5.2 Information logistics in centre-to-centre
communication
A main objective of the IOC Tsunami Programme is the integration
of national TWS towards ocean-wide networks of
early warning systems to ensure information exchange during
tsunami events. The centre-to-centre communication in a
system-of-systems requires a new generation of interoperable
message products introduced by Lendholt et al. (2012).
The information flow in a system-of-systems setup between
warning centres combines up- and downstream information
flow of a standalone system (Fig. 7). Therefore, message exchange
in crisis situations relies on both
– sensor measurements such as sea level data and earthquake
measurements; however, only pre-processed and
verified data will be exchanged to ensure reliability and
confidence among the different centres. As discussed,
the OGC SWE standards are best suited to communicate
sensor data and observations.
– warning products such as tsunami bulletins: bulletins
are disseminated by authorities in the context of international
warning networks and serve other warning centres
in decision processes. As discussed, CAP serves
all needs to transport both human readable messages
as well as structured information for (automatic) postprocessing
by other centres.
For setting up a network of TWS, the challenge is to combine
both protocols into a common message format. This is
realized by using EDXL-DE as container format for both
message types. Special attention must be drawn to the spatial
reference scheme used in tsunami bulletins. In national
systems the coastal forecast points (CFP) are used by simulations
as reference points for the wave propagation. These
points are mapped to administrative units or coastal forecast
zones (CFZ) to establish an adequate and well-known
spatial reference for warning dissemination. However, in the
international context such proprietary solutions are not suitable.
Therefore, Intergovernmental Coordination Group for
the Indian Ocean Tsunami Warning and Mitigation System
(ICG/IOTWS) has introduced a standardised set of CFZs
for the Indian Ocean to ensure interoperability among interlinked
warning centres. The DEWS project has implemented
a prototype for centre-to-centre communication based on
these precedent-setting concepts (further details in Lendholt
et al., 2012).