This specification defines <i>TimeseriesObservation</i> as a type of OM_Observation with particular requirements on the feature of interest, the result (must be a <i>Timeseries)</i>, the procedure, and other aspects of the observation.<br /></p><p><br /></p><p>Two subtypes of <i>TimeseriesObservation </i>offer two different encoding structures for the timeseries result: a time-value pair style structure where the time, value and associated metadata are encoded as coupled items (<i>TimeseriesTVPObservation</i>), and a separated structure where the time and values are represented as separate collections with metadata described separately to the time and values (<i>TimeseriesDomainRangeObservation</i>). The second approach will most often result in a more compact encoding due to a more efficient structuring and is consistent with the ISO 19123 Coverages model.<br /></p><p><br /></p><p>In this conceptual model TimeseriesTVPObservation and Timeseries are further sub-classed into: Categorical<i>TimeseriesTVPObservation, MeasurementTimeseriesTVPObservation,CategoricalTimeseriesDomainRangeObservation </i>and<i> MeasurementTimeseriesDomainRangeObservation.</i><br /></p><p><i><br /></p><p></i>It should be noted that the normative XML implementation takes a soft-typing approach to these classes and they are all implemented using OM_Observation<i>. </i>The subclass is specified by the om:type parameter.<br /></p>