equations.py 文件源码

def variability_prob(ndvi, ndsi, whiteness):
    """Use the probability of the spectral variability
    to identify clouds over land.

    Equation 15 (Zhu and Woodcock, 2012)

    Parameters
    ----------
    ndvi: ndarray
    ndsi: ndarray
    whiteness: ndarray

    Output
    ------
    ndarray :
        probability of cloud over land based on variability
    """
    ndi_max = np.fmax(np.absolute(ndvi), np.absolute(ndsi))
    f_max =  1.0 - np.fmax(ndi_max, whiteness)
    return f_max


# Eq 16, land_cloud_prob
# lCloud_Prob = lTemperature_Prob x Variability_Prob