Towards a Solution for the Public Web-Based GIS Monitoring and Alerting System - Geoinformatics for Intelligent Transportation - page 123

3 Experimental System

We have built two experimental systems with WEDA API.

Experience and data obtained from these experiments were used for calibrating the
model. Both experimental systems use the same server-side implementation and
only client implementations differ as one was developed as a thick client and the
other as a thin client (Fig. 2 ).

“ GIS on the web ”

3.1 Server Side

The server side consists of a database layer, data access layer, web-service and
server-side Weda API.

￿ Database layer —

Sensor data is stored in the spatial database Observations Data
Model (ODM). Version 1.1 [ 10 ] is a generic template for the observations DB.
For example the SpatialReferences table provides speci cations of the location of

an observation site to record the name and EPSG code of each spatial reference
system used. The database was running inside a MSSQL 2008 environment. We
used more types of data, for example hydrologic data from CUAHSI-HIS.
￿ Data access layer —

Our data access layer provides us mapping of conceptual
schema to data schema, isolation from the relational database and database
schema and other features.

Fig. 2 Overview of experimental systems