VERIFICATION OF THE RA2/MWR LEVEL 2 GEOPHYSICAL REFERENCE PROCESSORS

• Main Authors: M. P. Milagro-perez, B. Soussi, S. Baker, O. Z. Zanife, J. P. Dumont, A. Muir, B. Legresy, M. Van Den Bossche, J. Benveniste
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Hayne; Ice Sheet; Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.212.611; http://envisat.esa.int/pub/ESA_DOC/envisat_val_1202/proceedings/RA2_MWR_DORIS/05_milagro.pdf

The RA2/MWR Level 2 processing includes some algorithms designed specifically to extract geophysical measurements over different types of surfaces (ocean, sea-ice, continental ice, etc.). In order to do this, four specialised retrackers have been developed and are continuously run in parallel (over all surfaces): _ _ ocean retracker: optimised for ocean surfaces (operating on Ku and S bands), and based on a fit of the waveforms with the Hayne model _ _ ice1 retracker: optimised for general continental ice sheets. It employs an Offset Center-of-Gravity parametrisation of the Ku/S band echoes to calculate tracker offsets. This was used for ERS and will ensure measurement continuity. _ _ ice 2 retracker: optimised for ocean-like (Ku and S) echoes from continental ice-sheet interior, and based on the Brown model, _ _ sea-ice retracker: optimised to estimate a tracker offset for narrow peaked (sea-ice) echoes. It operates only on Ku band These algorithms were prototyped within CLS, LEGOS and MSSL (referred to as ESLs, or Expert Support Laboratories), and once verified, became reference processors, that were used to validate the Near Real Time and Off-Line ground operational processors (referred to as IPF and F-PAC).