diff options
Diffstat (limited to 'wcsutil/__init__.py')
| -rw-r--r-- | wcsutil/__init__.py | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/wcsutil/__init__.py b/wcsutil/__init__.py new file mode 100644 index 0000000..46ad42e --- /dev/null +++ b/wcsutil/__init__.py @@ -0,0 +1,166 @@ +#from .. pywcs.sip import SIP +from pywcs.sip import SIP +import pyfits +import instruments +#from .. distortion import models +from hstwcs.distortion import models +import numpy as N + +#from .. mappings import inst_mappings, ins_spec_kw, DEGTORAD, RADTODEG, basic_wcs +from hstwcs.mappings import inst_mappings, ins_spec_kw, DEGTORAD, RADTODEG +from hstwcs.mappings import basic_wcs, prim_hdr_kw + +__docformat__ = 'restructuredtext' + +class HSTWCS(SIP): + """ + Purpose + ======= + Create a wcs object based on the instrument. + It has all basic WCS kw as attribbutes (set by pywcs). + It also uses the primary and extension header to define + instrument specific attributes needed by the correction classes. + """ + + def __init__(self, hdr0, hdr): + """ + :Parameters: + `hdr0`: Pyfits Header + primary header + `hdr`: Pyfits Header + extension header + """ + self.hdr = hdr + self.hdr0 = hdr0 + SIP.__init__(self, self.hdr) + self.setHDR0kw(hdr0) + self.detector = self.setDetector() + self.inst_kw = ins_spec_kw + self.setInstrSpecKw() + self.pscale = self.setPscale() + self.orientat = self.setOrient() + + + + def setHDR0kw(self, primhdr): + #sets attributes from kw defined in the primary header + self.instrument = primhdr.get('INSTRUME', None) + self.offtab = primhdr.get('OFFTAB', None) + self.idctab = primhdr.get('IDCTAB', None) + self.date_obs = primhdr.get('DATE-OBS', None) + self.pav3 = primhdr.get('PA_V3', None) + self.ra_targ = primhdr.get('RA_TARG', None) + self.dec_targ = primhdr.get('DEC_TARG', None) + + + def setDetector(self): + #sets detector attribute for instuments which have more than one detector + if self.instrument in ['ACS', 'WFC3']: + return self.hdr0.get('DETECTOR', None) + + + def setInstrSpecKw(self): + #Based on the instrument kw creates an instalnce of an instrument WCS class + #and sets attributes from instrument specific kw + if self.instrument in inst_mappings.keys(): + inst_kl = inst_mappings[self.instrument] + inst_kl = instruments.__dict__[inst_kl] + insobj = inst_kl(self.hdr0, self.hdr) + for key in self.inst_kw: + self.__setattr__(key, insobj.__getattribute__(key)) + else: + raise KeyError, "Unsupported instrument - %s" %self.instrument + + def setPscale(self): + #Calculates the plate scale from the cd matrix + #this may not be needed now and shoufl probably be done after all + # corrections + cd11 = self.cd[0][0] + cd21 = self.cd[1][0] + return N.sqrt(N.power(cd11,2)+N.power(cd21,2)) * 3600. + + def setOrient(self): + #same as setPscale + cd12 = self.cd[0][1] + cd22 = self.cd[1][1] + return RADTODEG(N.arctan2(cd12,cd22)) + + def verifyPa_V3(self): + """make sure PA_V3 is populated""" + + def verifyKw(self): + """verify that all required kw have meaningful values""" + + def readModel(self): + """ + Purpose + ======= + Read distortion model from idc table. + Save some of the information as kw needed later by pydrizzle + + list of kw - to be revised later + """ + self.idcmodel = models.IDCModel(self.idctab, + chip=self.chip, direction='forward', date=self.date_obs, + filter1=self.filter1, filter2=self.filter2, + offtab=self.offtab, binned=self.binned) + + + self.updatehdr() + + + def updatehdr(self, newkeywords=None): + #kw2add : OCX10, OCX11, OCY10, OCY11 + # record the model in the header for use by pydrizzle + self.hdr.update('OCX10', self.idcmodel.cx[1,0]) + self.hdr.update('OCX11', self.idcmodel.cx[1,1]) + self.hdr.update('OCY10', self.idcmodel.cy[1,0]) + self.hdr.update('OCY11', self.idcmodel.cy[1,1]) + self.hdr.update('IDCSCALE', self.idcmodel.refpix['PSCALE']) + self.hdr.update('IDCTHETA', self.idcmodel.refpix['THETA']) + self.hdr.update('IDCXREF', self.idcmodel.refpix['XREF']) + self.hdr.update('IDCYREF', self.idcmodel.refpix['YREF']) + self.hdr.update('IDCV2REF', self.idcmodel.refpix['V2REF']) + self.hdr.update('IDCV3REF', self.idcmodel.refpix['V3REF']) + self.hdr.update('IDCXSIZE', self.idcmodel.refpix['XSIZE']) + self.hdr.update('IDCYSIZE', self.idcmodel.refpix['YSIZE']) + self.hdr.update('IDCXDELT', self.idcmodel.refpix['XDELTA']) + self.hdr.update('IDCYDELT', self.idcmodel.refpix['YDELTA']) + self.hdr.update('CENTERED', self.idcmodel.refpix['centered']) + + + def restore(self): + """ + restores basic wcs keywords from archive + this should be modified to always return a populated + dictionary, although the values may be None. + """ + + backup = {} + for k in basic_wcs: + try: + nkw = ('O'+k)[:7] + #backup[k] = self.hdr.__getitem__('O'+k) + backup[k] = self.hdr[nkw] + #self.__setattr__(k, self.hdr.__getitem__('O'+k)) + self.__setattr__(k, self.hdr[nkw]) + except KeyError: + print 'Keyword %s not found' % k + + return backup + + def archive_kw(self): + """ + archive original WCS kw before recalculating them. + """ + backup_kw = self.restore() + if backup_kw != {}: + return + else: + # keep the archived kw 8 characters long + cmt = 'archived value' + for kw in basic_wcs: + nkw = 'O'+kw + self.hdr.update(nkw[:7], self.hdr[kw], comment=cmt) + + |