[Xastir] Airplanes, anyone an expert?

[Curt Mills]

On Tue, Feb 23, 2016 at 12:01 PM, John Goerzen <jgoerzen at complete.org>
wrote:

> You probably don't want to auto-switch at all.
>

Actually I do! I wrote the script for my own interests, which in this case
are light aircraft (CAP) and helicopters flying over search areas. I'd like
the symbols to at least attempt to show which is which w/o having to have
an internet connection to an internet database to look them up. Often our
search areas are in the mountains and we have no such connection.

As far as the larger planes: I live/work near Paine Field (Everett Boeing
plant is right next to me here), so there are helo's, light aircraft, and
lots jets flying in and out of here all day long giving me plenty to test
with. Plus I have large aircraft flying to/from Seatac and Vancouver way up
high. Lots of activity on my screen, and it's nice to have some quick
visual clue as to which type each of them are. We also have a couple of
flight museums at this field with ancient aircraft flying in/out sometimes,
but none of those have ADS-B currently. Not sure if they'll be able to get
an exception for those after 2020?

Not trying for extreme accuracy on the switching of symbols, just a quick
rough indication. So far those speeds I listed seem to be working for the
majority, but haven't seen helo's to test with yet. Yes, I know helo's can
go much faster than that, but in a search area they probably won't be going
fast.

Also: ADS-B transmits ground speed and flight level, not MSL altitude, so
be prepared when the planes are taking off/landing at different altitudes
due to changing barometric pressure.

Curt, member of Snohomish County Volunteer Search and Rescue since '99.

-- 
Curt, WE7U
http://wetnet.net/~we7u
http://www.sarguydigital.com