It seems I introduced a bug in the airports code some time ago, which
has gone rather unnoticed, or somehow I escaped the blame for it: in
the 'tower' view, where the tower position is explicitly given in
apt.dat (most of the larger airports), I was incorrectly treating the
tower elevation as ASL, when it's AGL.
The fix is one line, but my apt_loader.cxx has Yon's performance patch
applied, so I can't easily generate a useful patch.
If someone with commit access could verify that the tower heights are
indeed silly at, for example, EDDM, change apt_loader.cxx around line
266 to look like:
last_tower = SGGeod::fromDegFt(lon, lat, elev + last_apt_elev);
instead of
last_tower = SGGeod::fromDegFt(lon, lat, elev);
And verify that all is well, that would terrific. EDDM is a good test
case because the field elevation is 1400ASL - so the tower is a long
way below the terrain. At airports with tall towers or close to sea
level, (EHAM, EGLL, etc) it won't be so noticeable.
Airports without an explicit tower entry compute a position, and use
apt_elevation + a hardcoded value (50') for the elevation, so they're
fine regardless of this fix.
Thanks,
James
------------------------------------------------------------------------------
SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada.
The future of the web can't happen without you. Join us at MIX09 to help
pave the way to the Next Web now. Learn more and register at
http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/
_______________________________________________
Flightgear-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/flightgear-devel
