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NSSDC SIP Use Case. CCSDS Athens Workshop 12 April 2005. Object Exchange Information. SIP Instance List IDs of Descriptor Instances Descriptor Instance Information attributes ID of associated SLIP Instance SLIP Instance ID of the instance ID of the related Descriptor Instance
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NSSDC SIP Use Case CCSDS Athens Workshop 12 April 2005
Object Exchange Information • SIP Instance • List IDs of Descriptor Instances • Descriptor Instance • Information attributes • ID of associated SLIP Instance • SLIP Instance • ID of the instance • ID of the related Descriptor Instance • Object access attributes • Exchange Descriptor models/instances and SIP/SLIP models during submission negotiation • Then transfer SIP/SLIP Instances
NSSDC Information Items 1. Package Header Attributes Object 2. Multi-stream attributes object 3. Directory Pathname to original Data Object 4. Attributes of corresponding Data Object prior to processing 5. Attributes of corresponding Data Object after processing 6. Supplementary attributes of Data Object after processing 7. Binary Data Object stream General Packaging level Applies to Each Binary Data Object Typically multiple ‘binary’ Data Objects per package
Issues-1 • Is the current modeling approach intended to be compatible with any underlying packaging approach? • Appears to map all objects to package files • Can it map to parts of files? • e.g., attributes within an XML file? • e.g. map to NSSDC SFDU structure?
Issues-2 • If two object instances need to be paired in the transfer, can they be in separate Descriptors? • CNES example included metadata object with the data file in a single Descriptor, thereby removing need to describe this 1 to 1 relationship • State ‘matching requirement’ in an attribute as a text statement? • As done in NSSDC-SE-PKG Descriptor example?
Issues-3 • SLIP Model for NSSDC DO • AO_Metadata attribute giving companion file name included, as done in CNES example • Not clearly needed • Not included in NSSDC SLIP instance • What is CNES purpose for inclusion?
Issues-4 • SLIP Model: Object Id • Shouldn’t this be ‘Identifier distinguishing one SLIP object instance from another’ ? • Not: ‘Object Identifier (Data Object, Complementary Data Object, Collections)’
Issues-5 • SLIP Model: Last Object attribute • Is this ‘last object in this SIP’, or • last object in archive project?
Issues-6 • SLIP Model: Object Access attribute • Checksum and checksum path attributes given • What are typical values proposed for such attributes? • File with checksum and path to file? Others? • Presumably must be defined with respect to the underlying packaging mechanism?
NSSDC Partial Attribute Object -1 • BEGIN_OBJECT = NSSDC_ATTRIBUTE_OBJECT; • OBJECT_TYPE_VERSION = "3"; • BEGIN_OBJECT = PACKAGE_IDENTIFICATION; • ARCHIVAL_STORAGE_ID = "NSDC0002071385"; • PRIMARY_COLLECTION_ID = "SPMS-00216"; • DATE_TIME_OF_GENERATION = "2004-10-28T18:08:49"; • CRC_TYPE = "NSSDC_A:V0"; • ATTRIBUTE_OBJECT_CRC = "8286dac7"; • END_OBJECT = PACKAGE_IDENTIFICATION; • BEGIN_OBJECT = MULTI-STREAM_STRUCTURE; • GROUPING_RATIONALE = "Maintain Tape Image"; • GROUPING_CRITERIA = "Directory Content"; • MEDIA_ACCESSION_NUMBER = "DD000284"; • GROUPING_RECOMMENDED_NAME = "SPMS-00216_DD000284_1962-10-27"; • NUMBER_OF_STREAMS = "4"; • NUMBER_OF_BYTES_IN_CANONICAL_STREAMS = "7549776"; • GROUP_DATA_BEGIN_DATE_TIME = "1962-10-27T00:00:00.000"; • GROUP_DATA_END_DATE_TIME = "1962-11-03T00:00:00.000";
NSSDC Partial Attribute Object - 2 • BEGIN_OBJECT = STREAM_STRUCTURE; • STREAM_INSTANCE_POINTER = "1"; • DIRECTORY_PATHNAME = "./"; • BEGIN_OBJECT = ORIGINAL_STREAM_STRUCTURE; • MACHINE_REPRESENTATION = "CDC 3000"; • MEDIA_TO_DISK_REPORT = "Copied from tape to disk and passed validation"; • STREAM_TYPE = "7-BIT ASCII"; • STREAM_TYPE_TO_PACKAGER = "BINARY"; • STREAM_TYPE_FROM_DOC = "binary"; • ORIGINATING_SYSTEM = "VMS: OpenVMS Alpha OS, Version V6.2-1H3"; • DATE_TIME_CREATED = "2004-10-28T16:06:23.17"; • DATE_TIME_LAST_MODIFIED = "2004-10-28T16:06:24.53"; • FILE_ORGANIZATION = "sequential"; • RECORD_FORMAT = "variable"; • RECORD_CONTROL = "none"; • STREAM_SIZE_BYTES = "1883520"; • MAXIMUM_RECORD_LENGTH_BYTES = "0"; • FILE_NAME = "DD000284_F0001.DAT"; • CRC_TYPE = "NSSDC_A:V0"; • CRC = "0c5ca282"; • END_OBJECT = ORIGINAL_STREAM_STRUCTURE;
NSSDC Partial Attribute Object -3 • BEGIN_OBJECT = CANONICAL_STREAM_STRUCTURE; • STREAM_TYPE = "BINARY"; • STREAM_RECORD_DELIMITER = "2-BYTE HEADER"; • STREAM_SIZE_BYTES = "1887444"; • MAXIMUM_RECORD_LENGTH_BYTES = "962"; • CRC_TYPE = "NSSDC_A:V0"; • CRC = "8cb05216"; • RECOMMENDED_FILE_NAME = "DD000284_F0001.DAT"; • PROCESSING_REPORT = "FsGET_FN-P_VNA PASS: found no carriage control with variable ASCII records, AIPGEN-W_BA WARN: expected BINARY, but found only ASCII"; • FORMAT_IDENTIFIER = "NSSD1001"; • ORDERED_APPLIED_ENCODINGS = "none"; • ID_OF_ENCODED_FORMAT = "NSSD1001"; • END_OBJECT = CANONICAL_STREAM_STRUCTURE; • BEGIN_OBJECT = SUPPORTING_ATTRIBUTES; • DATA_BEGIN_DATE_TIME = "N/A"; • DATA_END_DATE_TIME = "N/A"; • END_OBJECT = SUPPORTING_ATTRIBUTES; • END_OBJECT = STREAM_STRUCTURE;