For the analysis of meteor spectra it is useful to generate synthetic meteor spectra and compare these with observed meteor spectra. By adjusting the intensities of different atomic species of the meteor and atmospheric oxigen and nitrogen, it is possible to disentangle the complex meteor spectra with overlapping lines. The meteor spectra also contain a thermal (blackbody) contribution and a prominent band of molecular nitrogen (the first positive band). With a least square fit all these contributions can be determined. The atomic spectra can be calculated from data at NIST (https://physics.nist.gov/PhysRefData/ASD/lines_form.html), assuming thermal equilibrium and a plasma temperature, which can also be determined with the least square fit.
The calculation has been integrated into the Python script for the processing of meteor spectra, which has been discussed here previously (https://meteorspectroscopy.org/…/creation-and-use-of-flat-field-for-meteor-spectroscopy/ and other posts in this blog).
The calculation is done on a separate page, where all the parameters for the fit can be edited and calculated:
Note that the instrument response is applied to the synthetic spectra and the fitting of the instrumental linewidth.
An application of these calculation is the determination of relative intensities of Fe-, Mg- and Na-lines by integration over the most prominent lines or line groups of these elements around 530, 515 and 590 nm and presenting these intensity ratios as a ternary plot, for some meteorspectra recorded during the last months:
The script has been published on my Github repository. Since it is still in an experimental stage, it was published as a branch synthetic_spectra. In the meantime, it has been merged into the main script (https://github.com/…/tree/master). A detailed description of the script for synthetic spectra can also be downloaded from: https://github.com/…Synthetic meteor spectra.pdf)
Spectroscopy 