// cout << nav_gslon << "," << nav_gslat << " "
// << tlon << "," << tlat << " (" << nav_elev << ")"
// << endl;
Point3D p1 = sgGeodToCart( Point3D(tlon*SGD_DEGREES_TO_RADIANS,
tlat*SGD_DEGREES_TO_RADIANS,
// cout << nav_gslon << "," << nav_gslat << " "
// << tlon << "," << tlat << " (" << nav_elev << ")"
// << endl;
Point3D p1 = sgGeodToCart( Point3D(tlon*SGD_DEGREES_TO_RADIANS,
tlat*SGD_DEGREES_TO_RADIANS,