Monitoring Measurement Performance of the CryoSat SIRAL Level 2 Data Products
Muir, Alan1; Baker, Steve1; Brockley, David1; Gaudelli, Julia1; Mannan, Rubinder2; Parrinello, Tommaso3

University College London has a long involvement in the CryoSat Mission from the proposal stage, through the development of the data processing facility and continuing today in an expert support role to provide an operational monitoring and QA service for the Level 2 data products. As an ESA-designated Expert Support Laboratory for the CryoSat instrument processing facility we have validated and monitored measurement performance for all three SIRAL measurement modes since the end of the commissioning phase in October 2010. A variety of tests and monitoring processes are performed on the GDR data on each 30-day cycle corresponding to the "data takes" in the mission planning. Results are continuously accumulated and form a growing time-line which now covers 26 cycles of data. Analysis of this data set allows monitoring of the long-term drift in the SIRAL sensor performance and in the end-to-end measurement performance. All monitoring results and trend plots are available to users through our web site. Since January 2013 ESA have reprocessed the first 18-months of CryoSat data using the latest processor baseline, and so we present here for the first time the results of monitoring 3 years of SIRAL Level 2 data products, generated with the same processor, including new QA results from the Commissioning phase. This poster describes the monitoring processes applied, the anomalies they can detect and the performance metrics that can be observed to detect drifts. We also describe some of the lesser known features of the SIRAL data products. Emergent drifts in the global statistics and improvements and differences between the processing baselines are illustrated and discussed.