Assessment and improvement of the polarisation correction algorithm of GOME

Journal article

We have studied the errors in GOME radiances resulting solely from the operational polarisation correction of GOME signals. The assessment was made by simulating on a computer both the observation of various Earth scenes and the subsequent calibration of signals, as relevant to GOME. For 290-350 nm, errors are typically larger than 1%, sometimes even as large as 10 %. Especially for 305-315 nm, errors will usually be 2-5 %. For longer wavelengths (350-790 nm), errors are normally smaller than 1%, allthough they may reach 2% for certain wavelengths and Earth scenes. The large UV errors are due to lack of UV polarisation data, either from theory or observation. We supply additional theoretical data in the form of parametrisations of the polarisation in the UV and show that a polarisation correction algorithm capable of using this additional information significantly reduces UV radiance errors. The correct retrieval of e.g. ozone profiles relies strongly on well-calibrated absolute UV radiances. Our results are also relevant to future instruments like SCIAMACHY and GOME-2.

Authors: Schutgens, N; Stammes, P

• Journal: European Space Agency, (Special Publication) ESA SP
• Issue: 461
• Pages: 2162-2171
• Publication date: 2000-01-01
• ISSN: 0379-6566
• Language: English