1 // Calculate ILS heading
7 #include <simgear/compiler.h>
15 #include <simgear/math/sg_geodesy.hxx>
22 int main( int argc, char **argv ) {
25 cout << "Wrong usage" << endl;
28 double loc_lat = atof( argv[1] );
29 double loc_lon = atof( argv[2] );
31 double rwy_lat = atof( argv[4] );
32 double rwy_lon = atof( argv[5] );
33 double rwy_hdg = atof( argv[6] );
34 double rwy_len = atof( argv[7] ) * SG_DEGREES_TO_RADIANS;
35 // double rwy_wid = atof( argv[8] );
39 if ( rwy_hdg > 360.0 ) {
44 // calculate runway threshold point
45 double thresh_lat = 0.0, thresh_lon = 0.0, return_az = 0.0;
46 geo_direct_wgs_84 ( 0.0, rwy_lat, rwy_lon, rwy_hdg,
47 rwy_len / 2.0, &thresh_lat, &thresh_lon, &return_az );
48 cout << "Threshold = " << thresh_lat << "," << thresh_lon << endl;
50 // calculate distance from threshold to localizer
51 double az1, az2, dist_m;
52 geo_inverse_wgs_84( 0.0, loc_lat, loc_lon, thresh_lat, thresh_lon,
53 &az1, &az2, &dist_m );
54 cout << "Distance = " << dist_m << endl;
56 // back project that distance along the runway center line
57 double nloc_lat = 0.0, nloc_lon = 0.0;
58 geo_direct_wgs_84 ( 0.0, thresh_lat, thresh_lon, rwy_hdg + 180.0,
59 dist_m, &nloc_lat, &nloc_lon, &return_az );
60 printf("New localizer = %.6f %.6f\n", nloc_lat, nloc_lon );