On Wed, Apr 7, 2010 at 10:06 PM, Peter Brown <smoothwater...@adelphia.net> wrote:
> Perhaps this has been brought up before, but I see that the ILS "beam" data > for each airport on the mpmap is derived from the runway alignment (as > verified in taxidraw). This doesn't allow for magnetic deviation, and > therefore all the course headings are incorrect. Makes it tough to line up > with the ILS, unless you pull info from an outside source (airnav, > flightaware, etc) for each arrival airport. > Example at KBTV, runway 15 - > mpmap ILS course 130.92 degrees > Flightaware ILS approach plate, 146 degrees. I'm not familiar with mpmap, but that's not a problem for FlightGear itself - the localizer directions are all specified in Navaids/nav.dat.gz in degrees true, independently of any runways they might be associated with (not all localizers are attached to a runway, and even when they are, the direction might be 10 degrees off from the runway). Here's the example for BTV (where I've flown the localizer in real life as well as in FlightGear): 12 44.46520000 -073.14009400 342 11030 18 0.000 IVOE KBTV 33 DME-ILS But then, the vast majority of runways don't have localizers. Perhaps the map is just trying to show an extended runway centreline, and the person who designed the app mixed up magentic and true heading. The Airports/apt.dat.gz file does give runway headings in degrees true, not degrees magentic, so there's no need to mess around with magnetic deviation. All the best, David ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
