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use of graphic filters e.g. blurring as a generic mechanism for localised colour manipulation.
Note: Currently, the SensorSA suggests that the use of colour, transparency and texture are the best candidates for representing uncertain information for static maps in an efficient
manner. Therefore, these techniques will be further researched in the context of the Map and Diagram Service. The other techniques will remain only as concepts due to the complexity of
implementing such graphically demanding techniques in the Map and Diagram Service.
10.6.4 Unit conversion
Unit conversion in a SANY sensor network can be handled in two ways: 1. Each service offers a set of units in which it is able to provide its values andor
perform its operations. The clients can select one of the offered units if multiple are provided, and then must do all remaining unit conversions if necessary on
their own.
2. All of the functionality described in 1 above, plus a dedicated Processing Service see section 8.4.2 that can be used by client applications and services acting as
clients to perform unit conversions that they are not able to do on their own. Note: Unit conversion is considered to be part of the pre- or post-processing steps in a
processing chain see section 10.9.1.2.
10.7. Handling of large data sets
Data access in the SensorSA is provided mainly through instances of Sensor Observation Services. Depending on the application scenario fairly large amounts of data may be needed and
thus handled by those services. When working with large amounts of data, the following scenarios can be distinguished:
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Accessing a large block of data all at once
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Accessing a smaller piece of a large data set
10.7.1 Accessing large data blocks
The Sensor Observation Service see section 8.2.2 and its accompanying Observation and Measurement data model see section 7.3 provide multiple mechanisms for transporting the
actual observation data in response to a request, specified in the responseMode parameter. While some of them e.g. inline are only suitable for smaller sets of data, the observation data can also
be transported separately from the getObservation result out-of-band, which in this case only provides a description of the data and a pointer e.g. an URL to the data themselves.
The data themselves can be transported in any form andor encoding that is suitable for the specific application scenario. An example would be offering the data binary encoded with
SANY D2.3.4 Specification of the Sensor Service Architecture V3 Doc.V3.1
Copyright © 2007-2009 SANY Consortium Page 205 of 233
NetCDF http:www.unidata.ucar.educontentsoftwarenetcdfindex.html and transported using OPeNDAP http:opendap.org as shown below section 5.4 of Cox, 2007.
?xml version=1.0 encoding=UTF-8? om:Observation gml:id=timeSeries1 ... references omitted ...
gml:descriptionObservation test instance - time seriesgml:description gml:nameTime series 1gml:name
om:samplingTime gml:TimePeriod gml:id=ts1t
gml:beginPosition2005-06-17T09:00:00+08:00gml:beginPosition gml:endPosition2005-06-21T09:00:00+08:00gml:endPosition
gml:TimePeriod om:samplingTime
om:procedure xlink:href=urn:ogc:object:feature:Sensor:BOM:t_2a om:observedProperty
xlink:href=http:sweet.jpl.nasa.govontologyproperty.owlTemperature om:featureOfInterest xlink:role=urn:ogc:def:featureType:OGC:Station
xlink:href=http:my.big.orgfeature?type=station26name=st1 om:parameter
swe:Quantity definition=http:sweet.jpl.nasa.govontologyproperty.owlElevation
swe:uom xlink:href=urn:ogc:def:uom:UCUM:m swe:value3.45swe:value
swe:Quantity om:parameter
om:result xlink:href=http:www.flakey.orgopendap378.cdf om:Observation
10.7.2 Accessing small pieces of a large data set
