Accuracy of FT-Measurements of Spectral Intensities - an Issue Relevant for Remote Sensing

Abstract

In the last decade high resolution FT-IR spectrometers have become increasingly important for remote sensing of the stratosphere. While the number of observations from space and stratospheric balloons is still small there is already a large number of ground based instruments measuring ozone and a variety of important trace gases. Most of the ground based instruments work in solar occultation (transmittance measurement) within the Network for Detection of Stratospheric Change whereas instruments measuring thermal emission of radiation are rare. For source photon noise limited observation the sensitivity of an emission measurement is better if the optical band width is larger than about 1-10 cm-1. Furthermore, emission measurements have a larger versatility since they are independent from the time of day.