Coverage Content Information

A coverage is the distribution of a set of properties (or ranges) on a spatiotemporal domain. When the content type of the coverage is image, there is an implicit interdependency between the coverage properties. Typically, the color of an RGB image cell is the combination of the values of the red, green and blue properties. When the content type of the coverage is physical measurement or classifications, there is barely this kind of interdependency between the different properties even if each property contributes to the definition of the cell range. When the content type is mixed, there is no explicit interdependency but they may exist implicitly (a classification range can be combined with red, green, and blue ranges).

Special Cells may be used to:

* provide a meaning to a full cell sample, typically to define the red, green, and blue values of the "transparent" pixel of an RGB image, and more generally to the values of an interdependent set of properties.

• provide a meaning to values of a single range, typically when the content type of the coverage is not image.

In the first case, the record implementing the Special Cell Value shall provide a value for each of the interdependent range elements, e.g. a value for each of the red, green, and blue bands of an RGB image. There isn't necessarily a special cell defined for each of the coverage cells (i.e. for each combination of red, green, and blue in the image) since the intent is to provide a meaning to some specific cells.

In the second case, the Special Cell Value only provides a name, definition for a single value of only one of the range elements. Each record implementing a Special Cell Value provides a value for only one of the range elements. For a given range, there is either no special cells (because there is no predefined domain of value) typically when the range contains a measurement, or a special cell for each value of the range in order to fully document its domain of value.

In mixed coverage, the two types of special cells may occur depending on the interdependency of the ranges.

The properties of Coverage Content Information are listed below.

Identifier	Title / Description	Value Domain	Card
contentType [DMF/Data]	Content Type Type of information represented by the cell value.	Coverage Content Type Codelist	1
range [DMF/Data]	Range Information on the range of the cell measurement value.	Range	0..*
specialCell [DMF/Specific]	Special Cell Cell playing a specific role (e.g. no data or cloud) in the coverage. When the content type of the coverage is a thematic Classification, each thematic class is represented by a special cell.	Special Cell Values	0..*
imagingCondition [DMF/Sensor]	Imaging Condition Conditions affecting the image. Note: if multiple reasons for bad condition exist, use the worst case.	Imaging Condition Codelist	0..1

DMF/Core	DMF/Core defines the minimum set of metadata elements to be implemented by any metadata catalogue. This set satisfies the discovery use case.
DMF/Common	DMF/Common is an additional set of metadata elements for a more complete description of any type of resource supported by DMF. It extends DMF/Core and covers discovery and basic evaluation use cases.
DMF/Data	DMF/Data extends DMF/Common for data related resources (i.e. dataset, series and tile). DMF/Data adds metadata elements for evaluation and use.
DMF/Sensor	A DMF/Sensor class extending DMF/Data for sensors.
DMF/Specific	DMF/Specific is an extension of the ISO metadata standards for high level military implementation of the DMF metadata elements.