On Fri, 2009-03-20 at 08:11 +1100, Greg Hawkes wrote: > Hello all, > > FlightGear's "Tower" view at my local airport (Melbourne's Tullamarine, > YMML) is about 300 metres from the actual location of the air traffic > control tower. I would like to change the Tower View's "From" location > to correspond to the actual location of the tower. > > I thought I could do this easily by editing the apt.dat.gz file in > FlightGear's ~/Airports/ directory. I gunzip-ed, edited, and gzip-ed the > file, and updated the "14" record for YMML as follows: > 14 -37.669465 144.830636 0 0 ATC Tower > > (These coordinates were obtained from Google Earth.) > > However, when I run FlightGear the view location of the "Tower" view is > unchanged. When I browse the internal properties, I find the following > values: > /sim/tower/airport-id='YMML' > /sim/tower/altitude-ft='483' > /sim/tower/latitude-deg='-37.66919517' > /sim/tower/longitude-deg='144.8451658' > > Obviously these values do not correspond with those I have inserted into > apt.dat.gz. Where does FlightGear obtain these values? > > The "altitude-ft" parameter is curious. According to this site > http://www.airservicesaustralia.com/aboutus/facilities/towers/melbournetower.asp > > ...the cabin is 120 feet (about 37 metres) above ground. Where does > FlightGear get its "483 feet" value? What is the datum for this number? > > Does FlightGear make use of the apt.dat.gz file to initialise its > airport data? If not, what is this file used for? > > Regards, > Greg Hawkes
According to http://www.melbourneairport.com.au/about_airport/facts_figures/technicial.asp the airport is 434 feet above sea level, which means flightgear is putting the cab about 50 feet above the ground, which is the default tower height. Tower locations are not parsed from apt.dat in version 1.0.0. You need version 1.9.0 for this to work (any build later than Thu Dec 18 06:52:51 2008 UTC.) Also note that the third number specified is tower height in feet agl, so your tower entry should be: 14 -37.669465 144.830636 120 0 ATC Tower Ron ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com _______________________________________________ Flightgear-users mailing list Flightgear-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-users
