07/03/03 48821 CTB Converted to XML format This relation is used to link NICMOS exposures to the SAA dark association that is relevant to the exposure. If no record exists, then either the exposure is an SAA dark or the exposure occurs too long after the SAA exit time. The individual exposures of the associations can be accessed through the asn_product_link table. All the timing info for both the exposures and the darks are found in the nic_saa_exit table. For records in this table, the dark association must have nearly the same saa_exit time (from NIC_SAA_EXIT table) as the exposure. That is, the most recent SAA exit for both the darks and the exposures must be in the same orbit. The exposure from the dark association must have the same qelogsheet.config value. The qelogsheet.targname value for the dark exposures will be POST-SAA-DARK. The records in this table are inserted during the processing of the mission schedule, after updating the the asn tables. C3 When a proposal is accepted into the PMDB by SPSS it must be assigned a unique 3 character base 36 program identifier. This is done by the PMDB/ACCEPT_PROP command. This program identifier is tagged as 'program_id' in most PMDB relations. Is is used for identification of proposals by spacecraft and OPUS software. It is also used in the OPUS and DADS rootname for all archived science data files. Because of flight design software, program_id must be three characters. C2 An observation set is a collection of one or more alignments that are grouped together based on FGS pointing requirements. That is, if multiple alignments can all be executed using the same guide star pair, they are grouped into the same observation set. An observation set is identified by a 2 character base 36 string. This field, typically called 'obset_id', will often contribute to the index on relation together with a proposal_id, version_num, and possibly other fields. OBSET is an abbreviation for observation set. C2 Observations are numbered sequentially throughout an observation set and are assigned by SMS -generat. An ob_number is _NOT_ the same as an obset_ID. This field can be joined to member_num for exposure records in asn_members. C3 The program_id of the dark association. See asn_product_link.program_id. C2 Association observation set identifier of the dark association. See asn_product_link.asn_obset_id. " C3 Member number of the dark association primary product. See asn_product_link.member_num. C9 This is a convenience field. It can be reconstructed from the letter N, the dark_program_id, the dark_obset_id, and the dark_member_num. See asn_members for complete definition of association_id. SAA_LINK_TYPE NICMOS SAA Link Relation OPUS unique clustered nonclustered