Calculate Photometry Keywords from IMPHTTAB

This module includes utilities for calculating the photometry keywords PHOTZPT, PHOTFLAM, PHOTPLAM, and PHOTBW for a given observation mode (obsmode) and IMPHTTAB. The calculations are performed in the same way here as they are in HSTCAL pipeline.

To calculate a single set of keywords use the function get_phot_pars().

If you are calculating for several obsmodes from a single IMPHTTAB file it’s best to use the GetPhotPars class. For example:

get_phot = GetPhotPars(imphttab)
for obs in obsmodes:
    photzpt, photflam, photplam, photbw = get_phot.get_phot_pars(obs)
    ...
get_phot.close()
class reftools.getphotpars.GetPhotPars(imphttab)

Class to be used to get photometry parameters from a given IMPHTTAB reference file. Initialize with the name of an IMPHTTAB reference file and then call this class or the get_phot_pars() method with a complete obsmode to get the photometry parameters.

Example obsmodes are:

  • 'acs,wfc1,f625w,f660n'

  • 'acs,wfc1,f625w,f814w,MJD#55000.0'

  • 'acs,wfc1,f625w,fr505n#5000.0,MJD#55000.0'

Parameters

imphttab (str) – Filename and path of IMPHTTAB reference file.

imphttab_name

Filename and path of IMPHTTAB reference file. Same as input imphttab.

Type

str

imphttab_fits

Open HDUList object from imphttab.

Type

astropy.io.fits.HDUList

close()

Close imphttab_fits attribute.

get_phot_pars(obsmode)

Return the required keywords for the specified obsmode.

Parameters

obsmode (str) – Observation mode string.

Returns

results_dict – Dictionary of photometry keyword results. Each key corresponds to one keyword and its value.

Return type

dict

exception reftools.getphotpars.ImphttabError

Class for errors associated with the imphttab file.

reftools.getphotpars.get_phot_pars(obsmode, imphttab)

Return PHOTZPT, PHOTFLAM, PHOTPLAM, and PHOTBW and any other keywords outlined in the table for specified obsmode and imphttab.

Parameters

  • obsmode (str) – Complete obsmode string including any parameterized values. For example obsmodes, see GetPhotPars.

  • imphttab (str) – Path and filename of IMPHTTAB reference file.

Returns

results_dict – Dictionary containing the photometric keyword results.

Return type

dict