Feature of Interest

Introduction

A Feature is generally defined in ISO 19109 and ISO 19101 as a thing that carries characteristics, or in other words that has properties. A property is always related to one feature. Feature is a component of an observation. In SOS a feature is the feature of interest of the observation. However, this definition is still too broad. The following possible explanations of feature could be depicted:

Possible types of Feature of Interest

•   An earth realm: For example, ocean, river, sea surface, body of water.

• Pros: It is similar to a feature of interest. It will always hold that the properties are related to this feature.
• Cons: Need category of earth realms. Difficult to get the smallest encompassing realm

• Medium: For example, air and water.

• Pros: Easy
• Cons: Too general. If dealing with earth observations more detailed information could be provided, as stated in 1.

• Location

• Pros: Information is available by the service
• Cons: This information is already provided in the observation response, either as a point or bounding box. This could be seen as the shape of the observation, as well (see 7).

• An event: For example, Hurricane Katrina

• Pros: Directly expresses the event of interest.
• Cons: Is not the feature being measured, but a process occurring in the proximity of a featureOfInterst.
• A system: For example, platform in a fixed position in the ocean
• Pros: Easy to understand
•  Cons: A platform doesn’t have the properties being measured, so it conflicts with the model. A platform is not the feature of interest.
• A named region: Monterey Bay, Golf of Mexico
• Pros: Would allow direct querying for regions of interest by name, if needed.
• Cons: This information could be inferred by a gazetteer service that could resolve locations for geographic names. Difficult to get the name for the minimum area covered.
• Shape made by the procedure: Curve (or  track) of a glider.  This is similar to what O&M part 2 (OGC 07-002r3) discusses about the strategy suitable for estimating the observed property via the observation procedure.
• Pros: Helps distinguishing the ultimate feature of interest with the procedure of an observation, when the procedure is confused with the feature of interest (e.g. a station).
• Cons: Adds another level of complexity.  In addition, this information could be described as a process, i.e. SensorML.

Best Practice: The Oceans IE team decided to use “earth realm” concepts as the featureOfInterest, until more precise guidance is available. Earth Realm, or any subcategory of it, is a feature of interest and so will not conflict with the O&M model.

URIs the Feature of Interest

Revision History

TODOs