File mdi_sheet3.txt -- Last modified Wed Sep 27 17:31:16 1995



                   COMMISSIONING PHASE BLOCK SHEET

1. INSTRUMENT AND BLOCK NUMBER: MDI, Block 3

2. BLOCK IDENTIFICATION: MDI Calibrations

3. PURPOSE: Calibrate MDI Observables

4. SUB-BLOCKS: (see Note 1)
   NR.   IDENTIFICATION

   3.1 ISS Calibration
   With MDI in ISS diagnostic mode, a systematic set of performance
   measurements will be made using different servo gains, polarizations, 
   and calibration vs. observing mode settings. 

   3.2 Sensitivity Calibrations
   Measurements for light transfer, residual image, stray light and other 
   properties will be made using DEP sequences such as TAP4x4.

   3.3 Imaging Calibrations
   Measurements for focus, image quality, distortion, and (internal) image 
   motion will be made using DEP sequences such as BURST1x1.

   3.4 Flat Field
   Several datasets for deriving flat fields will be collected using 
   telecommand sequences which move the legs and/or PZT's while taking time 
   series of granulation images.

   3.5 Michelson Tuning Calibration
   An 8-hour time series of tuning calibration images will be collected 
   using DEP sequence TAP4x4, with obs and cal mode data interspersed.

   3.6 Optical System Thermal Calibration
   Three consecutive days of calibrations similar to 3.5, with the 
   temperature setting of the filter oven raised one step at the start of
   the pass on day 2 and set back to nominal the next day. 

5. SUB-BLOCKS TABLE: (see Note 2)
   NR. - DURATION - PREVIOUS - COMMANDING - TELEMETRY - POINTING
   3.1    1:00        Nom.       NRT-d        H2 (3)      Nom. 
   3.2    2:00 (1)    Nom.       NRT-s (2)    H2 (3)      Nom.
   3.3    2:00 (1)    Nom.       NRT-s (2)    H2 (3)      Nom., No-I
   3.4    2:00        Nom.       NRT-d        H2 (3)      Nom. 
   3.5    8:00       X 3.2-4     NRT-s (2)    H2 (3)      Nom. 
   3.6  3 x 8:00     X 3.2-4     NRT-s        H2          Nom. 

   (1) Sub-blocks 3.2-3 could be done in multiple blocks of at least 1
       hour each, as long as the total is 4 hours.

   (2) Uplink of a few short (< 10 minute) delayed command files during
       the previous 1-3 days before execution of sub-blocks 3.2, 3.3,
       and 3.5 is also required. These load the observing sequences to
       be used.

   (3) VC2 data is required shortly after the start of each sub-block
       execution for 10 minutes minimum (30-60 minutes desired).

6. SCHEDULING REQUIREMENTS: (see Note 3)
   3.4 should be at least 2 days after completion of 3.3.
   3.5 requires a full 8-hour pass for observing but at most 1/2 hour
       of NRT commanding will be needed to start it.  It must be done
       on a day when the S/C pointing has been nominal for the previous
       2 days at least, for thermal stability reasons.
   3.6 requires full 8-hour passes on three consecutive days.
       Spacecraft pointing must be nominal for the day before and all 3
       days of the test, for thermal stability reasons.

7. SPECIAL REQUIREMENTS: (see Note 4)
   Sub-block 3.4 involves some motion of MDI on its legs, which may 
   generate some low-level pointing disturbance.

8. SUCCESS CRITERIA AND/OR EXPECTED OUTPUT:
   MDI initially calibrated (pending the joint offset pointing 
   calibrations in Block 6) 

9. RELEVANT PROCEDURES
   N/A

10. CROSS-REFERENCE TO TEST SHEETS: (list identifiers for test sheets)
    TBS

11. RELEVANT SECTION OF TIMELINE (backpage)

    The old time-line is now obsolete and so is not reproduced here.  This 
    block was largely derived from sub-block 3.5 of the previous version.