  Dual-comb spectroscopy is a rapidly developing technique that enables moving
parts-free, simultaneously broadband and high-resolution measurements with
microseconds of acquisition time. However, for high sensitivity measurements
and extended duration of operation, a coherent averaging procedure is
essential. To date, most coherent averaging schemes require additional
electro-optical components, which increase system complexity and cost. Instead,
we propose an all-computational solution that is compatible with real-time
architectures and allows for coherent averaging of spectra generated by
free-running systems. The efficacy of the computational correction algorithm is
demonstrated using spectra acquired with a THz quantum cascade laser-based
dual-comb spectrometer.
