Papers in PDF format

Archived Files
Start Time 1
End Time 1
S.T.2
E.T.2
S.T.3
E.T.3
Results sent to the user
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OR
Figure 2: Extraction of chronologically ordered data
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We also use standardised data descriptions based on the EAST language (Enhanced Ada SubseT) [CCSDS
1995]. This is a formal language around which certain general tools have been or are currently being
developed. The use of this tool involves two stages:
• a first stage in which the user selects the fields in which he is interested. A hierarchical tree representation
of the different data fields is constructed on the basis of the EAST description. Using this representation, users
identify and mark the fields in which they are interested through a HTML form-based interface.
• a second stage in which data is extracted from an archive and then 'filtered' so as to preserve only those
fields requested by the user [Fig. 3].
HEADER STATUS V1 ORB SFA FB FBL V2 N1 / N2 DFT spectra / WF1 /WF2
HEADER STATUS ORB SFA FBL V2 N1 / N2
Figure 3: Field extraction
Special care was taken in the design of the SADS to ensure that the proposed solution would allow for an easy
evolution, since eventually past and future space mission will store their data in this host structure. It was thus
one of our design goals to propose a solution flexible and generic enough to accommodate for yet unforeseen
storage requirements.
• The metadata database model was designed to accommodate for any data record structure, whether fixed or
variable length. It is also able to deal with various date representations.