inline double get_user_speed() const {return user_speed; }
inline double get_wind_from_east() const {return wind_from_east; }
inline double get_wind_from_north() const {return wind_from_north; }
inline double get_user_speed() const {return user_speed; }
inline double get_wind_from_east() const {return wind_from_east; }
inline double get_wind_from_north() const {return wind_from_north; }