GIS data often comes from many sources. Inconsistencies between data sources sometimes require you to perform additional work to integrate a new dataset with the rest of your data. Some data is geometrically distorted or rotated with respect to your base data.
Within the editing environment, the spatial adjustment tools provide interactive methods to align and integrate your data. Spatial adjustment supports a variety of adjustment methods and will adjust all editable data sources. It's often used when you've imported data from another source, such as a CAD drawing. Some of the tasks you can perform include converting data from one coordinate system to another, correcting geometric distortions, aligning features along the edge of one layer to features of an adjoining layer, and copying attributes between layers. Since spatial adjustment operates within an edit session, you can use existing editing functionality, such as snapping, to enhance your adjustments.
Spatial adjustment commands and tools are located on an additional editing toolbar called the Spatial Adjustment toolbar.
Along with the ability to spatially adjust your data, the Spatial Adjustment toolbar also provides a way for you to transfer the attributes from one feature to another. This tool is called the Attribute Transfer tool and relies on matching common fields between two layers.
Together, the adjustment and attribute transfer functions available on the Spatial Adjustment toolbar allow you to improve the quality of your data.
An overview of the spatial adjustment process
While each of the spatial adjustment functions is used for a different purpose, the steps for setting up and performing an adjustment are essentially the same:
- Start ArcMap.
- Create a new map or open an existing one.
- Add the data you want to edit to your map.
- Add the Editor toolbar to ArcMap.
- Add the Spatial Adjustment toolbar to ArcMap.
- Start your edit session.
- Choose the input data for the adjustment.
- Choose a spatial adjustment method.
- Create displacement links.
- Perform the adjustment.
- Stop your edit session and save your edits.
There is no need to save the map—all edits made to the database will automatically be reflected the next time you open the map.
References used in the spatial adjustment help
Maling, D.H. Coordinate Systems and Map Projections. George Philip, 1973.
Maling, D.H. "Coordinate Systems and Map Projections for GIS." In: Maguire, D.J., M.F. Goodchild, and D.W. Rhind (eds.), Geographical Information Systems: Principles and Applications, Vol. 1, 135–146. Longman Group UK Ltd., 1991.
Moffitt, F.H., and E.M. Mikhail. Photogrammetry, Third Edition. Harper & Row, Inc., 1980.
Pettofrezzo, A.J. Matrices and Transformations. Dover Publications, Inc., 1966.
Slama, C.C., C. Theurer, and S.W. Henriksen (eds.). Manual of Photogrammetry, 4th Edition. Chapter XIV, 729–731. ASPRS, 1980.