Observations may be associated with a geospatial location. The primary location of
interest is usually associated with the ultimate feature-of-interest, so this is a principle
classifier of an observation and its result, used in indexing and discovery.
However, the location may not be trivially available. For example: in remote sensing
applications, a complex processing chain is required to geolocate the scene or swath; in
feature-detection applications the initial observation may be made on a scene, but the
detected entity, which is the ultimate feature of interest, occupies some location within it.
The distinction between the proximate and ultimate feature of interest is a key
consideration in these cases (see sub-clauses 6.3.1 and O&M-Part 2).