Elevation Service Specification

Gross Specification

Feature	Status
Works through Apache.	Done
Uses HTTP GET from an endpoint.	Done
If /proc/loadavg > 5 then return 503 Service Unavailable.	Not Done
HTTP cache headers are based on the latest date of the data sources.	Not Done

Data Sources

Source	Currently Included
SRTM	Yes
Nova Scotia DEM	No
NYC DEM	No
Canadian Elevation Data API	No

Request Parameters

Name	Description	Example	Status
bbox	minlong,minlat,maxlong,maxlat	bbox=4.06,50.86,5.13,51.33	Done
format	```rdf/xml	n3	ntriples
scale	Distance between points in metres.	scale=90	Done

Note: format arguments are either format=rdf/xml|n3|xyz|png or controlled through an HTTP Accept header. Any error on this parameter is reported as 406 Not Acceptable.

Provenance Information

RDF Provenance information has to be created for each data source.

Status: Not Done

Example:

<prov:Collection rdf:resource="http://localhost/answer/xx">
  <rdf:type rdf:resource="void:Dataset"/>
  <prov:wasGeneratedBy>
    <prov:SoftwareAgent rdf:about="http://localhost/api/xx" >
      <prov:wasGeneratedBy rdf:about="http://localhost/api/about" />
      <rdfs:label xml:lang="en">Elevation Server API process ID xxxxx</rdfs:label>
      <prov:startedAtTime>2014-07-14T01:01:01Z</prov:startedAtTime>
      <prov:endedAtTime>2014-07-14T01:01:03Z</prov:endedAtTime>
      <prov:wasInformedBy rdf:resource="http://localhost/api/datasets/A"/>
      <prov:wasInformedBy rdf:resource="http://localhost/api/datasets/B"/>
      <prov:wasInformedBy rdf:resource="http://localhost/api/datasets/C"/>
    </prov:SoftwareAgent>
  </prov:wasGeneratedBy>
  <prov:hadMember>
    <!-- This point extracted from another dataset. -->
    <geo:Point rdf:resource="http://localhost/answer/point/xx">
      <geo:long>....</geo:long>
      <geo:lat>....</geo:lat>
      <prov:wasInformedBy rdf:resource="http://localhost/api/datasets/A"/>
    </geo:Point>
  </prov:hadMember>
  <prov:hadMember>
    <!-- This point extracted inferred by an algorithm and another dataset. -->
    <geo:Point rdf:resource="http://localhost/answer/point/xx">
      <geo:long>....</geo:long>
      <geo:lat>....</geo:lat>
      <prov:wasGeneratedBy rdf:resource="http://localhost/api/xx"/>
      <prov:wasInformedBy rdf:resource="http://localhost/api/datasets/B"/>
    </geo:Point>
  </prov:hadMember>
  ...
</prov:Collection>

Permanent Metadata

Permanent metadata hangs off the endpoint as a static document at http://.../endpoint/about.

Status: Not done

Example:

<prov:Activity rdf:about="http://localhost/api/about">
  <rdfs:label xml:lang="en">Elevation Server API Process</rdfs:label>
  <rdf:type rdf:resource="http://www.w3.org/ns/prov#Activity"/>
  <rdf:type rdf:resource="http://purl.oclc.org/NET/ssnx/ssn#Process"/>
  <prov:wasAssociatedWith rdf:resource="http://rdf.muninn-project.org/ww1/2011/11/11/Organization/Muninn"/>
  <foaf:name xml:lang="en">Elevation Server API Process</foaf:name>
  <doap:Version>2.0</doap:Version>
  <rdf:type rdf:resource="http://www.w3.org/ns/prov#SoftwareAgent"/>
  <rdf:type rdf:resource="http://usefulinc.com/ns/doap#Project"/>
  <doap:service-endpoint rdf:resource="http://localhost/api"/>
  <doap:developer rdf:resource="http://localhost/markfarrell"/>
  <doap:homepage rdf:resource="http://localhost/"/>
  <doap:blog rdf:resource="http://blog.muninn-project.org/"/>
  <doap:description xml:lang="en">The Elevation Server API will ...</doap:description>
  <cc:attributionName xml:lang="en">The Muninn Project</cc:attributionName>
  <cc:attributionURL rdf:resource="http://www.muninn-project.org/"/>
</prov:Activity>