IMPLEMENTATION OF SOFTCOPY PHOTOGRAMMETRIC WORKSTATIONS AT THE UNITED-STATES GEOLOGICAL SURVEY

The U.S. Geological Survey has provided the Nation with primary quadrangle maps and map products for the last 50 years. The Survey recently completed initial coverage of the conterminous United States and Hawaii at 1:24,000 scale. In Alaska, complete coverage exists at 1:63,360 scale. Effort is underway to build a National Digital Cartographic Data Base (NDCDB) composed of the digital representation of these and other map series. In addition, the Survey plans to meet the demand for more current and complete data through the development and promotion of spatial data standards in cooperation with other Federal, State, local, and private organizations. Plans for a digital revision program call for the extensive use of softcopy monoscopic workstations to serve as the mechanism for revising the planimetric digital data layers. These workstations will be supplemented by analog and analytical photogrammetric workstations to handle hypsography and some amount of feature classification. The advent of a digital orthophotograph production capability, coupled with workstation technology, has directed this trend. The Geological Survey has initiated two research projects to study digital orthophotograph production and revision processes.