How to use the pyorbital.orbital.get_observer_look function in pyorbital

def get_angles(self, vis):
        """Get the sun and satellite angles from the current dataarray."""
        from pyorbital.astronomy import get_alt_az, sun_zenith_angle
        from pyorbital.orbital import get_observer_look

        lons, lats = vis.attrs['area'].get_lonlats(chunks=vis.data.chunks)
        sunalt, suna = get_alt_az(vis.attrs['start_time'], lons, lats)
        suna = np.rad2deg(suna)
        sunz = sun_zenith_angle(vis.attrs['start_time'], lons, lats)

        sat_lon, sat_lat, sat_alt = get_satpos(vis)
        sata, satel = get_observer_look(
            sat_lon,
            sat_lat,
            sat_alt / 1000.0,  # km
            vis.attrs['start_time'],
            lons, lats, 0)
        satz = 90 - satel
        return sata, satz, suna, sunz

def __call__(self, projectables, optional_datasets=None, **info):
        """Get the atmospherical correction. Uses pyspectral.
        """
        from pyspectral.atm_correction_ir import AtmosphericalCorrection

        band = projectables[0]

        if optional_datasets:
            satz = optional_datasets[0]
        else:
            from pyorbital.orbital import get_observer_look
            lons, lats = band.attrs['area'].get_lonlats_dask(CHUNK_SIZE)

            try:
                dummy, satel = get_observer_look(band.attrs['satellite_longitude'],
                                                 band.attrs[
                                                     'satellite_latitude'],
                                                 band.attrs[
                                                     'satellite_altitude'],
                                                 band.attrs['start_time'],
                                                 lons, lats, 0)
            except KeyError:
                raise KeyError(
                    'Band info is missing some meta data!')
            satz = 90 - satel
            del satel

        LOG.info('Correction for limb cooling')
        corrector = AtmosphericalCorrection(band.attrs['platform_name'],
                                            band.attrs['sensor'])

def get_angles(self, vis):
        """Get sun and satellite angles to use in crefl calculations."""
        from pyorbital.astronomy import get_alt_az, sun_zenith_angle
        from pyorbital.orbital import get_observer_look
        lons, lats = vis.attrs['area'].get_lonlats(chunks=vis.data.chunks)
        lons = da.where(lons >= 1e30, np.nan, lons)
        lats = da.where(lats >= 1e30, np.nan, lats)
        suna = get_alt_az(vis.attrs['start_time'], lons, lats)[1]
        suna = np.rad2deg(suna)
        sunz = sun_zenith_angle(vis.attrs['start_time'], lons, lats)
        sat_lon, sat_lat, sat_alt = get_satpos(vis)
        sata, satel = get_observer_look(
            sat_lon,
            sat_lat,
            sat_alt / 1000.0,  # km
            vis.attrs['start_time'],
            lons, lats, 0)
        satz = 90 - satel
        return sata, satz, suna, sunz