Re: Addition of new use case: Creation of “virtual observations” from “analysis” phase of weather prediction model

Thanks Kerry. I see from your ref that ssn:Sensor _does_ include “computational methods”. When I looked at SSN it was the sensor-stimulus-observation model that I felt was incompatible with virtual observations … but glad that this use case is now in the mix for our future work. Jeremy

> On 23 Mar 2015, at 12:09, <Kerry.Taylor@csiro.au> <Kerry.Taylor@csiro.au> wrote:
> 
> Thanks Jeremy, for a use case that was missing!
>  
> Note that a “sensor” in SSN was always intended to include virtual sensors, and >=1  people have implemented this.
>  
> Extract from  SSN where “ssn:sensor” is defined (and see also the ”ssn:implements” property):
> A sensor can do (implements) sensing: that is, a sensor is any entity that can follow a sensing method and thus observe some Property of a FeatureOfInterest. Sensors may be physical devices, computational methods, a laboratory setup with a person following a method, or any other thing that can follow a Sensing Method to observe a Property.
> URI:
> http://purl.oclc.org/NET/ssnx/ssn#Sensor <http://purl.oclc.org/NET/ssnx/ssn#Sensor>
> Label:
> Sensor
> Source:
> skos:exactMatch 'sensor' [SensorML OGC-0700 <http://www.opengeospatial.org/standards/sensorml>] skos:closeMatch 'observation procedure' [O&M <http://www.opengeospatial.org/standards/om>] O&M allows sensors, methods, instruments, systems, algorithms and process chains as the processUsed of an observation; this ontology allows a similar range of things (any thing that can do sensing), just they are all grouped under the term sensor (which is thus wider than the O&M concept).
>  
> Kerry
>  
> From: Jeremy Tandy [mailto:jeremy.tandy@gmail.com <mailto:jeremy.tandy@gmail.com>] 
> Sent: Monday, 23 March 2015 10:33 PM
> To: SDW WG Public List
> Subject: Addition of new use case: Creation of “virtual observations” from “analysis” phase of weather prediction model
>  
> All - I have added another use case primarily of interest to SSN: [Creation of “virtual observations” from “analysis” phase of weather prediction model][1]. It revolves around the use of numerical simulations to create “virtual observations” rather than the “sensor-stimulus-observation” model which is at the heart of SSN.
>  
> I include the text of the Use Case below for reference:
> —
> National Meteorological Services (NMS), such as Met Office <http://www.metoffice.gov.uk/>, maintain a network of weather observation sites within their region of responsibility in order, amongst other things, to provide input to their numerical weather prediction models. The cost of maintaining these weather observation sites means that their number is limited. 
> Within the UK, and likely in other places too, there is a high demand for weather observations for specific locations. To meet this demand, the Met Office provides data for many more locations than the number of weather observation sites they maintain. In order to do this, “virtual observations” for these locations are derived from the “analysis” of the numerical weather prediction model. (“Analysis” is the term used to describe the initial state of the numerically modelled atmosphere from which the forecast is calculated; it incorporates real observations and provides a dynamically balanced representation of the atmosphere at a snapshot in time.)
> The metadata needed to provide context to a “virtual observation" is identical to that for normal observations; albeit that the procedure used to create the observation involves a computational simulation rather than a physical sensor and stimulus. Clearly, it is important to provide information about the procedure used to create the observation so that “real” observations can be distinguished from “virtual” observations.
> The Observations and Measurements (O&M, ISO 19156) is sufficiently flexible enough to accommodate use of a computational simulation for the observation procedure. However, the Semantic Sensor Network model is (appears to be?) rooted in the “sensor-stimulus-observation” model and, as such, does not seem to be applicable to cases such as “virtual observations”.
> —
>  
> Jeremy
>  
> [1]: https://www.w3.org/2015/spatial/wiki/Working_Use_Cases#Creation_of_.E2.80.9Cvirtual_observations.E2.80.9D_from_.E2.80.9Canalysis.E2.80.9D_phase_of_weather_prediction_model_.28primarily_SSN.3B_also_Best_Practice_.26_Time_.29 <https://www.w3.org/2015/spatial/wiki/Working_Use_Cases#Creation_of_.E2.80.9Cvirtual_observations.E2.80.9D_from_.E2.80.9Canalysis.E2.80.9D_phase_of_weather_prediction_model_.28primarily_SSN.3B_also_Best_Practice_.26_Time_.29>