1. A system comprising: one or more computing devices, and memory storing instructions executable by the processor and a model comprising a plurality of model locations associated with geographic locations on a surface of a geographic feature, wherein the instructions comprise: determining a confidence value for a first model location of the model, where the confidence value is associated with a likelihood of the first model location being an accurate representation of a geographic location on the surface of the geographic feature; determining, with the one or more computing devices for a portion of the model comprising a plurality of model locations including the first model location, an eccentricity value based on a jaggedness of the surface according model locations; determining a reference shape defining a plurality of reference locations based on an estimate of the geographic locations of the surface of the geographic feature, a first reference location of the plurality of reference locations being a first distance from the first model location; and modifying the portion of the model by automatically moving the first model location and decreasing the first distance, wherein the amount of the decrease is larger when the confidence value is associated with a lower said likelihood and the eccentricity value is associated with a relatively jagged surface than when the confidence value is associated with a higher said likelihood and the eccentricity value is associated with a relatively smooth surface; and providing the modified portion of the model.