Just a quick question on what co-ordinate system I should be using for all our data. All our information is stored in OSGB 1936, projected to British National Grid. However I have found that to be able to use the ESRi World Geocoder in the Locate tool in ArcGIS Pro accurately, the map I'm using needs to be in WGS 1984 (projected to Web Mercator). This does cause a little bit of slowdown in the map however, presumably as all the layers are being re-projected on the fly to line up with the maps PCS.
My questions are
- As a general rule, should I stick with using British National Grid for everything? Our data is only UK based, and currently only covers a single local authority.
- We use ArcGIS Online a lot, with our own custom basemap (that should also be based on British National Grid, as its taken from OS Data). Would we notice any speed increase if everything was in fact in Web Mercator? I don't know if just the overall 'structure' of ArcGIS Online is Web Mercator based and thus we would notice speed increase, even though currently everything is in the same format.
Thanks for any help in advance