HITRAN is an acronym for high-resolution transmission molecular absorption database.
The HITRAN compilation of the SAO (HIgh resolution TRANmission molecular absorption database) is used for predicting and simulating transmission and emission of light in atmospheres. It is the world-standard database in molecular spectroscopy. The journal article describing it is the most cited reference in the geosciences. There are presently about 5000 HITRAN users world-wide.
Its associated database HITEMP (high-temperature spectroscopic absorption parameters) is accessible by the HITRAN website.