Specific instrument products and algorithm validation Prelaunch strategy

Specific instrument, products, and algorithm validation • Pre-launch strategy should focus on algorithm development (“physical validation”). Ø Preconditions : involvement of algorithm developers with info provided through EC cal/val portal and establishment of process for refining algorithms. Ø Algorithm-to-algorithm intercomparison for level 2 products. Ø Targeted measurement addressing specific algorithms parameterizations/assumptions (e. g. melting layer attenuation W band) • Post-launch strategy (3 -4 year life cycle) adds “statistical validation” with (but not exclusively ground-based instruments that establishes performances and also lack of performance in some situations Ø Geographical/products gaps: Apparently not (GIVE + regional/target measurements), heterogeneous sites (missing Australia, tropics ? ), instruments, and methods. Synergy with other projects, support from “permanent” observatory, less from operational networks. Ø Careful mapping of methods and measurements of current proposals is needed, but likely will be different at EC launch because of financial support. Do “whatever it takes” to ensure EC calval accepted proposals will be funded. Ø Standards ? Needed to avoid the differences in product performances are not due to calval instruments’ artifacts. Standards are somehow dangerous: different levels of compliance with standards could be set.