Friday, June 21, 2013

which OGC standard to use to recieve info from mobile phones being used as sensors

We're cooperating in an european FP7 project called COBWEB (http://cobwebproject.eu) on enabling citizens to contribute nature observations in biospheres. From an interoperability aspect it's quite usefull to use an OGC standard to publish observations from the registered phones. But which one to use, there's a couple of them out there. I did some research, but I'm still not sure. Maybe this research helps others, or comment if you have additional ideas on the matter


Most prominent is the openLS standard, which is actually a set of "core" services around location. One of them being the location service, where a client registers with a server and the server sends out requests for postion at regular intervals, the client then responses with it's location. I'm not sure though, if such a model would work on mobile phones. I think a phone can't have a listener for incoming requests like this (what if it's stand-by or offline at that moment)? You can probably run some webserver like i-jetty or nanohttpd, but i guess it will drain the battery if you keep it alive constantly.

GeoSMS offers location info over SMS, which is a rather costly method, but could work out on phones without internet access.  

NetCDF is a set of formats for creation, access, and sharing of array-oriented data. NetCDF is quite optimal in size and can be accessed with the thredds data server using OGC:CSW or OpeNDap. Seems not very optimal for single sensor transactions. Quite strong in aggregations. NetCDF is mainly used in oceanography and meteorology sensing  

SensorWeb  
SOS/O&M: standards for querying and inserting sensor observations and registring sensors (might be usefull for mobile use, although seems to follow same path as OpenLS in that the server takes initiative to read the sensor, and i'm not sure if this is possible on a mobile phone)  
SES (event service): register for certain events, and get notified if event occurs (might be needed in some usecases)  
 SPS (planing service): can be used to query if a sensor is capable of performing a task and assign the actual task (usecase: send a message to all registered phones: "who is in neighboorhood of xxx,yyy", if yes: "please go to xxx,yyy") 

Geopackage is mostly a database for use on a mobile phone in case of lack of network connectivity. Users can store their measurements in the local database and when back online use the data from the database to trigger posting of observations. Also users might cache image- or vector-tiles for an area so they still have a map while being offline. Geopackage offers some nice options over using plain file or sqlite storage, but comes at a price (extra dependencies for the app).  

WFS-transactional can be used to upload measurements in GML format  

WPS can be used to do any other request/response type even asynchronous, can be used to upload measurements

Conclusion:
  • Most suitable would be SOS or OpenLS, but i wonder if they'd fit in a usecase where a phone takes initiative to send observations as soon as it's back online.
  • If above doesn't work out WFS-t or WPS seem most appropriate
enable citizens living within Biosphere Reserves to collect environmental data using mobile devices - See more at: http://cobwebproject.eu/#sthash.tBOqUwad.dpuf
enable citizens living within Biosphere Reserves to collect environmental data using mobile devices - See more at: http://cobwebproject.eu/#sthash.tBOqUwad.dpuf
enable citizens living within Biosphere Reserves to collect environmental data using mobile devices - See more at: http://cobwebproject.eu/#sthash.tBOqUwad.dpuf
enable citizens living within Biosphere Reserves to collect environmental data using mobile devices - See more at: http://cobwebproject.eu/#sthash.tBOqUwad.dpuf
enable citizens living within Biosphere Reserves to collect environmental data using mobile devices - See more at: http://cobwebproject.eu/#sthash.tBOqUwad.dpuf

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