OR: The PERICLES approach to long term data preservation.

The standard for archiving space data is the OAIS (Open Archiving Information Standard). PERICLES intends to evolve this standard to the more flexible LRM (Linked Resource Model) model. In PERICLES, we refer to evolving collections of independent resources as a Digital Ecosystem (DE). Models of Digital Ecosystems are based on an abstract upper ontology, the Linked Resource Model (LRM). At its core, the LRM defines an ecosystem by means of the constituent entities and the dependencies between them. The particular focus of the LRM is on dealing with change, which can be governed by changed management policies incorporated into the model. The LRM can then be specialised to specific application areas such as space science by incorporating lower-level domain ontologies.

The LRM is a PERICLES developed concept and is described in the PERICLES deliverable: D3.3.URL: http://periclesproject.eu/deliverables/47 and is shown in the other modules. The final objective is to use this model to effectively “replay” the experiment from the stored data and in a first stage produce a new version of the final scientific data using an improved set of algorithms and calibration data bases. This is be achieved already for experiments in progress where new versions are regularly reissued; within ESA, this task is achieved by ESRIN (Frascati, Italy) for Earth Observation while space science data are archived and maintained at ESAC (Villafranca, Spain). Both centres maintain now long data series corresponding to the space age (a little more than thirty years) and which are now important for the monitoring of global changes as temperature or sea level variations.

Long

A second stage of this experiment replay is in the development of completely new products corresponding to the needs of future scientists. This will be only possible through the reuse of a much larger set of raw data, ancillary data and corresponding metadata which is the base of the PERICLES process as illustrated in figure 1.

Fig. 1: PERICLES scheme of bringing back to life a past experiment from storage to new products using the different tools developed for PERICLES and described in the other modules.