When buffering features in a projected coordinate system with output to a geodatabase feature class, the geometries created may contain circular arc segments (when buffering points, the output will always be circular arcs). When using the Planar method, you can improve the accuracy of buffers created with projected inputs by using a projection that minimizes distance distortion, such as an Equidistant Conicor an Azimuthal Equidistant projection and is geographically appropriate for your input. You can change the coordinate system of a feature class using the Project tool, or you can set the Output Coordinate System geoprocessing environment before executing the Buffer tool, and this coordinate system will be used in creating buffers. In some cases this may take more time than the geodesic buffer created using the Planar option, but the result is a buffer that more accurately matches the shape of the input feature. If you are concerned about the shape of your buffers and how closely their shape matches the original input features, it is recommended you investigate using this option, particularly when your input data is in a geographic coordinate system. The shape-preserving geodesic buffer densifies the input features prior to creating the output geodesic buffers in order to create buffers that more closely represent the input features shape. Geodesic (method = "GEODESIC" in Python) creates a shape-preserving geodesic buffer regardless of the input coordinate system.This option produces the same result as the Buffer tool prior to ArcGIS 10.3.If the input features have a geographic coordinate system and you specify a Buffer Distance in linear units (meters, feet, and so forth, as opposed to angular units such as degrees), geodesic buffers will be created.If the input features have a projected coordinate system, Euclidean buffers will be created.This option will automatically determine which method to use based on the coordinate system of the Input Features. Planar (method = "PLANAR" in Python) is the default option.The Method parameter determines how buffers are created. For more information, see How Buffer works. Geodesic buffers may appear unusual on a flat map, but when displayed on a globe, these buffers will look correct (you can also use a 3D scene or ArcGIS Earth to view geographic data on a three-dimensional globe). The spatial reference (map projection) of your input features distorts distances in order to preserve other properties such as area.Your input features are dispersed (cover multiple UTM zones, large regions, or even the whole globe).You should always consider creating geodesic DistancesĪre calculated between two points on a curved surface (the geoid) as opposed to two points on a flat surface (the Cartesian plane). Relatively small area (such as one UTM zone).Īccount for the actual shape of the earth (an ellipsoid, or more properly, a geoid). Euclideanīuffers are the more common type of buffer and work well whenĪnalyzing distances around features in a projected coordinate system, which are concentrated in a Euclidean buffers measure distance in a two-dimensionalĬartesian plane, where straight-line or Euclidean distances areĬalculated between two points on a flat surface (the Cartesian plane).There are two basic methods for constructing buffers: Euclidean and geodesic. As described in How Buffer works, an important feature of the Buffer tool is the Method parameter which determines how buffers are constructed.