On Jan 10, 3:37*pm, "Paul Remde" wrote:
Hi,

The wind data calculated by the 302 is not saved in the flight log. *SeeYou
uses wind drift while circling to estimate the wind speed and direction
throughout the flight.

Paul Remde

"Hal" wrote in message

...
On Jan 10, 2:43 pm, Darryl Ramm wrote:



Hi Hal

The 302 does it's internal wind calculation using TAS vs. GPS
groundspeed to try to do better than just pure circling. Winpilot Pro
will also use TAS data output on the NMEA stream to also better
calculate wind in flight. I'm pretty sure it is doing this, not
directly reading the wind data that the 302 computes itself (and can
also put on its NMEA stream), since at times you'll see differences
between what a 303 display says and what WinPiltot Pro calculates.
SeeYou Mobile definitely does it's own wind calculations from the TAS
data and does not read the 302 calculated wind data. WinPilot Adv does
not use the TAS/GS enhanced calculation.

This wind calculation that SeeYou Mobile and (very likely) Winpilot
Pro ignore is calculated in the Cambridge 302, some people seem to
think the 303 is needed for this. The 303 is just a display. Obviously
you need it to see the 302 calculated wind, but the 302 can also send
this calculation on the NMEA stream without a 303 being attached. Just
most PDA software appears to ignore it. As I would if I was writing
the PDA software -- I'd want to be fully in control of my own wind
algorithm.

When not thermalling I find I only needs some smooth flight with turns
+/- 30 or so either side of track for few minutes to get reasonable
wind updates from the 302/303 or SeeYou Mobile and I'd be surprised if
Winpilot Pro is much different.

The 302/303 and WinPilot Pro show very good instantaneously calculated
headwind which is handy you can just point into wind and see the
maximum headwind component while in wave and this will be very
accurate.

Lets me expand on what Paul is saying about SeeYou (desktop not
Mobile) and wind. SeeYou (desktop) *can* use enhanced TAS data to
calculate wind from an IGC file - but obviously the file needs to
contain the TAS data. If you are downloading an IGC file from your
Cambridge 302 it won't have this, even though the Cambridge can put
this out on the NMEA steam. However the IGC logger built into Winpilot
Pro and SeeYou Mobile and maybe other PDA software will record (a sub-
sample of) the enhanced TAS data from the Cambridge 302 NMEA steam in
the B-records. Look at the header of any IGC file if you see the
string "TAS" in the I record (which describes the B-record format)
then it's recording TAS (or at least leaving space to do so).

In my 26E I have a Cambridge 302/303 and a PDA running SeeYou Mobile.
I'll mostly use SeeYou Mobile for Wind but will check against the 303
display. I'll download an IGC flight log from the 302 and use that for
OLC and similar since motorgliders require need the ENL (engine noise)
support for OLC. I also have SeeYou Mobile logging at 1 sample/sec for
nice smooth traces and will use that in SeeYou for flight analysis -
and it has the added benefit since it has TAS data embedded. (Since
I'm trying to see if my C302 security fail issues have been fixed I
also have that logging it at 1 sample /sec.).

You might want to look at having Winpilot Pro record a back-up flight
log and use that for analysis like looking at this wave flight.

If you can't do this you can always take a few circles at times just
to mark wind for non-TAS enhanced SeeYou analysis, not always
practical in a wave situations but it usually only takes a few
circles.

(You need to work that Diamond altitude wave flight out of Petaluma.
Do it man!).

Darryl