Geospatial test pages

About the geo labs pages

A collection of test pages related to geospatial calls and user interfaces.

  • Currently testing converting GEBCO data to KML (GEBCO KML) to test associating data from several different groups with.
  • Testing a javascript based GIS client (see "GIS" link to the right) to evaluate the ability to do such user interfaces from the browser.

Spatial Calls

Spatial RDF Calls

At present geospatial RDF calls are still in the development stage. The Virtuoso sever we presently use exposes the current suggestions for implementing geospatial calls in SPARQL. Should this change Virtuoso will update their implementation.

Refs:

# Simple geo-spatial SPARQL call
PREFIX  geo:  <http://www.w3.org/2003/01/geo/wgs84_pos#>  
SELECT  ?m ?geo
FROM <http://chronos.org/janusamp#>
WHERE  
{ 
	      ?m  geo:geometry  ?geo    . 
          FILTER ( <bif:st_intersects> ( ?geo, <bif:st_point> (0, 52), 1000))
}                         
                    

Spatial Fusion Calls

Google's Fusion tables (Ref: http://www.google.com/fusiontables) also allow for geospatial calls. The approach is very SQL like and uses simple REST calls. Both CIRCLE and RECTANGLE shapes are supported.

#!/bin/bash
 function FusionTableQuery() {
  local sql=$1
  curl -L -s -d sql="$sql" https://www.google.com/fusiontables/api/query
}
# Example geospatial call to fusion table
FusionTableQuery "SELECT * FROM 402018 WHERE ST_INTERSECTS(GeoLoc, CIRCLE(LATLNG(-76.7, -175.1), 20000))"                       
                    

Screencast review of geo SPARQL and Google Fusion table calls