Objective: MC approval of additional standard values for the PRODUCT_TYPE 
           keyword.
           Date: 2004-07-23


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 is defined to have a "static" standard value set and
the list of acceptable values does not include many of those currently in
use by carious 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 "static" 
to "dynamic".


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 STATIC to DYNAMIC.

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 2004-07-23 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:                
       EDR, DOCUMENT, CALIBRATION_IMAGE, SPICE_SP_KERNEL, TRAJECTORY."

     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
         }
     STANDARD_VALUE_TYPE         = "DYNAMIC"
     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