Geoscience Reference
In-Depth Information
Web service
—
As we wanted to be sure that the existing service could be
extended, we chose OGC Sensor Observation Service [
11
] as part of our
experimental system. The server solution consists of the implementation of
standard SOS webservice without changes in contracts and business logic (the
goal). For spatial data, Renci (Renaissance Computing Institute) OpenGIS
implementation was used to bring us API for using Gml, Ows, SensorML or
Tml speci
first version of samples we use its Core and Enhanced
extensions with GetCapabilities, DescribeSensor, GetObservation and GetFea-
tureOfInterest operations. In the future version transactional extension of SWE
SOS can be implemented especially with a proposal of one-way InsertObser-
vation operation and broadcast event that new observation arrived for all clients.
Weda API
—
cations. In the
Other projects undergoing development are WedaAPI and layers of
the Weda eventing processor (will be integrated to WedaAPI after more tests).
The WebSocket server used is RFC6455 Super-WebSocket implementation.
The Weda eventing processor integrates a Complex event processing engine
NEsper
the widely used CEP engine offering runtime for .Net. CEP server
runs independently and has its own long running lifetime over the requests.
REST-compliant Web services, in which the primary purpose of the service is to
manipulate XML representations of Web resources using a uniform set of
“
—
”
stateless
operations.
RPC-compliant Web services, in which the service may expose an arbitrary set
of operations.
WEDA-compliant Web services, in which the service can use asynchronous
message passing which can provide us eventing behaviour as well as call and
return.
3.2 Thin Client
Figure
3
shows the web client interface of our thin-client connected to the server.
Both clients read the geo-spatial data from the OGC SOS service by Weda
ChannelStack
transport and message binding and subprotocol. This client acts as
GIS Web map reader with WMS and SOS layers. It is implemented with ASP.NET
MVC3 and JavaScript using OpenLayers. We extended its Protocol.SOS javascript
library to be capable of connecting to the Weda endpoint. The use for the client is as
a public GIS Viewer system which presents SOS service data graphically upon the
public WMS layer while that data is loaded over Weda. End developers can build a
nice viewer with many features according to Weda capabilities. This client was not
considered as a benchmarking environment. Nevertheless some response time
logging is contained in source so the user can optimize the application after dis-
playing the response time information in the browser
—
'
s console.
Search WWH ::
Custom Search