Class IodLaplace


  • public class IodLaplace
    extends Object
    Laplace angles-only initial orbit determination, assuming Keplerian motion. An orbit is determined from three angular observations from the same site. Reference: Bate, R., Mueller, D. D., & White, J. E. (1971). Fundamentals of astrodynamics. New York: Dover Publications.
    Since:
    10.1
    Author:
    Shiva Iyer
    • Constructor Detail

      • IodLaplace

        public IodLaplace​(double mu)
        Constructor.
        Parameters:
        mu - gravitational constant
    • Method Detail

      • estimate

        public CartesianOrbit estimate​(Frame frame,
                                       PVCoordinates obsPva,
                                       AngularRaDec raDec1,
                                       AngularRaDec raDec2,
                                       AngularRaDec raDec3)
        Estimate the orbit from three angular observations at the same location.
        Parameters:
        frame - inertial frame for observer coordinates and orbit estimate
        obsPva - Observer coordinates at time of raDec2
        raDec1 - first angular observation
        raDec2 - second angular observation
        raDec3 - third angular observation
        Returns:
        estimate of the orbit at the central date obsDate2 or null if no estimate is possible with the given data
        Since:
        11.0
      • estimate

        public CartesianOrbit estimate​(Frame frame,
                                       PVCoordinates obsPva,
                                       AbsoluteDate obsDate1,
                                       Vector3D los1,
                                       AbsoluteDate obsDate2,
                                       Vector3D los2,
                                       AbsoluteDate obsDate3,
                                       Vector3D los3)
        Estimate orbit from three line of sight angles from the same location.
        Parameters:
        frame - inertial frame for observer coordinates and orbit estimate
        obsPva - Observer coordinates at time obsDate2
        obsDate1 - date of observation 1
        los1 - line of sight unit vector 1
        obsDate2 - date of observation 2
        los2 - line of sight unit vector 2
        obsDate3 - date of observation 3
        los3 - line of sight unit vector 3
        Returns:
        estimate of the orbit at the central date obsDate2 or null if no estimate is possible with the given data
      • lineOfSight

        public static Vector3D lineOfSight​(double alpha,
                                           double delta)
        Calculates the line of sight vector.
        Parameters:
        alpha - right ascension angle, in radians
        delta - declination angle, in radians
        Returns:
        the line of sight vector
        Since:
        11.0
      • lineOfSight

        public static Vector3D lineOfSight​(AngularRaDec raDec)
        Calculate the line of sight vector from an AngularRaDec measurement.
        Parameters:
        raDec - measurement
        Returns:
        the line of sight vector
        Since:
        11.0