Objective: MC approval of additional standard values for the PRODUCT_TYPE 
           keyword.
           Date: 2004-12-01


Background
==========

The PDS data dictionary includes the keyword PRODUCT_TYPE which has been
used to indicate "the type or category of a data product within a data
set."  However, the keyword has an inadequately populated standard value
set, not including many of those currently in use by various Nodes (PPI,
Rings). The proposal here is to make a backward compatible change to the
keyword definition (remove word "data" from text, update usage examples)
and to change the STANDARD_VALUE_TYPE from "DYNAMIC" to "SUGGESTED", in
order to facilitate a more flexible usage.


Current Urgency
===============

Very urgent

The original SCR was submitted in August, 2003. Both PPI and Rings have
been using this keyword in a manner that is inconsistent with the current
standard since that time.

Recommendations
===============

1) Change the definition of PRODUCT_TYPE to:

      "The PRODUCT_TYPE data element identifies the type or               
       category of a product within a data set.  Examples:                
       EDR, DOCUMENT, CALIBRATION_IMAGE, SPICE_SP_KERNEL, TRAJECTORY."
 
2) Change the STANDARD_VALUE_TYPE of PRODUCT_TYPE from DYNAMIC to SUGGESTED.

3) Update the standard value set to include values currently in use at 
   PPI and Rings.

Impact
======

Minimal. The inclusion of the existing PRODUCT_TYPE standard values provides
backward compatibility and allows data providers to continue using the 
keyword in current and future products.

-----------------------------------------------------------------------------
PRODUCT_TYPE Data Dictionary Element Definition
-----------------------------------------------------------------------------

   OBJECT                        = ELEMENT_DEFINITION
     NAME                        = PRODUCT_TYPE
     STATUS_TYPE                 = SUBMITTED
     STATUS_NOTE                 = "V2.0 2004-12-01 SPJ
             Revised proposal presented for technical discussion."
     DESCRIPTION                 = "
       The PRODUCT_TYPE data element identifies the type or               
       category of a product within a data set.  Examples:                
       CALIBRATED_IMAGE, SIMULATED_DATA, ENGINEERING_DATA, etc.
       
       The precise usage of this keyword varies between major data
       archives. Users should consult the appropriate PDS Discipline
       Node regarding the proper usage within the context of the 
       data set being submitted."

     SOURCE_NAME                 = "PDS PPI/S.Joy"
     GENERAL_DATA_TYPE           = IDENTIFIER
     UNIT                        = "N/A"
     VALID_MAXIMUM               = "N/A"
     VALID_MINIMUM               = "N/A"
     MAXIMUM_LENGTH              = "30"
     MINIMUM_LENGTH              = "N/A"
     STANDARD_VALUE_SET          = {DATA, SOFTWARE, DOCUMENT, 
         CALIBRATION, GEOMETRY, ANCILLARY, BROWSE, GAZETTEER, 
         INDEX, CATALOG, DICTIONARY, EDR, REDR, REFDR, UDR,
         CALIBRATED_IMAGE, CALIBRATED_QUALITY_MASK, CALIBRATION_MODEL,
         DOCUMENTATION, EDITED_DATA, EDITED_SPECTRUM, ENGINEERING_DATA,
         ENGINEERING_QUALITY_MASK, FILTER_RESPONSE, FOV_MAP, GEOMETRY_MODEL,
         GIF_BROWSE_IMAGE, JITTER, NOISE_DATA, OBSERVATION_HEADER,
         PROFILE, RAW_DATA, RAW_IMAGE, RAW_QUALITY_MASK, RING_PROFILE,
         SIMULATED_DATA, SOLAR_FLUX_DENSITY, SOURCE_DATA, SOURCE_JITTER_DATA,
         SPICE_SP_KERNEL, SUPPORT_IMAGE, TRAJECTORY, AGK, AMD, ASP, BCK,
         BSP, CCL, CPT, CSV, DCO, DCS, DKF, EDS, ECH, ECT, EDS, EOP,
         ESS, FRK, GDF, GDN, HCK, HEA, ION, IPN, LIT, LMC, LOG, LOS,
         LSK, MCH, MCT, MIF, MPD, MPF, NMC, OCH, OCS, ODA, ODF, ODR,
         OPT, PCK, PRD, RSR, SAK, SCK, SFO, SHA, SHB, SOE, SPK, SRI,
         SRG, SRT, TCK, TDF, TDL, TFK, TNF, TPH, TPS, TRO, USO, WEA}        }
     STANDARD_VALUE_TYPE         = "SUGGESTED"
     DEFAULT                     = "N/A"
     FORMATION_RULE_DESC         = "N/A"
     SYSTEM_CLASSIFICATION_ID    = COMMON
     GENERAL_CLASSIFICATION_TYPE = DATASET
     OBJECT                      = ALIAS
       ALIAS_NAME                = "N/A"
       OBJECT_NAME               = "N/A"
       USAGE_NOTE                = "N/A"
     END_OBJECT                  = ALIAS
     OBJECT                      = LOCAL_ENVIRONMENT
       SQL_FORMAT                = "CHAR(30)"
       TERSE_NAME                = "N/A"
     END_OBJECT                  = LOCAL_ENVIRONMENT
   END_OBJECT                    = ELEMENT_DEFINITION