The past two decades have seen extraordinary growth in the demand for geo-spatial data. This demand has numerous sources and takes many forms; however, the net effect is an ever-increasing thirst for data that is more accurate, has higher density, is produced more rapidly, and is acquired less expensively. Unfortunately, traditional techniques for collecting spatial data, such as conventional surveying techniques, point-wise GPS, or aerial photogrammetry, have difficulties satisfying many of the new data collection requisites. Conventional surveying or point-wise GPS are, for instance, poorly suited for the rapid and inexpensive collection of data over large areas. Traditional aerial photogrammetry, while satisfying these needs, is disadvantaged by the requirement to establish moderately dense and expensive ground control.