Hi, I have data that is simple local grid data (like from a total station). When I try and import it ArcGIS (10+) wants it to have a projection or it will not seem to use correct units (Metres) for doing nearest neighbour and other geospatial tasks or add other layers. This is just a local grid. How can you set up data with just a grid projection as there are not options for that in projections. I could use OSGB or UTM but that introduces other issues. How can I work with data in a metres based grid without upsetting Projection? Is it easy to set up a new projection that is a simple cartesan grid? Sorry if this is a basic question but I have not had to do this in the ArcGIS10 environment and it was not an issue in earlier versions (or as I remember) . Thanks in advance for any and all help.