After having reached final flight configuration, a strict configuration control mechanism is required
to maintain the operational measurement status. Such a mechanism has been introduced with the start of the routine
operations phase in the form of Operation Change Requests (OCR).
All three levels of measurement operations, i.e. mission scenarios, states and timelines are covered by the OCR mechanism. It allows to track modifications to the actual final flight configuration from the originator of the change request to the moment, when the modification becomes valid in-flight. Each SCIAMACHY program participant (user, agency, mission) may issue an OCR. The flow of the OCR is predefined and comprises:
OCRs are required for all operations modifications which cause a deviation from the final flight concept.
This is true for both permanent changes and test cases. The complete processing of an OCR as described above can be
time-consuming, particularly when modifications are required on the level of on-board state and timeline tables.
Therefore, OCRs shall always be raised well ahead in time.
A Word template of the OCR can be found here: OCR_template.doc.
Please note that changes of engineering related issues (e.g. requests for decontamination, thermal settings) do not require OCRs. They are dealt with via a separate interface between SCIAMACHY and ENVISAT/FOCC.