Presentation at Postgraduate Research Conference 17-19 March 2008.

1. Using geobrowsers for thematic mapping Bjørn Sandvik MSc in Geographical Information Science University of Edinburgh Postgraduate Research Conference 17-19 March 2008 Supervisors: Bruce Gittings and James Reid

6. Thematic Mapping Engine Thematic Mapping Parameters OpenLayers PHP Library Web Interface Web Processing Service Thematic Mapping Engine

7. Choropleth map in Google Earth $map = new ThematicMap(); $map->setType("choropleth"); $map->addData($values); $map->addBorders($borders); $map->setColourRange($colors); $kml = $map->getKML(); Data source: UNdata

8. Using the 3rd dimension $kml = $map->getKML(‘3D’); Data source: UNdata

9. Proportional symbol maps $map->setType(“symbol"); $map->setBasenam($basemap); $map->setSymbolSize(”pop”); Data source: UNdata and Tom Patterson

10. Challenge 1: polygon holes Data source: UNdata

11. Challenge 2: Mercator Can OpenLayers do better?

12. Challenge 3: Performance

13. Challenge 4: Complexity function kmlSymbolCalculator( $longitude, $latitude, $distance, $points, $altitude ) { $EARTH_RADIUS_EQUATOR = 6378140.0; $RADIAN = 180 / pi(); $long = $longitude; $lat = $latitude; $long = $long / $RADIAN; $lat = $lat / $RADIAN; $f = 1/298.257; $e = 0.08181922; $kml = '<Polygon>' . PHP_EOL . ' <outerBoundaryIs>' . PHP_EOL . ' <LinearRing>' . PHP_EOL . ' <coordinates>'; for ( $bearing = 0; $bearing <= 360; $bearing += 360/$points) { $b = $bearing / $RADIAN; $R = $EARTH_RADIUS_EQUATOR * (1 - $e * $e) / pow( (1 - $e*$e * pow(sin($lat),2)), 1.5); $psi = $distance/$R; $phi = pi()/2 - $lat; $arccos = cos($psi) * cos($phi) + sin($psi) * sin($phi) * cos($b); $latA = (pi()/2 - acos($arccos)) * $RADIAN; $arcsin = sin($b) * sin($psi) / sin($phi); $longA = ($long - asin($arcsin)) * $RADIAN; $kml .= &quot; &quot;.$longA.&quot;,&quot;.$latA; } $kml .= ' </coordinates>' . PHP_EOL . ' </LinearRing>' . PHP_EOL . ' </outerBoundaryIs>' . PHP_EOL; return $kml; }

14. Challenge 5: Temporality

15. Best to follow standards? Thematic Mapping Engine DDI/DCMI SDMX Metadata ISO 19115:2003 OGC SLD/SE extension? Best practices Thematic mapping techniques GML / WFS WKT / WKB GeoJSON XML CSV Array JSON TMS Parameters Storage Data in Data out Geobrowser WMS Map Tiles KML WFS / GML GeoJSON GeoRSS

19. Website and blog thematicmapping.org