Proceedings Article | 18 August 2005
Proc. SPIE. 5888, Polarization Science and Remote Sensing II
KEYWORDS: Near ultraviolet, Polarization, Scattering, Aerosols, Remote sensing, Light scattering, Ozone, Atmospheric particles, Atmospheric modeling, Absorption
In the area of aerosol remote sensing, one of the more noteworthy points of the last decade has been the realization that dust and smoke can be sensed from space over land and ocean by utilizing observations of scattered ultraviolet light [Torres, et al. 1998]. The spectral contrast ratio available from the Total Ozone Mapping Spectrometer (TOMS) backscatter ultraviolet (buv) data does provide a wealth of qualitative information, such as the ability to track the global dispersion of dust and smoke from regional sources. Quantitative information, e.g. total optical depth, single scattering albedo, however, is more difficult to extract from buv data. Assumptions must be made concerning various parameters that influence buv observations, e.g. the height of the aerosol layer, surface albedo, aerosol size distribution and index of refraction. While the necessity of assumptions is due in part to the availability of only two wavelengths from historical TOMS data, these assumptions may not truly be needed for future sensors. We examine what can be gained from making measurements of polarization in addition to those of radiance (as is currently done by TOMS and its successor the Ozone Measuring Instrument, OMI, on EOS-AURA) in the TOMS spectral coverage range free from ozone absorption (340-380 nm). Measurements of the degree of linear polarization and the plane of polarization with an uncertainty of less than 0.005 would help to determine the aerosol layer height to within less than 1 km. Multi-angle measurements would also help to better utilize the polarization data by defining the particle effective radius.
