FAQ - WeatherSentry® Web Feature Service (WFS)

Version 6


    What libraries can I use to access the service?

    In general, any library supporting OGC Web Feature Service version 1.1.0 should work with the service. Also note that the HTTP requests must follow HTTP Basic, HTTP Digest, or OAuth1 authentication standards. If your library doesn't have built in support for this you may need to create a proxy.

     

     

    What versions of OGC WFS do you support?

    This product supports WFS version 1.0.0 and 1.1.0. Note that version 1.0.0 and 1.1.0 capability documents are different and filters operators that work in version 1.0.0, may not work in version 1.1.0, and vice versa.

     

     

    When should I use BBOX in GetFeature requests?

    BBOX is a convenient way to bound GetFeature requests by location without using a FILTER. If fact, BBOX can not be used with a FILTER.

     

     

    When should I use FILTER in GetFeature requests?

    The FILTER parameter should be used to find features of interest based on time, location or other available attributes identified in the response to a DescribeFeatureType request.  Putting a FILTER on a request also reduces response payload & wait time.

     

     

    Are there any restrictions on the number of features I can request?

    Yes, the maximum number of features returned by any GetFeature request is 10,000. Use the STARTINDEX parameter in subsequent GetFeature requests to acquire additional features. For example, if the first request of a feature type returns 10,000 features, make a second request with STARTINDEX=10001 to get the next 10,000 features.

     

     

    Can I request features in a coordinate system other than EPSG:4326?

    In WFS version 1.0.0, there is no mechanism to specify an SRS in GetFeature requests for returned feature geometries; features are returned in the coordinate system advertised in the capabilities document, which for this product is EPSG:4326.

     

    In WFS version 1.1.0, use the SRSNAME parameter in GetFeature requests to specify a coordinate system to be used for returned feature geometries.

     

    For example:

    http://weather-services.telventdtn.com/digest/wfs_v1/wfs.wsgi?VERSION=1.0.0&SERVICE=WFS&REQUEST=GetFeature&TYPENAME=CURRENT_OBSERVATIONS&BBOX=-93.5,44.7,-93.1,45.1,EPSG:4326&SRSNAME=EPSG:3857&EXCEPTIONS=XML&MAXFEATURES=1

     

     

    How do I get features for a specific observing site?

    Use a FILTER parameter to specify a known stationid or location.

     

    For example, to see the latest observation from the Minneapolis-St. Paul International Airport (KMSP):