Observations and Measurements (O&M) is an international standard which defines a conceptual schema encoding for
observation
Observation is the active acquisition of information from a primary source. In living beings, observation employs the senses. In science, observation can also involve the perception and recording of data via the use of scientific instruments. The ...
s, and for features involved in sampling when making observations. While the O&M standard was developed in the context of
geographic information system
A geographic information system (GIS) is a type of database containing Geographic data and information, geographic data (that is, descriptions of phenomena for which location is relevant), combined with Geographic information system software, sof ...
s, the model is derived from generic patterns proposed by Fowler and Odell, and is not limited to
geospatial information
Geographic data and information is defined in the ISO/TC 211 series of standards as data and information having an implicit or explicit association with a location relative to Earth (a geographic location or geographic position).
It is also cal ...
. O&M is one of the core standards in the
OGC Sensor Web Enablement suite, providing the response model for
Sensor Observation Service The Sensor Observation Service (SOS) is a web service to query real-time sensor data and sensor data time series and is part of the Sensor Web. The offered sensor data consists of data directly from the sensors, which are encoded in the Sensor Model ...
(SOS).
Observation schema
The core of the standard provides the observation schema. An ''observation'' is an act that results in the estimation of the value of a feature property, and involves application of a specified procedure, such as a sensor, instrument, algorithm or process chain. The procedure may be applied in-situ, remotely, or ex-situ with respect to the sampling location. Use of a common model for observation metadata allows data to be combined unambiguously, across discipline boundaries. Observation details are also important for data discovery and for data quality estimation. An observation is defined in terms of the set of properties that support these applications.
O&M defines a core set of properties for an observation:
* feature of interest
* observed property
* result
* procedure – the instrument, algorithm or process used (which may be described using
SensorML
SensorML is an approved Open Geospatial Consortium standar and an XML encoding for describing sensors and measurement processes. SensorML can be used to describe a wide range of sensors, including both dynamic and stationary platforms and both in- ...
)
* phenomenon time – the real-world time associated with the result
* result time – the time when the result was generated
* valid time – the period during which the result may be used
The key to the model is the division of the observation and its feature of interest, separating the concerns so that the appropriate information associated with the description of each object. This allows a unified treatment of ''in situ'', ''ex-situ'', and remote-sensed observations. The observation schema may also be understood as a corollary of the
General Feature Model from ISO 19101, providing metadata associated with the estimation of the value of a feature property. The Observation model takes a user-centric viewpoint, emphasizing the semantics of the feature-of-interest and its properties. This contrasts with sensor oriented models such as
SensorML
SensorML is an approved Open Geospatial Consortium standar and an XML encoding for describing sensors and measurement processes. SensorML can be used to describe a wide range of sensors, including both dynamic and stationary platforms and both in- ...
, which take a process – and thus provider-centric viewpoint.
Many observations are made to detect the variation of some property in the natural environment, expressed as a spatial function or ''field'', also known as a ''coverage'' (ISO 19123:2005). The relationship between observations, features and coverages is explained, in the context of ocean observations and modeling, in a report for
GEOSS
The Global Earth Observation System of Systems (GEOSS) was built by the Group on Earth Observations (GEO) on the basis of a 10-Year Implementation Plan running from 2005 to 2015. GEOSS seeks to connect the producers of environmental data and decisi ...
Architecture Implementation Pilot 3.
Sampling features
The standard also provides a schema for Sampling Features. Observations commonly involve sampling of the ultimate feature of interest. Specific sampling features, such as station, specimen, transect, section, are used in many application domains, and common processing and visualization tools are used. The standard defines a common set of sampling feature types classified primarily by spatial dimension, as well as samples for ex-situ observations. The schema includes relationships between sampling features (sub-sampling, derived samples).
The core properties of sampling features are:
* sampled feature – which links the sampling artefact with the real-world feature of interest
* related observation
* related sampling feature – linking sampling features into complexes
Implementations
An
XML
Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing arbitrary data. It defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. T ...
encoding (
GML Application Schema) is provided for transfer of data:
Observation schema (XSD)Sampling features (XSD)
A
JSON
JSON (JavaScript Object Notation, pronounced ; also ) is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects consisting of attribute–value pairs and arrays (or other ser ...
encoding is provided for transfer of data:
JSON Schema
An explicit
OWL
Owls are birds from the order Strigiformes (), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers a ...
representation of O&M is available:
Observation schema (OWL2)
Sampling features (OWL2)
Th
W3C Semantic Sensor Network Ontologyprovides an updated
OWL
Owls are birds from the order Strigiformes (), which includes over 200 species of mostly solitary and nocturnal birds of prey typified by an upright stance, a large, broad head, binocular vision, binaural hearing, sharp talons, and feathers a ...
implementation that covers most of O&M
.
Version 2.0 of the Observations Data Model ("ODM2"), developed by the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI) and the
Critical Zone Observatory
Critical Zone Observatories (CZO) is an interdisciplinary collaborative research project across nine institutions with the purpose of understanding the chemical, physical, geological, and biological processes that both shape the surface of Earth ...
project, adapts O&M.
ODM2 model and software
Related documents
O&M is also published as a topic of the
Open Geospatial Consortium
The Open Geospatial Consortium (OGC), an international voluntary consensus standards organization for geospatial content and location-based services, sensor web and Internet of Things, GIS data processing and data sharing. It originated in 1994 ...
''Abstract Specification''.
The previous version of O&M
Version 1 factored the model into two documents: Part 1 described the Observation Schema, and Part 2 described Sampling Features.
See also
*
Observation
Observation is the active acquisition of information from a primary source. In living beings, observation employs the senses. In science, observation can also involve the perception and recording of data via the use of scientific instruments. The ...
*
Semantic Sensor Web The Semantic Sensor Web (SSW) is a marriage of sensor web and semantic Web technologies. The encoding of sensor descriptions and sensor observation data with Semantic Web languages enables more expressive representation, advanced access, and formal ...
*
SensorML
SensorML is an approved Open Geospatial Consortium standar and an XML encoding for describing sensors and measurement processes. SensorML can be used to describe a wide range of sensors, including both dynamic and stationary platforms and both in- ...
External links
Observations and SamplingWiki page @ SEEGrid with examples from environmental sciences (no login required)
References
{{DEFAULTSORT:Observations And Measurements
Information science
Sensor networks
XML-based standards
Markup languages
Open Geospatial Consortium
ISO/TC 211
ISO standards
Geographic data and information