def add_nrcs_VV_from_HH(self, filename):
        if not 'Amplitude_HH' in self.ds.variables.keys():
            return
        layer_time_id, layer_date = Opendap.get_layer_datetime(None,
                self.convert_dstime_datetimes(self.get_dataset_time()))
        dims = list(self.ds.variables['dn_HH'].dimensions)
        dims[dims.index(self.timeVarName)] = layer_time_id
        src = [
                self.get_metaitem(filename, 'Amplitude_HH', dims)['src'],
                self.get_metaitem(filename, 'sigmaNought_HH', dims)['src'],
                {'SourceFilename': self.band_vrts['inciVRT'].filename, 'SourceBand': 1}
            ]
        dst = {
                'wkv': 'surface_backwards_scattering_coefficient_of_radar_wave',
                'PixelFunctionType': 'Sentinel1Sigma0HHToSigma0VV',
                'polarization': 'VV',
                'suffix': 'VV'}
        self.create_band(src, dst)
        self.dataset.FlushCache()