On 20 Mar 2010, at 23:36, Curtis Olson wrote: > The nav radio does not work in magnetic headings. It works in which ever > alignment the station was setup in. In the 60's when GEP was installed, it > was aligned with magnetic north at that time. In the subsequent years, the > actual magnetic north has shifted several degrees, but the FAA does not go in > and adjust the orientation of the station radials every few months. This > would cause all kinds of cascading changes with radials, victor highways, > intersection points, etc. Instead, they just leave it where it is. So it's > key to align the vor station with the defined offset, not the current > magnetic offset ...
Sorry, yes, I was aware of this, it's the 'twist' parameter, which comes from the dreaded 'multiuse' column in the nav.dat data. navradio.cxx *does* reference /environment/magnetic-variation-deg, but only as part of the nav-slaved-to-gps option which I will be attacking soon. Form looking at the navradio code, I do *think* the alignment/twist logic is ok: nav[n]/heading-deg is the true heading to the station, computed by wgs84_inverse, and nav[n]/radials/actual-deg is computed as the true heading minus the twist as specified in degrees in nav.data. As ever, I am not a pilot, so I am happy to be corrected, but the above description does fit with my understanding of the real-world situation, and Curt's description above. James ------------------------------------------------------------------------------ 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
