Exemple #1
0
    #
    T = jd_to_jcent(jd)
    D, M, M1, F, omega = _constants(T)
    deltaEps = 0.0
    for tD, tM, tM1, tF, tomega, tpsiK, tpsiT, tepsK, tepsT in _tbl:
        arg = D*tD + M*tM + M1*tM1 + F*tF + omega*tomega
        deltaEps = deltaEps + (tepsK/10000.0 +
                               tepsT/100000.0 * T) * np.cos(arg)
    deltaEps = deltaEps / 3600
    deltaEps = d_to_r(deltaEps)
    return deltaEps

#
# Constant terms
#
_el0 = (d_to_r(dms_to_d(23, 26, 21.448)),
        d_to_r(dms_to_d(0, 0, -46.8150)),
        d_to_r(dms_to_d(0, 0, -0.00059)),
        d_to_r(dms_to_d(0, 0, 0.001813)))


def obliquity(jd):
    """Return the mean obliquity of the ecliptic.

    Low precision, but good enough for most uses. [Meeus-1998: equation 22.2].
    Accuracy is 1" over 2000 years and 10" over 4000 years.

    Arguments:
      - `jd` : Julian Day in dynamical time

    Returns:
Exemple #2
0
          - latitude in radians
          - radius in au

        """
        L = self.dimension(jd, planet, "L")
        B = self.dimension(jd, planet, "B")
        R = self.dimension(jd, planet, "R")
        return L, B, R


#
# Constant terms
#
_k0 = d_to_r(-1.397)
_k1 = d_to_r(-0.00031)
_k2 = d_to_r(dms_to_d(0, 0, -0.09033))
_k3 = d_to_r(dms_to_d(0, 0,  0.03916))


def vsop_to_fk5(jd, L, B):
    """Convert VSOP to FK5 coordinates.

    This is required only when using the full precision of the
    VSOP model.  [Meeus-1998: pg 219]

    Arguments:
      - `jd` : Julian Day in dynamical time
      - `L`  : longitude in radians
      - `B`  : latitude in radians

    Returns:
Exemple #3
0
 def test_geocentric_planet(self):
     ra, dec = geocentric_planet(2448976.5, "Venus", d_to_r(dms_to_d(0, 0, 16.749)), d_to_r(23.439669), days_per_second)
     np.testing.assert_array_almost_equal(r_to_d(ra), r_to_d(hms_to_fday(21, 4, 41.454) * pi2), decimal=5)
     np.testing.assert_almost_equal(r_to_d(dec), dms_to_d(-18, 53, 16.84), decimal=5)
Exemple #4
0
    #
    T = jd_to_jcent(jd)
    D, M, M1, F, omega = _constants(T)
    deltaEps = 0.0;
    for tD, tM, tM1, tF, tomega, tpsiK, tpsiT, tepsK, tepsT in _tbl:
        arg = D*tD + M*tM + M1*tM1 + F*tF + omega*tomega
        deltaEps = deltaEps + (tepsK/10000.0 + tepsT/100000.0 * T) * cos(arg)
    deltaEps = deltaEps / 3600
    deltaEps = d_to_r(deltaEps)
    return deltaEps


#
# Constant terms
# 
_el0 = (d_to_r(dms_to_d(23, 26,  21.448)), 
        d_to_r(dms_to_d( 0,  0, -46.8150)),
        d_to_r(dms_to_d( 0,  0,  -0.00059)),
        d_to_r(dms_to_d( 0,  0,   0.001813)))

def obliquity(jd):
    """Return the mean obliquity of the ecliptic. 
    
    Low precision, but good enough for most uses. [Meeus-1998: equation 22.2].
    
    Accuracy is 1" over 2000 years and 10" over 4000 years.

    Parameters:
        jd : Julian Day in dynamical time
        
    Returns:
Exemple #5
0
      - `L` : longitude in radians

    Returns:
      - corrected longitude in radians

    """
    jd = np.atleast_1d(jd)
    T = jd_to_jcent(jd)
    omega = _lk0 - _lk1 * T
    return _scalar_if_one(modpi2(L - _lk2 - _lk3 * np.sin(omega)))


#
# Constant terms
#
_lk4 = d_to_r(dms_to_d(0, 0, 20.4898))


def aberration_low(R):
    """Correct for aberration; low precision, but good enough for most uses.
    [Meeus-1998: pg 164]

    Arguments:
      - `R` : radius in au

    Returns:
      - correction in radians

    """
    return -_lk4 / R
Exemple #6
0
      - `L` : longitude in radians

    Returns:
      - corrected longitude in radians

    """
    jd = np.atleast_1d(jd)
    T = jd_to_jcent(jd)
    omega = _lk0 - _lk1 * T
    return _scalar_if_one(modpi2(L - _lk2 - _lk3 * np.sin(omega)))


#
# Constant terms
#
_lk4 = d_to_r(dms_to_d(0, 0, 20.4898))


def aberration_low(R):
    """Correct for aberration; low precision, but good enough for most uses.
    [Meeus-1998: pg 164]

    Arguments:
      - `R` : radius in au

    Returns:
      - correction in radians

    """
    return -_lk4 / R
Exemple #7
0
          - latitude in radians
          - radius in au

        """
        L = self.dimension(jd, planet, "L")
        B = self.dimension(jd, planet, "B")
        R = self.dimension(jd, planet, "R")
        return L, B, R


#
# Constant terms
#
_k0 = d_to_r(-1.397)
_k1 = d_to_r(-0.00031)
_k2 = d_to_r(dms_to_d(0, 0, -0.09033))
_k3 = d_to_r(dms_to_d(0, 0, 0.03916))


def vsop_to_fk5(jd, L, B):
    """Convert VSOP to FK5 coordinates.

    This is required only when using the full precision of the
    VSOP model.  [Meeus-1998: pg 219]

    Arguments:
      - `jd` : Julian Day in dynamical time
      - `L`  : longitude in radians
      - `B`  : latitude in radians

    Returns: