Use of Digital Terrain Data for Project Estimating

A new method of preparing cost estimates for transmission lines has been developed. Elevation data extracted from magnetic tapes compiled by the Defence Mapping Agency (DMA) is used as input to a computer program that estimates the quantity of tower steel required. Variations in the quantity of tower steel generally accounts for the largest proportion of the per mile cost differences between transmission lines of the same design. Provided a digital terrain data base of sufficient accuracy is available, this form of data may be utilized to estimate the cost of any topographically dependent construction project. Digital terrain data have also been used for a number of other interesting applications, one of these being the visual analysis of a facility's impact. These various applications of digitized elevation data along with a general description of the procedures used in generating a digital terrain model are considered.