We have experimented with 3 weighting functions, all of which result in cells that are farther from the focus cell having less weight than cells which are closer to the filter focus. We have produced a filter where the weighting decreases linearly with increasing distance from the focus, one where the weights decrease as reciprocal distance, and one where weights decrease as inverse distance squared. All of the simulations shown here use the results from the reciprocal distance erosion filter.
The radius of the filter is adjustable. The radius of the filter has a rather minor effect on the filter results, since the weights cause cells farther from the focus to have diminishing effects anyway. Experimentation has shown that pleasing results are produced with a radius of 105 meters, and this is the radius that has been used for the simulations shown here.
If the depth at the center focus cell is higher than the weighted average of the surrounding local environment, the filter indicates that potential erosion could occur at this spot. On the other hand, if the center focus cell is at a local low spot relative to its surroundings, the filter indicates that potential deposition could occur here. The behavior of the filter is log-transformed, since very deep ``holes'' or very tall ``peaks'' would not be that much more likely to erode or deposit than shallower ones.
The Erosion filter can predict only potential erosion and deposition, since, for example, the existence of local low spots does not guarantee the availabliity of sediment to deposit there.