sun_position.py 文件源码

def ecliptic_longitude(hUTC, dayofyear, year):
    """ Ecliptic longitude

    Args:
        hUTC: fractional hour (UTC time)
        dayofyear (int):
        year (int):

    Returns:
        (float) the ecliptic longitude (degrees)

    Details:
        World Meteorological Organization (2006).Guide to meteorological
        instruments and methods of observation. Geneva, Switzerland.
    """

    jd = julian_date(hUTC, dayofyear, year)
    n = jd - 2451545
    # mean longitude (deg)
    L = numpy.mod(280.46 + 0.9856474 * n, 360)
    # mean anomaly (deg)
    g = numpy.mod(357.528 + 0.9856003 * n, 360)

    return L + 1.915 * numpy.sin(numpy.radians(g)) + 0.02 * numpy.sin(
        numpy.radians(2 * g))