Variable Gradient Geospatial Smoothing
Similar to the general Variable Gradient Smoothing concept, Variable Gradient Geospatial Smoothing seeks to take advantage of neighboring data points in a way that is more responsive where possible, yet more stable where necessary. The difference is that it operates in two dimensions across a geographical surface.
When a characteristic is identified by the user as ZIP 5, County FIPS 5, State FIPS 2, or Custom Geographic, Variable Gradient Geospatial Smoothing is used. The physical distance between the ZIP Code, County, State, or Territory population weighted centroids determines the level of data aggregation, in conjunction with the radius. Like Variable Gradient Smoothing, multiple radii are used.
The default Radii are: [0 (no smoothing), 5 km, 10 km, 20 km, 50 km, 100 km, 300 km]. These radii can be modified by the user in the Characteristic Selection screen.
The weight applied to geographical data is equal to radius4 / (distance4 + radius4), where distance is the distance from the geographical area for which the factor is being calculated.
Refer to the help screen on Variable Gradient Smoothing for more information.