FTIR Spectroscopy of the Atmosphere. I. Principles and Methods

In recent years Fourier transform infrared (FTIR) spectroscopy has been the dominant technique used for measuring the infrared (IR) absorption and emission spectra of most materials, with substantial advantages in signal‐to‐noise ratio, resolution, speed, and detection limits. The major advantage of the FTIR technique over other spectroscopic methods is that practically all compounds show characteristic absorption/emission in the IR spectral region and based on this property they can thus be analyzed both quantitatively and qualitatively. The quest for highly sensitive detection methods for atmospheric trace gas samples, either in laboratory setup or in outdoor remote sensing, has been on agenda for several decades. The fast and intensive development of FTIR spectroscopic techniques has propelled the progress of trace gas analysis of the atmosphere. Since the early 1970s the number and scope of FTIR atmospheric measurements has increased steadily. In this review article we are making an attempt t...