The processing of Radar Altimeter and ATSR/MW (microwave radiometer) data is performed in two steps.
The first step of the processing consists in transforming raw data (recorded on board the satellite) in physical quantities, time tagged, located and corrected for the instrumental effects, and in storing the following internal products:
- OIP (off-line intermediate product) for the radar altimeter: altimeter range, backscatter coefficient, significant wave height over oceansurfaces, and all instrumental corrections.
- MBT (microwave Brightness temperatures) for the ATSR/MW: microwave brightness temperatures at 23.8 and 36.5 GHz.
The second step of the processing consists in computing the environmental corrections and merging the precise orbit. The resulting data are:
- OPR (Ocean Product) for the radar altimeter : Same as OIP but enhanced with all geophysical corrections and precise orbit altitude. All the geophysical corrections are supplied together with the uncorrected measures, to allow the user the possibility of applying different corrections.
- VLC (Vapor Liquid Content) for the ATSR/MW : geophysical parameters water vapour and liquid water content.
[From "RA/ATSR products - User Manual", Ref.: C2-MUT-A-01-IF V, 2.3]
Performance and Quality
The Cyclic Reports were produced at the end of every 35-day cycle and shown the behaviour of ERS2 Microwave Radiometer in terms of instrumental characteristics and quality of the brightness temperatures. It was performed on the MWR level 0 data product (EMWC). The decoding and the pre-processing were done with the MWR level 1B reference processing chain located at CETP (Centre d'Etudes des Environnements Terrestre et Planétaire ). The data were from the Kiruna station (KS), the Maspalomas Station (MS), the Prince Albert Station (PS) and the Gatineau Station (GS).
The objectives of these documents were:
- to provide an instrumental status;
- to check the stability of the instrument;
- to report any change at the instrumental level likely to impact quality of the brightness temperatures;
- to check the stability of the brightness temperatures.