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 (that is, descriptions of phenomena for which location is relevant), combined with software tools for managing, analyzing, and visualizing those data. In a ...

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 ca ...

. O&M is one of the core standards in the OGC Sensor Web Enablement suite, providing the response model for Sensor Observation Service (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 A general officer is an officer of high rank in the armies, and in some nations' air forces, space forces, and marines or naval infantry. In some usages the term "general officer" refers to a rank above colonel."general, adj. and n.". OED On ...

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

, 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 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

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 se ...

encoding is provided for transfer of data:
JSON Schema
An explicit OWL representation of O&M is available:
Observation schema (OWL2)

Sampling features (OWL2)
Th
W3C Semantic Sensor Network Ontology
provides an updated OWL 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

External links

Observations and Sampling
Wiki 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

Observation schema

Sampling features

Implementations

Related documents

See also

External links

References