def data_class(self):
        """
        creates a Data() instance of lenstronomy based on knowledge of the observation

        :return: instance of Data() class
        """
        x_grid, y_grid, ra_at_xy_0, dec_at_xy_0, x_at_radec_0, y_at_radec_0, Mpix2coord, Mcoord2pix = util.make_grid_with_coordtransform(
            numPix=self.numpix, deltapix=self.pixel_scale, subgrid_res=1, left_lower=False, inverse=False)
        kwargs_data = {'numPix': self.numpix, 'ra_at_xy_0': ra_at_xy_0, 'dec_at_xy_0': dec_at_xy_0,
                       'transform_pix2angle': Mpix2coord,
                       'background_rms': self.background_noise,
                       'exp_time': self.scaled_exposure_time}
        data_class = Data(kwargs_data)
        return data_class
creates a Data() instance of lenstronomy based on knowledge of the observation

        :return: instance of Data() class