GRAS calibration / validation

Calibration will mainly consist of characterising the instrument on ground. The pre-launch characterisation look-up tables will cover the different parts of the instrument (antennas, RFCUs, GEU and Oscillator). They will then be applied for compensation in the Ground Processor facility.

Validation of Instrument products can be done at different levels: on bending angles, refractivity or temperature. Some campaigns will be settled to validate GRAS outputs with other independent sources. These other souces could be:

• Lidar
• radio-sondes
• other satellite observations
• comparisons with Numerical Weather Predictions