def strip_telescope_header(header, simplify_wcs=True):
    """
    Strip non-JWST keywords that confuse `jwst.datamodels.util.open`.
    
    Parameters
    ----------
    header : `~astropy.io.fits.Header`
        Input FITS header.
    
    """
    import astropy.wcs as pywcs
    new_header = header.copy()
    if 'TELESCOP' in new_header:
        if new_header['TELESCOP'] != 'JWST':
            keys = ['TELESCOP', 'FILTER', 'DETECTOR', 'INSTRUME']
            for key in keys:
                if key in header:
                    new_header.remove(key)
    if simplify_wcs:
        orig_wcs = pywcs.WCS(new_header)
        new_header = orig_wcs.to_header()
        new_header['EXTNAME'] = 'SCI'
        new_header['RADESYS'] = 'ICRS'
        new_header['CDELT1'] = -new_header['PC1_1']
        new_header['CDELT2'] = new_header['PC2_2']
        new_header['PC1_1'] = -1
        new_header['PC2_2'] = 1
    return new_header
