Mike Botts – January 2008 1
Supporting QA/QC inSensor Web Enablement (SWE)
and SensorML
February 2008
Mike Botts
Principal Research Scientist
University of Alabama in Huntsville
Mike Botts – January 2008 2
Why is SensorML Important?
• Importance:
– Discovery of sensors and processes / plug-n-play sensors – SensorML is
the means by which sensors and processes make themselves and their
capabilities known; describes inputs, outputs and taskable parameters
– Observation lineage – SensorML provides history of measurement and
processing of observations; supports quality knowledge of observations
– On-demand processing – SensorML supports on-demand derivation of
higher-level information (e.g. geolocation or products) without a priori
knowledge of the sensor system
– Intelligent, autonomous sensor network – SensorML enables the
development of taskable, adaptable sensor networks, and enables higher-level
problem solving anticipated from the Semantic Web
Helping the World to CommunicateGeographically
Where can QA/QC be supported?Where can QA/QC be supported?
• Sensor Descriptions (SensorML-SWE Common)
– Discovery
• Capabilities
– Detector Parameters
• Error curves, latency
• Accuracy of parameters and output values
• Observations (O&M-Swe Common)
– QA/QC expressions for the values
• e.g. accuracy, confidence levels, etc
• either constants or themselves as output values
– Lineage of the Observation (procedure property)
• SensorML System and ProcessChains
Mike Botts – January 2008 4
SensorML Descriptions for Discoverybased on QA/QC capabilities and characteristics
Mike Botts – January 2008 5
QA/QC metadata suitable for discoveryof sensors and processes
Find all remote sensor systems measuring in the visible spectral range with
ground resolution less than 20m.
Key is to define terms for QA/QC characteristics
Mike Botts – January 2008 6
QA/QC in Detectors, Actuators, and Sensor Systems
• Detector and Actuator parameters support some QA/QC
– Sensitivity, latency, error curves, etc
– Need to make certain that any additional QA/QC parameters are
supported in models
• Any SWE Common values can have QA/QC properties
– Accuracy, Confidence, etc.
– Useful for defining quality and confidence of
• Outputs of sensors
• Observation values in O&M
– quality values can be constant or defined as output of sensors and
processes
Mike Botts – January 2008 7
SensorML Supports description of Lineage for an Observation
Observation
SensorML
Within an Observation, SensorML can describe how that Observation
came to be using the “procedure” property
Key is to make sure each process component provides necessary QA/QC
measurement
Mike Botts – January 2008 8
On-demand processing of sensor data
Observation
SensorML processes can be executed on-demand to generate Observations
from low-level sensor data (without a priori knowledge of sensor system)
SensorML
Need to understand how to support error propagation within each Process
and to enable combining these errors into composite indicators