Ejemplo n.º 1
0
def test_orbit_accepts_ecliptic_plane():
    r = [1e09, -4e09, -1e09] * u.km
    v = [5e00, -1e01, -4e00] * u.km / u.s

    ss = Orbit.from_vectors(Sun, r, v, plane=Planes.EARTH_ECLIPTIC)

    assert ss.get_frame().is_equivalent_frame(HeliocentricEclipticJ2000(obstime=J2000))
Ejemplo n.º 2
0
def orbit_from_record(record):
    """Return :py:class:`~poliastro.twobody.orbit.Orbit` given a record.

        Retrieve info from JPL DASTCOM5 database.

        Parameters
        ----------
        record : int
            Object record.

        Returns
        -------
        orbit : ~poliastro.twobody.orbit.Orbit
            NEO orbit.

        """
    body_data = read_record(record)
    a = body_data["A"].item() * u.au
    ecc = body_data["EC"].item() * u.one
    inc = body_data["IN"].item() * u.deg
    raan = body_data["OM"].item() * u.deg
    argp = body_data["W"].item() * u.deg
    m = body_data["MA"].item() * u.deg
    nu = M_to_nu(m, ecc)
    epoch = Time(body_data["EPOCH"].item(), format="jd", scale="tdb")

    orbit = Orbit.from_classical(Sun, a, ecc, inc, raan, argp, nu, epoch)
    orbit._frame = HeliocentricEclipticJ2000(obstime=epoch)
    return orbit
Ejemplo n.º 3
0
def orbit_from_record(record):
    """Return :py:class:`~poliastro.twobody.orbit.Orbit` given a record.

    Retrieve info from JPL DASTCOM5 database.

    Parameters
    ----------
    record : int
        Object record.

    Returns
    -------
    orbit : ~poliastro.twobody.orbit.Orbit
        NEO orbit.

    """
    body_data = read_record(record)
    a = body_data["A"].item() * u.au
    ecc = body_data["EC"].item() * u.one
    inc = body_data["IN"].item() * u.deg
    raan = body_data["OM"].item() * u.deg
    argp = body_data["W"].item() * u.deg
    M = body_data["MA"].item() * u.deg
    epoch = Time(body_data["EPOCH"].item(), format="jd", scale="tdb")

    # NOTE: It is unclear how this conversion should happen,
    # see https://ssd-api.jpl.nasa.gov/doc/sbdb.html
    if ecc < 1:
        M = (M + np.pi * u.rad) % (2 * np.pi * u.rad) - np.pi * u.rad
        nu = E_to_nu(M_to_E(M, ecc), ecc)
    elif ecc == 1:
        nu = D_to_nu(M_to_D(M))
    else:
        nu = F_to_nu(M_to_F(M, ecc), ecc)

    orbit = Orbit.from_classical(Sun, a, ecc, inc, raan, argp, nu, epoch)
    orbit._frame = HeliocentricEclipticJ2000(obstime=epoch)
    return orbit