topic Convert GPS coordinates to custom wkid in ArcGIS JavaScript Maps SDK Questions

Convert GPS coordinates to custom wkid

OscarMonell — Tue, 06 Mar 2012 12:30:45 GMT

We are trying to use GPS location in a map with services in wkid 3008 using this code:

     if (navigator.geolocation){          navigator.geolocation.getCurrentPosition(zoomToLocation, locationError);           }

    function zoomToLocation(location) {         var pt = new esri.geometry.Point(location.coords.longitude, location.coords.latitude);                   var outSR = new esri.SpatialReference({ wkid: 3008});        gsvc.project([ pt ], outSR, function(projectedPoints) {         pt = projectedPoints[0];         map.centerAndZoom(pt, 8);        }); }

But we don't get the expected result, map loads fine but when using position maps zooms in to a out of bounds location.
What are we missing?

Re: Convert GPS coordinates to custom wkid

HemingZhu — Tue, 06 Mar 2012 20:36:30 GMT

We are trying to use GPS location in a map with services in wkid 3008 using this code:

     if (navigator.geolocation){          navigator.geolocation.getCurrentPosition(zoomToLocation, locationError);           }

    function zoomToLocation(location) {         var pt = new esri.geometry.Point(location.coords.longitude, location.coords.latitude);                   var outSR = new esri.SpatialReference({ wkid: 3008});        gsvc.project([ pt ], outSR, function(projectedPoints) {         pt = projectedPoints[0];         map.centerAndZoom(pt, 8);        }); }

But we don't get the expected result, map loads fine but when using position maps zooms in to a out of bounds location.
What are we missing?

Re: Convert GPS coordinates to custom wkid

OscarMonell — Thu, 08 Mar 2012 09:46:57 GMT

function zoomToLocation(location) {
        var pt = new esri.geometry.Point(location.coords.longitude, location.coords.latitude, new esri.SpatialReference({ wkid: 4326 }));
       var outSR = new esri.SpatialReference({ wkid: 3008});
       gsvc.project([ pt ], outSR, function(projectedPoints) {
        pt = projectedPoints[0];

       map.centerAndZoom(pt, 8);
       });
}

Excellent!
Works like a charm!

Re: Convert GPS coordinates to custom wkid

DublinOhio — Sun, 12 Dec 2021 04:08:40 GMT

Just my more verbose version of the above, thanks for all the help everyone.

Here is our final way of getting this all to work

earlier in the code we (things you won't see in the code below):

dojo required a geometry service

defined a variable for a geometry service,

created a variable for our current location graphic

 function zoomToLocation(location) {


        // use this if basemap is WGS84 --- var pt = esri.geometry.geographicToWebMercator(new esri.geometry.Point(location.coords.longitude, location.coords.latitude));
        //otherwise, use this stuff below - basically we make a new point with the geolocated coordinates and reproject it, but to do so, you make the point
        //first and specify it's originating spatial reference so then you can reproject it to your own wkid

        var pt = new esri.geometry.Point(location.coords.longitude, location.coords.latitude, new esri.SpatialReference({wkid: 4236})); //don't forget to specify the originating wkid (in this case from the GPS/Geolocation)
        
        var outSR = new esri.SpatialReference({ wkid: 3735});
        gsvc.project([ pt ], outSR, function(projectedPoints) {[INDENT]       pt = projectedPoints[0];[/INDENT]
[INDENT]       map.centerAndZoom(pt, 8);[/INDENT]
[INDENT]       //add graphic at current location - if graphic exists just move it[/INDENT]
[INDENT]       if(!currGraphic){
          var symbol = new esri.symbol.PictureMarkerSymbol("images/i_runningman.png",40,40);
          currGraphic = new esri.Graphic(pt,symbol);
          map.graphics.add(currGraphic);
        }
        else{
          currGraphic.setGeometry(pt);
        }[/INDENT]
               });
        
      }