Type: Journal Article
Venue: Proceedings SPIE
Shelley B. Petroy, Richard E. Nicholson, Rainer M. E. Illing, Robert d'Entremont and Hilary Snell, "The impact of aerosol spatial inhomogeneity on the design and performance of spaceborne multiangular instruments", Proc. SPIE 5542, 395 (2004); doi:10.1117/12.556353
Polarimetric measurements in the VIS/NIR spectral region improve aerosol microphysical and compositional retrievals. The retrieval approaches exploit the unique polarimetric signatures of aerosols as function of scattering angle, thereby driving the requirement for data collection over a large range of scattering angles. The scattering angle coverage is a function both of the instrument/sun/target geometry and the instrument architectural approach toward acquiring multi-angular data. These two functions are important aspects of a spaceborne, multi-angular polarimetric mission. The instrument design must also consider the impact of retrieval error arising from aerosol spatial variability. For a single-pixel scanning architecture, both the pixel separation as a function of earth rotation beneath the spacecraft and the pixel growth with increasing scan angle can result in significant retrieval errors due to aerosol spatial variability. We have investigated the impact of aerosol spatial inhomogeneity on the performance of a single-pixel, along-track scanning, multi-angular polarimetric instrument operating in a low-earth orbit (LEO) such as the EOS Aqua orbit of 705 km. Possible mitigation strategies to reduce the impact of the spatial inhomogeneity on aerosol property retrieval performance are also reviewed.