DARE: a dedicated aerosols retrieval instrument

Satellite remote sensing of aerosols is a largely unresolved problem. A dedicated instrument aimed at aerosols would be able to reduce the large uncertainties connected to this kind of remote sensing. TNO is performing a study of a space based instrument for aerosol measurements, together with the study of up-to-date aerosol transport modeling and aerosol retrieval algorithms. Based on the study the main requirements for the aerosol spectrometer are: a spectral range from 330-1000 nm with a spectral resolution from 2 mn (UV) until > 30 nm (NIR); observation in at least 3 polarization directions (Stokes parameters); a Field of View in swath direction of > 114degrees; the wide FOV will enable daily global coverage of the earth at a ground resolution of 5-7 km(2) (Nadir) from a satellite altitude of 800 kin (polar orbit); observation in at least 3 viewing directions (wake (-53degrees), nadir (0degrees), ram (+53degrees)). The polarisation properties of the scattered light are angle dependent, from which observation of the scattered radiation at different angles gives the necessary polarisation information. The expected performance of DARE in comparison to other instruments will be discussed. (C) 2004 Elsevier Ltd. All rights reserved.