Below are potential SIS's that interface with Instrumental Calibration
and Frame Co-addition only. Some are TBD as they depend on the details 
of processing. Some are already written:

WSDC D-I005: pre-flight calibration receivables (ICAL input) 
WSDC D-I101: frame mask-bit definitions (ICAL output) 
WSDC D-I102: refined WCS/distortion/QA information (AWAIC input) 
WSDC D-I105: level-1 frame QA metrics and diagnostics (ICAL output)
WSDC D-I106: ingest / level-0 frame pixel statistics (ICAL input)
WSDC D-I121: level-3 (Atlas Image) QA metadata (frame co-adder output)


Inputs to Instrumental Calibration (needed to support processing):
------------------------------------------------------------------

   -Metadata/keywords to level-0 FITS headers from ingest.

   -Specific H/K and PEF information to level-0 FITS headers
    or other to support dynamic calibration creation and application.

   -QA metrics on level-0 frames to warn of noisy, corrupt, 
    radhit infested data. Written (WSDC D-I106). 

   -Format specifications for pre-flight calibration receivables.
    Written (WSDC D-I005).


Outputs from Instrumental Calibration (interface with downstream modules):
--------------------------------------------------------------------------

   -Instrumentally calibration frames (level-1a-int), format and content.

   -Corresponding uncertainty frames (level-1a-unc), format and content. 

   -Corresponding mask frames (level-1a-msk), format and content.
    Mask bit-definitions for numerous downstream modules. 
    Written (WSDC D-I101).

   -QA diagnostics/metrics/plots for QA subsystem.
    Written (WSDC D-I105).

   -FPG/metadata specifications and Science Team concurrence.
    (to propagate to level-1b's + archive) 


Inputs to Frame Co-addition (needed to support processing):
-----------------------------------------------------------

   -Refined WCS and distortion information to level-1b FITS headers. 
    Source: PREX wrappers. Written (WSDC D-I102).

   -QA metrics from PREX processing on refined pointing quality/accuracy.
    If frame has no/bad ICRS solution, don't include in co-add.


Outputs from Frame Co-addition (interface with downstream modules):
-------------------------------------------------------------------

   -level-2a single-frame distortion corrected and interpolated 
    products: intensity, coverage and uncertainty images.

   -Level-3 (pre-FPG) Atlas Image products: intensity, coverage and 
    uncertainty images.

   -QA diagnostics/metrics/plots for QA subsystem. Written (WSDC D-I121).

   -FPG/metadata specifications and Science Team concurrence
    (to propagate to archive).
    Written informally.

   -Specifications to support WISE image/pixel server


--
F. Masci, 12/09/2008