All, We have been developing a web mapping application using google maps as the front end interface with a postgis backend. Using this application the user can draw a bounding box in google maps and the coordinates are then passed to postgis. With postgis we then perform a query on the polygons stored in the postgis database to return the area using ST_Intersection, ST_Transform (usually to UTM) and finally ST_Area. The application works great but the problem is that since we are trying to work on a global scale it is difficult to determine what projection (EPSG) to transform the data to calculate an accurate area since our data is in EPSG:4326 and returns decimal degrees. We can easily transform the query results to a UTM or a Albers projection however the results can be inaccurate since the user may select multiple zones or hemispheres when view the map at a global scale. Is there a accurate global projection for calculating area?
-- Travis K. Toronto, Canada ------------------------------------------------------------ "She knows there's no success like failure And that failure's no success at all." -Bob Dylan- ------------------------------------------------------------ _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
