A fundamental problem is deciding which technique to apply to the data and then estimating the error bounds on the results. VEG collects together in a common format technique previously available data from many different sources in a variety of formats. The decision as to when a particular technique should be applied is nonalgorithmic and requires expert knowledge. VEG has codified this expert knowledge into a rule-based decision component for determining which technique to use. VEG provides a comprehensive interface that makes applying the techniques simple and aids a researcher in developing and testing new techniques.
VEG also allows the scientist to incorporate historical databases into problem solving.
The scientist can match the target data being studied with historical data so the historical data can be used to provide the coefficients needed for applying analysis techniques. The historical data also provides more accurate error estimates than were previously available. VEG also provides a classification algorithm that can learn new classes of surface features. The learning system uses the database of historical cover types to learn class descriptions of one or more classes of cover types. These classes can include broad classes such as soil or vegetation or more specific classes such as forest, grass, and wheat.