The TROPOMI/S5P cloud properties retrieval is based on the OCRA and ROCINN algorithms currently being used in the operational GOME and GOME-2 products. OCRA retrieves the cloud fraction using measurements in the UV/VIS spectral regions and ROCINN retrieves the cloud height (pressure) and optical thickness (albedo) using measurements in and around the oxygen A-band at 760 nm. For TROPOMI/S5P we use OCRA/ROCINN Version 3.0, which is based on a more realistic treatment of clouds as optically uniform layers of light-scattering particles. Additionally the cloud parameters are also provided for a cloud model which assumes the cloud to be a Lambertian reflecting boundary. The figures below illustrate the Cloud Fraction (top panel) and the Cloud Top Pressure (lower panel) as derived from TROPOMI data from 2 January 2018.

Data product version summary (click current version number for the latest PRF).

Version number Version Effective Date Summary of Changes


Next planned update



NRTI: 2018-07-04 (orbit 03745) to present

OFFL: 2018-06-28 (orbit 03661) to present

First product release



Links to the Algorithm Theoretical Basis Document (ATBD), Product User Manual (PUM), and the Product Readme File (PRF) is provided here on the right under Documentation.