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<TITLE>Problems Mixing WMS, Google, and Vector Layers</TITLE>
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<P><FONT SIZE=2 FACE="Arial">I'm working on an application that uses either WMS or Google as a base layer, with Vector and Marker layer overlays. My application draws markers on the Marker layer, then draws a Vector layer with points at the same exact locations as the markers but connected by lines.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">I noticed some odd behavior when I switch base maps using the LayerSwitcher control. It seems as though Google Maps uses a different aspect ratio for its tiles than the WMS implementation - toggling between the two layers shows that the features on the tiles in the Google layer do not precisely line up with the features on the tiles in the WMS layer (Google tiles seem "narrower" than the WMS ones). Since these two layers are never seen at the same time, this is generally not a problem.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">What is a problem is this: when I switch from WMS to Google, the markers appear above the identical feature regardless of the base map. Because the aspect ratio changes, switching layers without panning the map causes the markers to appear to "jump" from one spot on the screen to another as the base map changes. This is exactly the behavior I expect. However, the points of the lines drawn on the Vector layer do not shift along with the markers on the Marker layer - the Vector layer features remain fixed on the screen.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">The difference between the Vector layer points and Marker layer markers seems to be in vertical position (latitude) only - the lines appear either too high or too low on the Google map relative to the markers. Horizontal position (longitude) seems to be correct.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">The upshot is that the lines are in the correct positions when WMS is the base layer, but they are in the wrong positions (not connected to the markers) when Google is used as the base. Panning the map causes the markers to remain in the correct positions regardless of base map. But the vector features float around as the map is panned, not staying in fixed positions relative to the features on the tiles.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Has anyone else noticed this behavior? Am I doing something wrong? Any ideas for a fix?</FONT>
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<P><FONT SIZE=2 FACE="Arial">-eP</FONT>
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