Dear List, thanks to Christpher Schmidt and some research the confusion is solved. So here I describe some usefull things to know about GeoRSS layers.
1) The GeoRSS format reverses X and Y positions. So the first number in a GeoRSS part like <gml:pos>6.36844646999779 51.8855430932258</gml:pos> should be the Y-coordinate (or latitude) the second number the X-coordinate (or longitude). 2) Although the GeoRSS format should be in EPSG:4326 by definition, in Openlayers it is possible to use other coordinate systems. E.g. A GML layer in EPSG:28992 lines up perfectly with a GeoRSS layer in EPSG:28992 without any reprojection. 3) It is possible to reproject GeoRSS layers by the familiar openlayers reprojection methods. Don't forget to include the proj4 library and a suitable definition for your coordinate system! Here is a working example: <script src="http://www.openlayers.org/api/OpenLayers.js";></script> <script src="js/proj4js/lib/proj4js-compressed.js" type="text/javascript"></script> <script type="text/javascript"> Proj4js.defs["EPSG:28992"] = "+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.999908 +x_0=155000 +y_0=463000 +ellps=bessel +towgs84=565.237,50.0087,465.658,-0.406857,0.350733,-1.87035,4.0812 +units=m +no_defs"; Proj4js.defs["EPSG:900913"] = "+proj=merc +a=6378137 +b=6378137 +lat_ts=0.0 +lon_0=0.0 +x_0=0.0 +y_0=0 +k=1.0 +units=m +nadgri...@null +no_defs"; Proj4js.defs["EPSG:4326"] = "+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs"; var map = null; var plangebiedLayerURL; var rsslayerURL; function init(){ map = new OpenLayers.Map('map', { allOverlays: true, maxExtent :new OpenLayers.Bounds(222222.273,432970.413,223085.973,433807.112), units :'m', projection: new OpenLayers.Projection("EPSG:28992"), displayProjection: new OpenLayers.Projection("EPSG:28992"), controls: [] }); plangebiedLayerURL = "wkt/NL.IMRO.0999.BP2008000001-0005.wkt"; plangebiedBaseLayer = new OpenLayers.Layer.GML("Plangebied", plangebiedLayerURL, { format: OpenLayers.Format.WKT, units :'m', projection :new OpenLayers.Projection("EPSG:28992"), }) plangebiedBaseLayer.setIsBaseLayer(true); map.addLayers([plangebiedBaseLayer]); rsslayerURL = "wkt/NL.IMRO.0999.BP2008000001-0005-2r.rss"; rssLayer = new OpenLayers.Layer.GeoRSS("Informatielaag",rsslayerURL, { projection: new OpenLayers.Projection("EPSG:4326"), }); map.addLayers([rssLayer]); map.zoomToMaxExtent(); map.addControl(new OpenLayers.Control.PanZoomBar()); map.addControl(new OpenLayers.Control.LayerSwitcher()); map.addControl(new OpenLayers.Control.MousePosition()); } </script> Thanks for all the help, MArco DeDuikertjes schreef: > Dear List, > > I have a georss file (with should be by definition in EPSG:4326) with > one point: > <gml:pos>6.36844646999779 51.8855430932258</gml:pos> it gets reprojected > without me asking for it. > > When I show that as simple as possible in openlayers with: > (working example on: > http://80.101.100.35/planhosting/testplannen/openlayers/showmap3c.html) > var map = null; > var rsslayerURL; > > function init(){ > > map = new OpenLayers.Map('map', { > allOverlays: true, > controls: [] > }); > > rsslayerURL = "wkt/NL.IMRO.0999.BP2008000001-0005-2b.rss"; > rssLayer = new > OpenLayers.Layer.GeoRSS("Informatielaag",rsslayerURL, { > > }); > > map.addLayers([rssLayer]); > map.zoomToMaxExtent(); > > map.addControl(new OpenLayers.Control.PanZoomBar()); > map.addControl(new OpenLayers.Control.LayerSwitcher()); > map.addControl(new OpenLayers.Control.MousePosition()); > > The point gets (according to the mouseposition) reprojected to about > 52.38 11.25. Why is that? I've never asked for that. > > If I specify EPSG:4326 as layerprojection, mapprojection and > displayprojection the same happens. > (working example: > http://80.101.100.35/planhosting/testplannen/openlayers/showmap3b.html). > > If I try to reproject it together with other data (Working example: > http://80.101.100.35/planhosting/testplannen/openlayers/showmap3.html), > the other data gets reprojected as should, but not the georss layer. > > What is happening ? > Please help, I'd like to have the georss layer lined up with my data in > epsg 28992. > > MArco > _______________________________________________ > Users mailing list > [email protected] > http://openlayers.org/mailman/listinfo/users > _______________________________________________ Users mailing list [email protected] http://openlayers.org/mailman/listinfo/users
