Title : Spectroscopic broadening study of H2S in submm region using Laser Heterodyne spectrometer
Authors : K. Vinay, D. Hemant
Abstract :
The structure of molecular spectral lines contained the detailed features of the investigated region.
The retrieval of the detail information from the individual spectral line shapes requires high-
resolution spectroscopic analysis of the concerned molecule in a controlled laboratory
environment. The prior determination of the line parameters from the laboratory experiment reduces
the number of the adjustable parameters in the retrieval model and hence considerably increases the
accuracy of the recovery of the other atmospheric parameters. Detection and measurement of molecular
line spectra by heterodyne spectrometer is the most powerful experimental method. The narrow
apparatus function of the heterodyne spectgrometer allows recording the line shape without any distortion.
It is an effective tool to predict the detailed characteristic features of molecules. Due to minimum overlapping
of the molecular transitions in the submm wave region highly reliable information can be retrieved from a
molecular system.
At present, following investigations being carried out :
. To measure the shifting parameters of H2S (pollutant gas) line centres by pressure of N2 air Air
. to measure the value of line pressure and temperature broadening parameters and
. To refine the line strength under high resolution.
The air broadening (perturbing molecules) study of H2S has been done taking the Earth atmosphere
into consideration. Since the air broadening parameters y air and their temperature exponents
dominate the error budget in the information retrieval, high resolution laboratory measurement of the lines
will bring great improvements to the retrieval accuracy. Latest results will be presented in the meeting.