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Question:

What is the difference between the CPF Effective date and Version date?

Answer:

Calibration Parameter Files (CPFs) each have an Effective date and a Version date. The Effective date of the CPF must match the acquisition date of the scene. A CPF version is active until it is superseded by a new CPF for that date period. Data can be processed with any version of a CPF; the later versions have more refined parameters.