Information Technology Reference
In-Depth Information
20.3 Preservation Aim
The core of the CASPAR dedicated testbed is the preservation of the ability to pro-
cess data from one level to another, that is the preservation of GOME data and of all
components that enable the operational processing for generating products at higher
levels.
20.4 Preservation Analysis
A brief analysis involved looking at various possibilities including:
-
Preserving the hardware and operating systems on which to run the processing
software
-
Discarding the software not needed
-
Preserving the processing software
This last option is the one chosen and a Designated Community was decided as one
which understood how to run software and had knowledge of C.
As first demonstration case, it has been decided to preserve the ability to produce
GOME Level 1C data starting from Level 1 data; at this moment the ESA testbed is
able to demonstrate the preservation of this GOME processing chain at least against
changes of operating system or compilers/libraries/drivers affecting the ability to
run the GOME Data Processor.
The Preservation Scenario is the following: after the ingestion in the CASPAR
system of a complete and OAIS-compliant GOME L1 processing dataset, some-
thing (e.g. OS or gLib version) changes and a new L1->L1C processor has
to be developed/ingested to preserve the ability to process data from L1
to L1C.
So we must cope with changes related to the processing by managing a correct
information flow through the system, the system administrators and the users, using
a framework developed using only the CASPAR components.
20.5 Scenario ESA1 - Operating System Change
The update phase shown in Fig.
20.3
, can be summarized as follows:
1. OS Change - an external event affects the processor and an Alert is forwarded to
the ESA System Administrator.
2. The System administrator uses the Software Ontology to see which are the
modules that need to be recompiled and updated. CIDOC-CRM defines the
relationships between the modules.
