from __future__ import absolute_import, division, print_function import os.path from astropy.io import fits from stsci.tools import fileutil from . import utils from . import wfpc2_dgeo import logging logger = logging.getLogger("stwcs.updatewcs.apply_corrections") # Note: The order of corrections is important # A dictionary which lists the allowed corrections for each instrument. # These are the default corrections applied also in the pipeline. allowed_corrections = {'WFPC2': ['DET2IMCorr', 'MakeWCS', 'CompSIP', 'VACorr'], 'ACS': ['DET2IMCorr', 'TDDCorr', 'MakeWCS', 'CompSIP', 'VACorr', 'NPOLCorr'], 'STIS': ['MakeWCS', 'CompSIP', 'VACorr'], 'NICMOS': ['MakeWCS', 'CompSIP', 'VACorr'], 'WFC3': ['DET2IMCorr', 'MakeWCS', 'CompSIP', 'VACorr', 'NPOLCorr'], } cnames = {'DET2IMCorr': 'Detector to Image Correction', 'TDDCorr': 'Time Dependent Distortion Correction', 'MakeWCS': 'Recalculate basic WCS keywords based on the distortion model', 'CompSIP': 'Given IDCTAB distortion model calculate the SIP coefficients', 'VACorr': 'Velocity Aberration Correction', 'NPOLCorr': 'Lookup Table Distortion' } def setCorrections(fname, vacorr=True, tddcorr=True, npolcorr=True, d2imcorr=True): """ Creates a list of corrections to be applied to a file based on user input paramters and allowed corrections for the instrument. """ instrument = fits.getval(fname, 'INSTRUME') # make a copy of this list acorr = allowed_corrections[instrument][:] # For WFPC2 images, the old-style DGEOFILE needs to be # converted on-the-fly into a proper D2IMFILE here... if instrument == 'WFPC2': # check for DGEOFILE, and convert it to D2IMFILE if found d2imfile = wfpc2_dgeo.update_wfpc2_d2geofile(fname) # Check if idctab is present on disk # If kw IDCTAB is present in the header but the file is # not found on disk, do not run TDDCorr, MakeCWS and CompSIP if not foundIDCTAB(fname): if 'TDDCorr' in acorr: acorr.remove('TDDCorr') if 'MakeWCS' in acorr: acorr.remove('MakeWCS') if 'CompSIP' in acorr: acorr.remove('CompSIP') if 'VACorr' in acorr and not vacorr: acorr.remove('VACorr') if 'TDDCorr' in acorr: tddcorr = applyTDDCorr(fname, tddcorr) if not tddcorr: acorr.remove('TDDCorr') if 'NPOLCorr' in acorr: npolcorr = applyNpolCorr(fname, npolcorr) if not npolcorr: acorr.remove('NPOLCorr') if 'DET2IMCorr' in acorr: d2imcorr = apply_d2im_correction(fname, d2imcorr) if not d2imcorr: acorr.remove('DET2IMCorr') logger.info("Corrections to be applied to {0} {1}".format(fname, acorr)) return acorr def foundIDCTAB(fname): """ This functions looks for an "IDCTAB" keyword in the primary header. Returns ------- status : bool If False : MakeWCS, CompSIP and TDDCorr should not be applied. If True : there's no restriction on corrections, they all should be applied. Raises ------ IOError : If IDCTAB file not found on disk. """ try: idctab = fits.getval(fname, 'IDCTAB').strip() if idctab == 'N/A' or idctab == "": return False except KeyError: return False idctab = fileutil.osfn(idctab) if os.path.exists(idctab): return True else: raise IOError("IDCTAB file {0} not found".format(idctab)) def applyTDDCorr(fname, utddcorr): """ The default value of tddcorr for all ACS images is True. This correction will be performed if all conditions below are True: - the user did not turn it off on the command line - the detector is WFC - the idc table specified in the primary header is available. """ phdr = fits.getheader(fname) instrument = phdr['INSTRUME'] try: detector = phdr['DETECTOR'] except KeyError: detector = None try: tddswitch = phdr['TDDCORR'] except KeyError: tddswitch = 'PERFORM' if instrument == 'ACS' and detector == 'WFC' and utddcorr and tddswitch == 'PERFORM': tddcorr = True try: idctab = phdr['IDCTAB'] except KeyError: tddcorr = False if os.path.exists(fileutil.osfn(idctab)): tddcorr = True else: tddcorr = False else: tddcorr = False return tddcorr def applyNpolCorr(fname, unpolcorr): """ Determines whether non-polynomial distortion lookup tables should be added as extensions to the science file based on the 'NPOLFILE' keyword in the primary header and NPOLEXT kw in the first extension. This is a default correction and will always run in the pipeline. The file used to generate the extensions is recorded in the NPOLEXT keyword in the first science extension. If 'NPOLFILE' in the primary header is different from 'NPOLEXT' in the extension header and the file exists on disk and is a 'new type' npolfile, then the lookup tables will be updated as 'WCSDVARR' extensions. """ applyNPOLCorr = True try: # get NPOLFILE kw from primary header fnpol0 = fits.getval(fname, 'NPOLFILE') if fnpol0 == 'N/A': utils.remove_distortion(fname, "NPOLFILE") return False fnpol0 = fileutil.osfn(fnpol0) if not fileutil.findFile(fnpol0): msg = '"NPOLFILE" exists in primary header but file {0} not found.' 'Non-polynomial distortion correction will not be applied.'.format(fnpol0) logger.critical(msg) raise IOError("NPOLFILE {0} not found".format(fnpol0)) try: # get NPOLEXT kw from first extension header fnpol1 = fits.getval(fname, 'NPOLEXT', ext=1) fnpol1 = fileutil.osfn(fnpol1) if fnpol1 and fileutil.findFile(fnpol1): if fnpol0 != fnpol1: applyNPOLCorr = True else: msg = """\n\tNPOLEXT with the same value as NPOLFILE found in first extension. NPOL correction will not be applied.""" logger.info(msg) applyNPOLCorr = False else: # npl file defined in first extension may not be found # but if a valid kw exists in the primary header, non-polynomial # distortion correction should be applied. applyNPOLCorr = True except KeyError: # the case of "NPOLFILE" kw present in primary header but "NPOLEXT" missing # in first extension header applyNPOLCorr = True except KeyError: logger.info('\n\t"NPOLFILE" keyword not found in primary header') applyNPOLCorr = False return applyNPOLCorr if isOldStyleDGEO(fname, fnpol0): applyNPOLCorr = False return (applyNPOLCorr and unpolcorr) def isOldStyleDGEO(fname, dgname): # checks if the file defined in a NPOLFILE kw is a full size # (old style) image sci_hdr = fits.getheader(fname, ext=1) dgeo_hdr = fits.getheader(dgname, ext=1) sci_naxis1 = sci_hdr['NAXIS1'] sci_naxis2 = sci_hdr['NAXIS2'] dg_naxis1 = dgeo_hdr['NAXIS1'] dg_naxis2 = dgeo_hdr['NAXIS2'] if sci_naxis1 <= dg_naxis1 or sci_naxis2 <= dg_naxis2: msg = """\n\tOnly full size (old style) DGEO file was found.\n Non-polynomial distortion correction will not be applied.""" logger.critical(msg) return True else: return False def apply_d2im_correction(fname, d2imcorr): """ Logic to decide whether to apply the D2IM correction. Parameters ---------- fname : str Science file name. d2imcorr : bool Flag indicating if D2IM is should be enabled if allowed. Return ------ applyD2IMCorr : bool Flag whether to apply the correction. The D2IM correction is applied to a science file if it is in the allowed corrections for the instrument. The name of the file with the correction is saved in the ``D2IMFILE`` keyword in the primary header. When the correction is applied the name of the file is saved in the ``D2IMEXT`` keyword in the 1st extension header. """ applyD2IMCorr = True if not d2imcorr: logger.info("D2IM correction not requested - not applying it.") return False # get D2IMFILE kw from primary header try: fd2im0 = fits.getval(fname, 'D2IMFILE') except KeyError: logger.info("D2IMFILE keyword is missing - D2IM correction will not be applied.") return False if fd2im0 == 'N/A': utils.remove_distortion(fname, "D2IMFILE") return False fd2im0 = fileutil.osfn(fd2im0) if not fileutil.findFile(fd2im0): message = "D2IMFILE {0} not found.".format(fd2im0) logger.critical(message) raise IOError(message) try: # get D2IMEXT kw from first extension header fd2imext = fits.getval(fname, 'D2IMEXT', ext=1) except KeyError: # the case of D2IMFILE kw present in primary header but D2IMEXT missing # in first extension header return True fd2imext = fileutil.osfn(fd2imext) if fd2imext and fileutil.findFile(fd2imext): if fd2im0 != fd2imext: applyD2IMCorr = True else: applyD2IMCorr = False else: # D2IM file defined in first extension may not be found # but if a valid kw exists in the primary header, # detector to image correction should be applied. applyD2IMCorr = True return applyD2IMCorr