shackhartmann.py 文件源码

def psf_shift(lenslet_efl, dx, dy, mag=1):
    ''' Computes the shift of a PSF, in microns.

    Args:
        lenslet_efl (`microns`): EFL of lenslets.

        dx (`np.ndarray`): dx gradient of wavefront.

        dy (`np.ndarray`): dy gradient of wavefront.

        mag (`float`): magnification of the collimation system.

    Returns:
        `numpy.ndarray`: array of PSF shifts.

    Notes:
        see eq. 12 of Chanan, "Principles of Wavefront Sensing and Reconstruction"
        delta = m * fl * grad(z)
        m is magnification of SH system
        fl is lenslet focal length
        grad(z) is the x, y gradient of the opd, z, which is expressed in
        radians.

    '''
    coef = -mag * lenslet_efl
    return coef * dx, coef * dy