Specialized observation metadata classes for OGC WaterML2.0 OGC WaterML 2.0 is an OGC Standard. Copyright (c) 2012,2014 Open Geospatial Consortium. To obtain additional rights of use, visit http://www.opengeospatial.org/legal/ . Metadata relating to water observation. Specialisation of the ISO19115 MD_Metadata type. Defines the expected interval in which observations can be expected. e.g. daily. Indicates the statues of the observation. E.g. unreleased, verified etc. Indicates the medium that was sampled. E.g. water, air, etc. Defines the allowed gap between series when joining this time series with another. A soft-typed parameter to allow extension through name-value pairs.