Survey of atmospheric remote sensing techniques leveraging information in passive IR spectral radiance measurements

Several techniques exist for using ground-based measurements of IR radiance to characterize the atmosphere, especially the boundary layer. These methodologies, in contrast to space based observations or active probing techniques, offer a safe, continuous measure of atmospheric parameters at a single location that are highly accurate at altitudes very near the ground (<500 m) and can be obtained without the need for human monitoring. Herein we demonstrate the use of data from a BOMEM MR 140 spectroradiometer for estimation of temperature and water vapor profiles. Temperature profiles are calculated using a simple process based on temperature invariant spectral points of downwelling mid-wave IR (MWIR) radiance; the basic algorithm was reported in 2000. Results reported here include an update to the fit algorithm as well as qualitative comparisons to field test data obtained in 1999 where an active Raman LIDAR and a balloonsonde measured the vertical temperature profile and vertical water vapor profile during an MR data collection. Once the vertical temperature profile is known, the vertical water vapor profile can be calculated using the same radiometric data. Water vapor profiles are calculated in much the same way as temperature profiles, using a simple inversion process, except different altitude points are based on temperature dependent absorption lines instead of temperature invariant points