SeeYou Wind Calculation

[Ken Kochanski (KK)]

Good Morning,

How does SeeYou calc wind speed and direction when you are reviewewing
flight logs.

I notice the wind shifts direction and velocity ... even while running
ridges ... so I assume it is not using some measurement of drift while
thermal-ing ...

KK

[Darryl Ramm]

On Jun 2, 5:09*am, "Ken Kochanski (KK)" >
wrote:
> Good Morning,
>
> How does SeeYou calc wind speed and direction when you are reviewewing
> flight logs.
>
> I notice the wind shifts direction and velocity ... even while running
> ridges ... so I assume it is not using some measurement of drift while
> thermal-ing ...
>
> KK

It depends on the IGC file, there may be TAS data in the file or wind
vectors in the K-record in the IGC file. This has been discussed here
in the past. For a plain IGC file SeeYou can only use circle drift.


Darryl

[Ray[_5_]]

Darryl Ramm wrote:
> On Jun 2, 5:09 am, "Ken Kochanski (KK)" >
> wrote:
>> Good Morning,
>>
>> How does SeeYou calc wind speed and direction when you are reviewewing
>> flight logs.
>>
>> I notice the wind shifts direction and velocity ... even while running
>> ridges ... so I assume it is not using some measurement of drift while
>> thermal-ing ...
>>
>> KK
>
> It depends on the IGC file, there may be TAS data in the file or wind
> vectors in the K-record in the IGC file. This has been discussed here
> in the past. For a plain IGC file SeeYou can only use circle drift.
>
>
> Darryl
From the SYM manual:
Wind is calculated using three methods in SeeYou Mobile
.. Position drift when Lat/Lon are the only available data
.. Groundspeed difference when groundspeed and track are received from
the GPS
.. Combination of Groundspeed and straight flight when true air speed is
received from the instrument.
In this case, the wind is updated in straight flight as well.

[Darryl Ramm]

On Jun 2, 7:39*pm, Ray > wrote:
> Darryl Ramm wrote:
> > On Jun 2, 5:09 am, "Ken Kochanski (KK)" >
> > wrote:
> >> Good Morning,
>
> >> How does SeeYou calc wind speed and direction when you are reviewewing
> >> flight logs.
>
> >> I notice the wind shifts direction and velocity ... even while running
> >> ridges ... so I assume it is not using some measurement of drift while
> >> thermal-ing ...
>
> >> KK
>
> > It depends on the IGC file, there may be TAS data in the file or wind
> > vectors in the K-record in the IGC file. This has been discussed here
> > in the past. For a plain IGC file SeeYou can only use circle drift.
>
> > Darryl
>
> *From the SYM manual:
> Wind is calculated using three methods in SeeYou Mobile
> . Position drift when Lat/Lon are the only available data
> . Groundspeed difference when groundspeed and track are received from
> the GPS
> . Combination of Groundspeed and straight flight when true air speed is
> received from the instrument.
> In this case, the wind is updated in straight flight as well.

You are quoting the SeeYou Mobile documentation, the question was for
SeeYou. It is not what was received from the GPS but what is in the
IGC file. And don't assume because some logger has or gets certain
data it is going to write it to the file. e.g. The C302 will often
output very nice TAS data on NMEA but does not log it to it's own IGC
file (but SeeYou Mobile will log the TAS data to it's IGC flight log
file if it is being driven from that C302). Also just be cautions
looking at the wind vector, it can appear to jump around but have very
low values even when driven by not really meaningful data.

I may be wrong on what I said on the K-record with wind direction/
speed data. SeeYou does just seem to be ignoring that. Seems a bit
stange to do that if SeeYou Mobile bothers to write them in the first
place to an IGC file.


Darryl