Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.stsci.edu/itm/1999-02/ITM_1999_02.pdf Дата изменения: Mon Apr 5 23:00:45 1999 Дата индексирования: Sat Mar 1 07:58:36 2014 Кодировка: Поисковые слова: mercury program

Internal Technical Memorandum ITM-1999-02

Procedures for Developing Calibration Programs
Denise Taylor, Calibration Manager March 1, 1999

ABSTRACT
This document describes procedures and suggestions for submission, implementation, and scheduling of calibration programs.

1. Introduction
The Cycle 7 calibration program implementation and scheduling did not run smoothly for Presto, especially with the newer instruments. Three factors contributed to the problems: (1) The large number of additional calibration programs that were added after the initial and delta Director's Reviews, (2) The short timespan between submission and desired execution of these additional programs, and (3) The lack of adherence to approved orbit allocations. The Program Coordinator (PCT) and Science Planning and Scheduling (SPST) teams had difficulty properly implementing and scheduling the calibration programs, and the Long Range Planning Group (LRPG) could not track the fluctuation of internal and external orbits needed for calibrations. This memo describes the procedure and timeline for submitting calibration proposals to ensure their proper implementation, scheduling, and execution. These guidelines do not differ widely from current procedures, but simply restate in one document the procedures that have been generally understood and orally agreed upon. Following these guidelines will assure the correct implementation and scheduling of the calibration programs in upcoming Cycles.

2. Director's Office Review of Calibration Plans
At the start of an observing Cycle, each instrument team evaluates the submitted GO and GTO proposals for necessary calibrations. The teams also identify any calibrations needed to characterize the operation of each instrument, especially for any new ones. These calibration programs are submitted to the Director's Office (DO) for review and acceptance. The submission includes a summary of the observations and the number of internal and external orbits needed for the upcoming Cycle. Calibration programs that are accepted by the DO are assigned a PC and then submitted to Presto through RPS2. They become part of the PCs' normal load with GO and GTO proposals for the Cycle.

3. Adding Calibration Programs to the Approved Plan
After the DO review of the calibration plan, additional calibration observations may be requested through the Telescope Time Review Board (TTRB). An instrument team submits a request to the

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Internal Technical Memorandum ITM-1999-02 TTRB for a new calibration, with a justification for the additional orbits and a summary of the observations. The TTRB reviews the request and makes a recommendation to the DO whether the extra orbits for the new calibration should be granted. Once accepted, the Calibration Manager assigns the new program an ID number and a PC. The PCs who were assigned to the original load of calibration programs are the ones most likely to be assigned to these additional programs. This is not a problem when the number of additional programs is low and the number of orbits is small. But when the number of programs is high or the proposals are large, the PCs' workload can become overwhelming, forcing proposal assignments to be reorganized within the team in order to ensure correct and timely implementation of all programs. This causes confusion and frustration to the PIs and CSs of the reassigned proposals, and unnecessary work for a PC to become familiar with another PC's previous processing. Additional calibration programs must be submitted to the TTRB at least 8 weeks before the desired execution time. The lead time of 8 weeks allows for review by the TTRB (1 to 2 weeks), submission by the SI team and implementation by the PC (1 to 3 weeks), before handing over the observations to SPST for calendar building at the required 3.5 weeks prior to execution. Unexpected onboard changes to SI operations may lead to an exception in the 8 week lead time, and every effort will be made to accommodate such an emergency.

4. Changing Existing Calibration Programs
Changes to any calibration proposal must be submitted to the assigned PC at least 6 weeks before execution. If the changes require an increase in the orbit allocation, the change request must be submitted to the TTRB at least 8 weeks before the desired execution time. The LRP plans and tracks both internal and external calibration observations, along with the GO and GTO observations. Submissions of numerous additional calibration programs through the TTRB can cause instability in the LRP, making it difficult to maintain observation plan windows. Even internal observations must be tracked to ensure enough scheduling time in the weekly timeline. Therefore, programs must adhere to approved orbit allocations.

5. Special Calibration Programs
An abnormally large number of calibrations for Cycle 7 required special commanding. The PC team was fortunate to have a member who had the expertise needed for the special processing of these proposals. This is not the case anymore; the implementation of these proposals will be difficult, if not impossible, on a routine basis. However, procedures and software are currently being reviewed to implement changes that will remove the need for the majority of this special commanding. These changes should be operational before they are needed for the execution of the Cycle 8 calibration programs.

6. Guidelines for Writing Calibration Programs
To ensure more accurate and efficient implementation and scheduling of calibration programs, it is strongly recommended that the following points be adhered to during their writing: 1. For routine, Cycle-long monitoring programs, the Special Requirement SCHED 100 should be included on all Visits. 2. All Visits that need to be executed together should be in the same program (especially decons and anneals and their associated monitors).

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Internal Technical Memorandum ITM-1999-02 3. All scheduling requirements should be included as Visit-level Special Requirements whenever possible (BETWEEN, AFTER, BEFORE, SEQ WITHIN, etc.). 4. Submission must be through RPS2.

7. Summary
It is Presto's goal to implement, schedule, and execute calibration programs as correctly and efficiently as possible. With the decreasing number of Program Coordinators in upcoming Cycles, these procedural guidelines will make this goal easier to attain. The most important points to consider for calibration programs are · Calibration programs added after the Director's Office Review must be submitted to the TTRB at least 8 weeks prior to execution; · All changes to calibration programs must be submitted at least 6 weeks prior to execution; · All calibration programs must be submitted through RPS2, and must contain all necessary scheduling requirements.

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