topic Missing Spatial Reference in ArcGIS Spatial Analyst Questions

Missing Spatial Reference

SafiatAmuwo — Fri, 15 Jul 2011 05:42:03 GMT

Hello anyone and everyone,

I am currently in a HPA/EOHS course at UIC. Our assignment requires us to download Census 2000 TIGER/Line Shapefiles. After downloading and unzipping these shapefiles, I received 4 shapefiles (tgr1700sf1trt.dbf, tgr17097trt00.dbf, tgr17097trt00.shp, and tgr17097trt00.shx). When attempting to add the shapefile "Tgr1709trt00.sph" to the Table of Contents, I received an error.

This error states "the following data sources you added are missing spatial reference information. This data can be drawn on ArcMap, but cannot be projected." What can I do to fix this problem? PLEASE HELP

Re: Missing Spatial Reference

michaelcollins1 — Fri, 15 Jul 2011 10:55:33 GMT

Go to ArcGIS Help and type in "Specifying a coordinate system"

Re: Missing Spatial Reference

SafiatAmuwo — Sun, 17 Jul 2011 15:12:08 GMT

Go to ArcGIS Help and type in "Specifying a coordinate system"

After searching "specifying a coordinate system", I followed the steps but my current coordinate systems says "UNKNOWN". Note: one or more layers is missing spatial reference information. Data from these layers cannot be projected.

After importing the data source that is defined with the coordination system I want to use; Under < custom > it states UNKNOWN. If there anything else I can do? I followed the steps shown, but it does not work for me. Please HELP

Re: Missing Spatial Reference

PavanYadav — Tue, 19 Jul 2011 00:30:42 GMT

After searching "specifying a coordinate system", I followed the steps but my current coordinate systems says "UNKNOWN". Note: one or more layers is missing spatial reference information. Data from these layers cannot be projected.

After importing the data source that is defined with the coordination system I want to use; Under < custom > it states UNKNOWN. If there anything else I can do? I followed the steps shown, but it does not work for me. Please HELP

Greetings,
Most likely your shapefiles have Geographic coordinates NAD83 for the 48 contiguous states, NAD27 for Alaska, and Old Hawaiian Datum for Hawaii. Use the Define Projection to define the projections.

To define projection, open the Define Projection tool (Data Management toolbox) > input your shapefile > For the coordinate system parameter, click the browse button > Expand the Geographic Coordinate Systems folder > Expand �??North America�?? folder > Select NAD 1983 or NAD 1927 > Click OK > Click OK.

You might find these ArcGIS web-help and Knowledge Based articles helpful:

Define Projection (Data Management)
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//001700000077000000.htm
FAQ: Projection Basics: What the GIS professional needs to know
http://support.esri.com/en/knowledgebase/techarticles/detail/23025
HowTo: Identify an unknown projected coordinate system using ArcMap
http://support.esri.com/en/knowledgebase/techarticles/detail/24893
HowTo: Select a suitable map projection or coordinate system
http://support.esri.com/en/knowledgebase/techarticles/detail/24646

Regards,
Pavan

Re: Missing Spatial Reference

BrandonMill — Tue, 02 Aug 2011 14:54:13 GMT

Hello

I am having the same problem except when I use the define project tool it disappears from view. I have zoomed to layer and it just stays in the same spot. Why does it go away?