How To: Align vector data in ArcMap
ArcMap has a utility that projects data on the fly, which allows ArcMap to display data stored in one projection as if it were in another projection without altering the data. This occurs when the data has a layer with a different coordinate system definition than the coordinate system of the data frame. ArcMap will not project data on the fly if the coordinate system for the data set has not been defined.
ArcMap expects coordinate system information to be stored with the data source.
Define a projection for the dataset.
- Geodatabase, Shapefile, and Coverage data
For a layer in a geodatabase, the coordinate system information is part of the layer's metadata. For coverages and shapefiles, the coordinate system information is stored on disk in a separate file.
You can define a coordinate system for a dataset in ArcCatalog or ArcToolBox.
¤ Shapefile and geodatabase1. Right-click the vector file.¤ Coverage (ArcInfo and ArcEditor License only)
2. Click Properties.
3. Click the Spatial Reference tab.
4. Click the Edit button.
5. Click the Select button.
6. Navigate through the folders until you find the coordinate system you want and select it.
7. Click OK.
See: How To: Define a coordinate system interactively for a coverage using ArcCatalog
See: How To: Define a projection for a shapefile to a predefined coordinate system ¤ Geodatabase
See: How To: Define a custom projection for a geodatabase ¤ Coverage
See: How To: Define a coordinate system interactively for a coverage
- CAD data
When you use CAD drawings, there is no guarantee the drawing will be in the same coordinate system as your other layers. You can apply a coordinate transformation to your CAD layers to make sure they overlay with your other layers.
The following methods are available to transform CAD data.
¤ Transform by World File
See: How To: Transform CAD data in ArcMap to line up with other data¤ Transform by Coordinate
¤ Transform by Rotate, Scale, and Translate
See: How To: Transform the coordinate location of a CAD file using a rotate, scale, translate transformation