get_atran¶
- sofia_redux.instruments.forcast.getatran.get_atran(header, resolution, filename=None, get_unsmoothed=False, use_wv=False, atran_dir=None, wmin=4, wmax=50)[source]¶
Retrieve reference atmospheric transmission data.
ATRAN files in the data/atran_files directory should be named according to the altitude, ZA, and wavelengths for which they were generated, as:
atran_[alt]K_[za]deg_[wmin]-[wmax]mum.fits
For example, the file generated for altitude of 41,000 feet, ZA of 45 degrees, and wavelengths between 40 and 300 microns should be named:
atran_41K_45deg_40-300mum.fits
If use_wv is set, files named for the precipitable water vapor values for which they were generated will be used instead, as:
atran_[alt]K_[za]deg_[wv]pwv_[wmin]-[wmax]mum.fits
The procedure is:
Identify ATRAN file by ZA, Altitude, and WV , unless override is provided.
Read ATRAN data from file and smooth to expected spectral resolution.
Return transmission array.
- Parameters:
- headerastropy.io.fits.header.Header
ATRNFILE keyword is written to the provided FITS header, containing the name of the ATRAN file used.
- resolutionfloat
Spectral resolution to which ATRAN data should be smoothed.
- filenamestr, optional
Atmospheric transmission file to be used. If not provided, a default file will be retrieved from the data/grism/atran directory. The file with the closest matching ZA and Altitude to the input data will be used. If override file is provided, it should be a FITS image file containing wavelength and transmission data without smoothing.
- get_unsmoothedbool, optional
If True, return the unsmoothed atran data with original wavelength array in addition to the smoothed array.
- atran_dirstr, optional
Path to a directory containing ATRAN reference FITS files. If not provided, the default set of files packaged with the pipeline will be used.
- use_wvbool, optional
If set, water vapor values from the header will be used to select the correct ATRAN file.
- wminint, optional
Wavelength minimum to match ATRAN file names.
- wmaxint, optional
Wavelength maximum to match ATRAN file names.
- Returns:
- atrannumpy.ndarray
A (2, nw) array containing wavelengths and transmission data.
- unsmoothednumpy.ndarray, optional
A (2, nw) array containing wavelengths and unsmoothed transmission data, returned only if get_unsmoothed is set.