Hi All, We've updated the MassGIS Lyceum example to include using a WMS as basemaps. http://lyceum.massgis.state.ma.us/wiki/doku.php?id=googlemapsv3:home
<http://lyceum.massgis.state.ma.us/wiki/doku.php?id=googlemapsv3:home>An example with the NOAA data can be found here: http://maps.massgis.state.ma.us/mhc/examples/gmap3wms_exampleNOAA.html <http://maps.massgis.state.ma.us/mhc/examples/gmap3wms_exampleNOAA.html>Using the NOAA data results in some strange problems with the overlays having white lines around tiles or pairs of tiles. I'll post asking about it in a separate thread, but if anyone has thoughts as to what could cause that/how to fix it, I'd love to hear them. Josh On Thu, May 27, 2010 at 10:46 AM, Davide Cremonesi <[email protected]>wrote: > Hello there, > I've put together a prototype implementation of such an ImageMapType > implementation. > If you want you can have a look here: > > http://neogismap.appspot.com/wms/index.html > > As you can see there are some problems with the projection, but this can > probably be fixed playing with the SRS parameter that you pass to the WMS > Server. > > I will try in the future to wrap it in a nice class with all the > "prototype" syntax and so on... stay tuned. > > Regards, > Davide > > > 2010/5/27 Josh Rosenthal <[email protected]> > >> Last time I asked about WMS, KakaduDreamer pointed me towards his >> http://earthalerts.manyjourneys.com/web/, which led to me throwing up an >> overlay example. Not base layers, but it might be helpful. >> http://lyceum.massgis.state.ma.us/wiki/doku.php?id=googlemapsv3:home >> >> As Davide mentioned, it takes advantage of the data being in a WMS, >> rerequesting @ different zoom levels, etc. Coordinate conversion is >> implemented in a Custom Projection which has methods fromLatLngToPoint, >> fromDivPixelToLatLng, >> and just to be sure, fromDivPixelToSphericalMercator All that said, this >> creates an overlay, not a replacement base layer. >> >> Esa has some examples with putting OpenStreetMap as a base layer here. (He >> also shows how you'd reconstruct existing base map types.) The syntax looks >> very similar for baseMaps and Overlays, so you could probably use similar >> logic to my WMS example. >> http://koti.mbnet.fi/ojalesa/v3/osm_dual.htm >> >> Hopefully thats of some help. >> >> Josh >> >> >> >> >> >> On Thu, May 27, 2010 at 7:09 AM, Davide Cremonesi <[email protected]>wrote: >> >>> Hello everybody, >>> I must say that I don't like this solution based on GroundOverlays (of >>> course you might well be happy with it and ignore my message :-). >>> The problem I see is that once you get the image at the largest scale it >>> gets scaled by the client at lower scales (zooming in) and resolution get >>> worst and worst. The advantage of a WMS service is that images are created >>> on the server at different scales and extents modifying the BBOX parameter >>> in the URL. >>> What you need to do is convert Google tile x, y, and zoom into a suitable >>> WMS URL. >>> >>> Here is a good starting point (based on v2 API): >>> http://blog.kylemulka.com/2005/08/wms-in-google-maps/ >>> >>> Cheers, >>> Davide >>> >>> PS if I have some time I will try to make an implementation myself and >>> make it pulbic here on the forum >>> >>> 2010/5/27 Jack Berberette <[email protected]> >>> >>> Wow...thanks for all of your effort in this William! I'll definitely >>>> work on this when I get back to the office tomorrow. You've really gone >>>> above and beyond for us and we truly appreciate it. >>>> >>>> Thanks, >>>> >>>> Jack >>>> >>>> >>>> On Wed, May 26, 2010 at 10:30 PM, William <[email protected]>wrote: >>>> >>>>> On May 27, 6:03 am, Jack Berberette <[email protected]> wrote: >>>>> > >>>>> > is it posible to tile the imagery so not matter what area you >>>>> > wanted to look at you could see the cloud cover? >>>>> > >>>>> >>>>> the help file says you can select Google Mercator map projection (EPSG: >>>>> 900913), but I only got blank images when I tried that option. >>>>> >>>>> Since the JPG files are small, it might be ok to use the Ground >>>>> Overlay with a 50% extended border around the image, and then update >>>>> the image whenever the zoom changes or the user pans outside this >>>>> area. >>>>> >>>>> http://nowcoast.noaa.gov/help/mapservices.shtml?name=mapservices >>>>> >>>>> WMS Map Projections & Spatial Reference Systems (SRS) >>>>> The WMS standard requires that every request must include the "SRS" >>>>> parameter, which specifies the identifier of the desired Spatial >>>>> Reference System (projection) of the requested map image. In addition >>>>> to the standard geographic projections, nowCOAST map services allow >>>>> requests to be made in the Web Mercator projection, which is used by >>>>> many popular online mapping services such as Microsoft Bing and Google >>>>> Maps. When overlaying nowCOAST data with Google Maps or Microsoft Bing >>>>> imagery, it is recommended to use either the "EPSG:102113" or "EPSG: >>>>> 900913" SRS values in your requests. Otherwise, the most commonly used >>>>> projections are NAD83 and WGS84. >>>>> >>>>> SRS values can be specified in a WMS request by including >>>>> "&SRS=IDENTIFIER" in the target WMS URL, where "IDENTIFIER" is >>>>> replaced with one of the supported SRS Identifier values, listed >>>>> below: >>>>> EPSG:4267 North American Datum of 1927 (NAD 27) >>>>> EPSG:4269 North American Datum of 1983 (NAD 83) >>>>> EPSG:4326 World Geodetic System 1984 (WGS 84) >>>>> EPSG:102113 Web Mercator (ESRI Identifier) >>>>> EPSG:900913 Web Mercator (Google Identifier) >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Google Maps JavaScript API v3" group. >>>>> To post to this group, send email to >>>>> [email protected]. >>>>> To unsubscribe from this group, send email to >>>>> [email protected]<google-maps-js-api-v3%[email protected]> >>>>> . >>>>> For more options, visit this group at >>>>> http://groups.google.com/group/google-maps-js-api-v3?hl=en. >>>>> >>>>> >>>> -- >>>> You received this message because you are subscribed to the Google >>>> Groups "Google Maps JavaScript API v3" group. >>>> To post to this group, send email to >>>> [email protected]. >>>> To unsubscribe from this group, send email to >>>> [email protected]<google-maps-js-api-v3%[email protected]> >>>> . >>>> For more options, visit this group at >>>> http://groups.google.com/group/google-maps-js-api-v3?hl=en. >>>> >>> >>> -- >>> You received this message because you are subscribed to the Google Groups >>> "Google Maps JavaScript API v3" group. >>> To post to this group, send email to >>> [email protected]. >>> To unsubscribe from this group, send email to >>> [email protected]<google-maps-js-api-v3%[email protected]> >>> . >>> For more options, visit this group at >>> http://groups.google.com/group/google-maps-js-api-v3?hl=en. >>> >> >> -- >> You received this message because you are subscribed to the Google Groups >> "Google Maps JavaScript API v3" group. >> To post to this group, send email to >> [email protected]. >> To unsubscribe from this group, send email to >> [email protected]<google-maps-js-api-v3%[email protected]> >> . >> For more options, visit this group at >> http://groups.google.com/group/google-maps-js-api-v3?hl=en. >> > > -- > You received this message because you are subscribed to the Google Groups > "Google Maps JavaScript API v3" group. > To post to this group, send email to > [email protected]. > To unsubscribe from this group, send email to > [email protected]<google-maps-js-api-v3%[email protected]> > . > For more options, visit this group at > http://groups.google.com/group/google-maps-js-api-v3?hl=en. > -- You received this message because you are subscribed to the Google Groups "Google Maps JavaScript API v3" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/google-maps-js-api-v3?hl=en.
