On Tuesday, December 29, 2015 at 10:35:32 PM UTC-8, Ramy wrote:
I second that claim. The only way you can observe someone climbing in Flarm is by observing the altitude difference through at least a minute or two.. The climb rate shown is indeed complete fantasy, and often showing 9.9 knots. I learned quickly the hard way to ignore the climb rate which Flarm shows and only look at altitude difference. Also the circling symbol is not a reliable indicator.
Sure Flam can be used tactically, and those of us not flying contest enjoy it immensely. But it is still far from providing accurate and reliable strategic information.

Ramy

Does anyone know if the rate of climb transmitted is barometric of GPS derived? In either case, it is highly inaccurate, by design. It is one second snapshots of either a jittery GPS altitude, or cockpit pressure, unfiltered and uncompensated. Try running your variometer on cockpit pressure sometime and see how accurate it is. When we get ADS-B, at least it'll be hooked to the static system. For proof, look at the B records in the IGC file. Between 2 second records, it is not uncommon to see 10 meter jitters up and down.. There's your 9.9 knot thermal right there. Head for it if you want, but it is a figment of the Flarm's imagination. This is why when I hear the claim that climb rates should be suppressed as strategic, I know that pilot hasn't actually tried to use it.