topic Need help regarding suitable projection for base map and dynamic map in ArcGIS JavaScript Maps SDK Questions

Need help regarding suitable projection for base map and dynamic map

SunilPalkar — Thu, 11 Oct 2012 12:49:32 GMT

Hello All,

Good Morning,

I have lot of geographic data in shape file format and we are going to host few data on server 10.1 [and then will publish in Java script API (v 3.0) ] . I recently gone following article regarding projections http://blogs.esri.com/esri/arcgis/2009/11/20/arcgis-online-moving-to-google-bing-tiling-scheme-what-does-this-mean-for-you/ it states that you need to convert your projection to WGS 1984 Web Mercator.

I have already shape files in WGS 84 (degree) format & My question is that Do I need to convert all these shape files to WGS 1984 Web Mercator format ?? ( Because I want to use this data for ArcGIS Server(10.1) and then in JSAPI for custom applications)

Any help/suitable methodology is highly appreciated..

Thanks in advance : )

Re: Need help regarding suitable projection for base map and dynamic map

JohnGravois — Thu, 11 Oct 2012 21:41:32 GMT

hi steve,

you can certainly publish your shapefile data in WGS84. the reason it is often suggested to reproject to web mercator is so that you can mash things up with google/esri//bing/osm without asking your own dynamic map and feature layers to reproject on the fly. depending on the data you are trying to display, this can give a noticeable performance improvement.

the blog you linked warns specifically about caching services in a projection other than web mercator. this is because it is NOT possible to overlay two different tiled map services that use different coordinate systems.

Re: Need help regarding suitable projection for base map and dynamic map

SunilPalkar — Fri, 12 Oct 2012 03:56:09 GMT

Dear John,

Thanks for your reply.. I like your post and justification ..

You are simply great !!!

Thanks : )

hi steve,

you can certainly publish your shapefile data in WGS84. the reason it is often suggested to reproject to web mercator is so that you can mash things up with google/esri//bing/osm without asking your own dynamic map and feature layers to reproject on the fly. depending on the data you are trying to display, this can give a noticeable performance improvement.

the blog you linked warns specifically about caching services in a projection other than web mercator. this is because it is NOT possible to overlay two different tiled map services that use different coordinate systems.