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flightgear/src/Airports/calc_loc.cxx
2009-08-23 21:43:09 +02:00

63 lines
1.7 KiB
C++

// Calculate ILS heading
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <simgear/compiler.h>
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <string>
#include <simgear/math/sg_geodesy.hxx>
using std::string;
using std::cout;
using std::endl;
int main( int argc, char **argv ) {
if ( argc != 9 ) {
cout << "Wrong usage" << endl;
}
double loc_lat = atof( argv[1] );
double loc_lon = atof( argv[2] );
string dir = argv[3];
double rwy_lat = atof( argv[4] );
double rwy_lon = atof( argv[5] );
double rwy_hdg = atof( argv[6] );
double rwy_len = atof( argv[7] ) * SG_DEGREES_TO_RADIANS;
// double rwy_wid = atof( argv[8] );
if ( dir == "FOR" ) {
rwy_hdg += 180.0;
if ( rwy_hdg > 360.0 ) {
rwy_hdg -= 360.0;
}
}
// calculate runway threshold point
double thresh_lat = 0.0, thresh_lon = 0.0, return_az = 0.0;
geo_direct_wgs_84 ( 0.0, rwy_lat, rwy_lon, rwy_hdg,
rwy_len / 2.0, &thresh_lat, &thresh_lon, &return_az );
cout << "Threshold = " << thresh_lat << "," << thresh_lon << endl;
// calculate distance from threshold to localizer
double az1, az2, dist_m;
geo_inverse_wgs_84( 0.0, loc_lat, loc_lon, thresh_lat, thresh_lon,
&az1, &az2, &dist_m );
cout << "Distance = " << dist_m << endl;
// back project that distance along the runway center line
double nloc_lat = 0.0, nloc_lon = 0.0;
geo_direct_wgs_84 ( 0.0, thresh_lat, thresh_lon, rwy_hdg + 180.0,
dist_m, &nloc_lat, &nloc_lon, &return_az );
printf("New localizer = %.6f %.6f\n", nloc_lat, nloc_lon );
return 0;
}