[OpenLayers-Users] Distance problem

[Nicolas Noe]

Hi everyone,

I have a simple problem, bit I can't figure it. I'm probably missing 
something very simple and stupid !

I have an OL map with google background. The projection is EPSG:900913, 
so the map unit is meters (right?).
I have a marker layer, on which I add a first marker. Then I ask OL to 
compute a second marker 1 kilometer on the east, and display it.

It seems to work, except of my distance problem : if I check with the OL 
scaleline, there's 1 KM between both markers (which is correct). 
However, if I use the ruler tool of Google Earth, I can see there is 
only about 650 meters between these 2 points.

Do you have any idea of where my error is ?
Thanks in advance,

Here is my code :

var BeBounds = new OpenLayers.Bounds(2.5, 49.5, 6.5, 51.5);

function mapInit() {
 
  var map = new OpenLayers.Map('map', {
        projection: new OpenLayers.Projection("EPSG:900913"),
        controls: [
                        new OpenLayers.Control.Navigation(),
                        new OpenLayers.Control.PanZoomBar(),
                        new 
OpenLayers.Control.LayerSwitcher({'ascending':false}),
                        new OpenLayers.Control.Permalink(),
                        new OpenLayers.Control.ScaleLine(),
                        new OpenLayers.Control.Permalink('permalink'),
                        new OpenLayers.Control.MousePosition(),
                        new OpenLayers.Control.OverviewMap(),
                        new OpenLayers.Control.KeyboardDefaults()
                    ]
        });

   var gsat = new OpenLayers.Layer.Google("Google Hybrid",
        {
          type: G_HYBRID_MAP,
          'sphericalMercator':true,
          maxExtent: new 
OpenLayers.Bounds(-20037508.34,-20037508.34,20037508.34,20037508.34)
          /*, numZoomLevels: 20*/ });

  var markers = new OpenLayers.Layer.Markers("Markers");

  map.addLayer(gsat);
  map.addLayer(markers);
 
  // Add a marker
  var myPoint = new OpenLayers.LonLat(5.080646954,50.49373471);
  var myPointInMeters = myPoint.transform(new 
OpenLayers.Projection("EPSG:4326"), map.projection);

  var pt2 = myPointInMeters.add(1000,0);

  var mymark  = new OpenLayers.Marker(myPointInMeters);
  var mymark2 = new OpenLayers.Marker(pt2);
 
  markers.addMarker(mymark);
  markers.addMarker(mymark2);

  map.zoomToExtent(BeBounds.transform(new 
OpenLayers.Projection("EPSG:4326"), map.projection));
}