get_atran¶
- sofia_redux.instruments.exes.get_atran.get_atran(header, resolution, filename=None, get_unsmoothed=False, atran_dir=None)[source]¶
Retrieve reference atmospheric transmission data.
PSG model files in the data/transmission directory should be named according to the altitude, ZA, and wavelengths for which they were generated, as:
psg_[alt]K_[za]deg_[wmin]-[wmax]um.fits
For example, the file generated for altitude of 41,000 feet, ZA of 45 degrees, and wavelengths between 5 and 28 microns should be named:
psg_41K_45deg_5-28um.fits
Model files are expected to be FITS images containing two rows. The first is wavenumber values in cm-1; the second is the fractional atmospheric transmission expected at that wavenumber.
The procedure is:
Identify model file by ZA and Altitude, unless override is provided.
Read transmission 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 model file used.
- resolutionfloat
Spectral resolution to which transmission data should be smoothed.
- filenamestr, optional
Atmospheric transmission file to be used. If not provided, a default file will be retrieved from the data/transmission directory. The file with the closest matching ZA and Altitude to the input data will be used. If an override file is provided, it should be a FITS image file containing wavenumber and transmission data without smoothing.
- get_unsmoothedbool, optional
If True, return the unsmoothed atran data with original wavenumber array in addition to the smoothed array.
- atran_dirstr, optional
Path to a directory containing model reference FITS files. If not provided, the default set of files packaged with the pipeline will be used.
- Returns:
- atrannumpy.ndarray
A (2, nw) array containing wavenumber and transmission data.
- unsmoothednumpy.ndarray, optional
An array containing wavenumber, unsmoothed transmission data, and any additional raw data rows, returned only if get_unsmoothed is set.