Calval

Instruments calibration and data quality monitoring

Calval (CALibration / VALidation) is what determines data quality. This step involves a series of quality controls designed to ensure a continuous supply of data.

Calval teams calibrate the satellite instruments and determine the parameters, corrections, bias and so on to be applied to measurements. In particular, this task involves validating and refining algorithms in close collaboration with processing system development teams and users.

Once the mission is fully under way, routine Calval operations consist in determining data quality and keeping a check on instrument drift. Quality control is achieved through statistical data analysis, analyses at crossover points, and comparisons between orbit cycles. Data are also compared with other missions and with in situ sites and networks.

Description of the sections

"Overview" describes the validation activities needed before the dissemination of the data

"Latest results" provides the most recent reports (annual reports, executives summaries) for each mission and from the orbit and in-situ comparisons

"Mission performances" gives acces to the annual reports and the cyclic reports

"In-situ" is dedicated to  the in-situ calibration and validation activities

"Wind/waves" is a short section about the validation of wind and wave altimetry data.

"Cryosphere" introduces the ice validation for Antarctic and Greenland continent.

"Orbit" gives information about the Precise Orbit Determination verification.

"Syntheses of past reports" is a set of pages writen from validation reports issued between 2011 and 2016 

Calval Plans

  • Saral/AltiKa Joint Calval Plan (pdf): This is the plan objective for Saral satellite during and beyond the calibration/validation phase, conducted by the two partners Cnes and Isro project teams.

In situ comparisons

  • dedicated sites and campaigns
  • global analysis (comparison with tide gauge network)

Other calval activities: