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.
Use of a common model for observation metadata allows data to be combined unambiguously, across discipline boundaries.
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[5]).
Specific sampling features, such as station, specimen, transect, section, are used in many application domains, and common processing and visualization tools are used.
[10][11] Version 2.0 of the Observations Data Model ("ODM2"),[12] developed by the Consortium of Universities for the Advancement of Hydrologic Science, Inc. (CUAHSI)[13] and the Critical Zone Observatory project, adapts O&M.