visible satellites keep changing particularly when the aircraft is banking and the antenna loses sight of lower elevation satellites.
These low elevation satellites bias the solution…"

"This is typical BBC scaremongering;

Firstly, even in the height of the solar storms, the GPS soldiered (albeitly with larger errors).
We are currently in a Solar Minimum that is slow in starting back to the peak that is normally an 11 yr cycle.
It…"

"The capacitor will only contribute a "hard" error by virtue of the leads that may have some small ferrous component.
Otherwise, there will be much more pervasive errors from nearby components that are likely to acquire permanent magnetic fields, not…"

"Looks interesting....Without giving too much away, how does the system do terrain following ?"