Most of the observations used to characterize and understand our environment are made using instruments that have specific characteristics. These instruments and characteristics can change over time so it is important to document them in order to avoid misunderstanding. Generally the required content is a set of instrument attributes with definitions, units and values.
- citation: This is a reference to a document or a web page that describes some aspect of the instrument. Any number of these references can be included and the referenced documents can be in any format. Note that these citations include unique identifiers for the citations.
- identifier: This is an identifier for the instrument. It includes a code and an authority or source for that code. At present the standard allows only one of these for each instrument. We are hoping to relax this limitation in the revision of the standard.
- type: This is a character string that gives the type of the instrument. Selecting this string from a controlled vocabulary is helpful for consistent searching. One example of such a controlled vocabulary is the NASA Global Change Master Directory Instrument Keyword list. An instrument can have only one type.
- description: This is a brief paragraph describing the instrument suitable for use on a web page.
- mountedOn: This gives the MI_Platform that the instrument is mounted on. This would typically be done using a reference to a MI_Platform included in the same metadata record.