Summary
Creates buffer polygons around input features to a specified distance
Usage
- As described in How Buffer works, an important feature of the Buffer tool is the Method parameter which determines how buffers are constructed. There are two basic methods for constructing buffers: Euclidean and geodesic.
- Euclidean buffers measure distance in a two-dimensional Cartesian plane, where straight-line or Euclidean distances are calculated between two points on a flat surface (the Cartesian plane). Euclidean buffers are the more common type of buffer and work well when analyzing distances around features in a projected coordinate system, which are concentrated in a relatively small area (such as one UTM zone).
- Geodesic buffers are those that account for the actual shape of the earth (an ellipsoid, or more properly, a geoid). Distances are calculated between two points on a curved surface (the geoid) as opposed to two points on a flat surface (the Cartesian plane). You should always consider creating geodesic buffers when
- Your input features are dispersed (cover multiple UTM zones, large regions, or even the whole globe).
- The spatial reference (map projection) of your input features distorts distances in order to preserve other properties such as area.
Geodesic buffers may appear unusual on a flat map, but when displayed on a globe, these buffers will look correct (you can also use the ArcGlobe or ArcGIS Explorer applications to view geographic data on a three-dimensional globe). For more information, see How Buffer works.
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