Simple quality information Data Quality

SWE Common Data Model OGC 08-094r1

6.4.3 Full lineage and traceability

Full lineage and traceability is not in the scope of this specification. It is fully addressed by the OGC ® Sensor Model Language Standard, which allows robust definition of measurement chains, with detailed information about the processing that takes place at each stage of the chain. This means that complex lineage guarantying full traceability can be recorded in a SensorML process chain, separately from the data itself. Datasets can be associated to lineage information described using the Sensor Model Language by using a metadata wrapper such as the “Observation” object defined in the OGC ® Observations and Measurements Standard OM. In this standard, the “procedure” property of the “Observation” class allows attaching detailed information about the measurement procedure, that is to say a description of how the data was obtained i.e. lineage, to the data itself.

6.5 Data Structure

Data structure defines how individual pieces of data are grouped, ordered, repeated and interleaved to form a complete data stream. The SWE Common models are based on data structures commonly accepted in computer science and formalized in ISO 11404. Classical aggregate datatypes are defined below: - Record: consists of a list of fields, each of them being keyed by a field identifier and defining its own type that can be any scalar or aggregate structure. - Array: consists of many elements of the same type, usually indexed by an integer. The element type can be any data structure including scalars and aggregates. The array size constitutes the upper bound of the index. - Choice: consists of a list of alternatives, each of them being keyed by a tag value and having its own type. Only values for one alternative at a time are actually present in the data stream described by such a structure. Requirement http:www.opengis.netspecSWE2.0reqcoreaggregates-model-valid Req 12. Aggregate data structures shall be implemented in a way that is consistent with definitions of ISO 11404. This standard also defines the concept of “data component” as any part of the structure of a dataset, aggregate or not. It is thus the superset of all the aggregate structures described above and of all scalar elements implementing the representations described in clause 6.2. Copyright © 2011 Open Geospatial Consortium 17