Compute Surface of Geometries

Compute the surface of WKT geometries in square meters. Stores the result in a novel column of type Double.

In order to compute the size of the area in square meters, the node reprojects on the fly the geometries into an automatic projection [1] as defined by the Open Geospatial Consortium [2]. This might lead to conversion errors in case your initial Coordinate Reference System is not an ESPG standard one. If you get errors related to Bursa Wolf parameters or similar errors due to projection, please try to use the "Reproject WKT geometries" in order to first reproject your geometries into a welldefined CRS.

The actual computation is done by the powerful Geotools library .

• [1] Web Mapping Testbed, "WM Automatic Projections", http://www.digitalearth.gov/wmt/auto.html
• [2] Open Geospatial Consortium, Inc. (2000) "OpenGIS® Web Map Server Interface Implementation Specification", OpenGIS Project Document 00-028, url

Input ports

1. Type: Table
   spatial population
   A table with spatial data

Output ports

1. Type: Table
   spatial population
   The table with an additional column containing the surface