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USGS Western Region

The Leader in Orthoimagery

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National Petroleum Reserve-Alaska High-resolution digital orthophoto and elevation study area in Alaska
The T-64 Orthophotoscope, the first instrument used in Menlo Park for the analog production of orthophotos

Conventional aerial photographs contain image distortions caused by the tilting of the camera and terrain relief. The process of orthorectification removes these distortions and creates an orthophoto—an image that looks like an aerial photograph yet has the uniform scale and planimetric accuracy of a map.

Orthophoto production began at the USGS Western Mapping Center (WMC) in Menlo Park, California (now called the Western Geographic Science Center), in 1965 using the T-64 Orthophotoscope, designed and built in 1964 by Russel Bean at USGS headquarters in Virginia. Several generations of this analog process were used through the early 1980s, but production was very labor intensive and done primarily in-house. Analog orthophotos were derived primarily from high-altitude, 1:80,000-scale aerial photographs and were produced in 7.5-minute units.






Throughout the 1970s, technicians at the USGS Western Mapping Center developed numerous innovative photographic techniques to improve their methods and the quality of their products




Among the many limiting factors in the creation of high-quality analog orthophotos were problems related to equipment limitations and restrictive film properties. Throughout the 1970s, technicians at the WMC developed numerous innovative photographic techniques to improve their methods and the quality of their products. Significant examples include developing a way to use new high-contrast lithographic duplicating film to create machine-processed continuous-tone images, and developing a computer technique for reliable film exposures and processing controls. These innovations, coupled with technological developments in computerization, were a tremendous catalyst in gaining approval for an intensified orthophoto development program.


National Petroleum Reserve-Alaska High-resolution digital orthophoto and elevation study area in Alaska
DOQ of northeastern San Francisco and the Bay Bridge, 1993.


The continued development of the orthophoto program at the WMC was strongly supported by a progression of key leaders at the Center, and in the late 1980s, a convergence of events centered around the USGS Western Mapping Center allowed orthophoto technology to take a giant leap forward. In the early 1980s, WMC staff created notes and algorithms for a digital method to produce orthophotos that could potentially allow orthophotos to be produced much more quickly and easily than using the analog method, but computers were not fast enough and lacked sufficient memory to effectively utilize this process. Computer technology, however, improved rapidly, and in 1986 the WMC proposed and was granted approval to develop a prototype digital orthophoto quadrangle (DOQ) production system. The primary objectives were to develop a more efficient mehod for producing hard-copy orthophotos and to create a digital product that users could manipulate and use as a base for displaying geographic information system (GIS) data


At the same time the U.S. Department of Agriculture (USDA) was looking for an efficient method of producing up-to-date maps of the Nation’s soils—a task that could be greatly facilitated with the use of DOQs. When USDA officials became aware of the work being done at WMC, an agreement was developed for the USDA to provide funding for preliminary production of large quantities of DOQs. The USDA wanted a higher resolution product than could be created using 1:80,000-scale aerial photographs, so the DOQs were based on a new 1:40,000-scale aerial photograph program that yielded a 3.75-minute format (one-fourth of a standard 7.5-minute quadrangle, or a “quarter quadrangle”) and approximately 1-meter resolution.



Full-scale production of DOQs at the WMC began in 1991, when a total of 65 DOQs were delivered. In 1993, when technical specifications for developing DOQs were finalized, the USGS joined with the USDA and other Federal agencies to create the National Digital Orthophoto Program to ensure public domain availability of DOQ data for the entire Nation. In that same year, 2,600 DOQs were created in-house at WMC, and 2,804 DOQs were contracted out. All DOQs produced by contractors had to be routed back through the WMC for evaluation and validation. WMC employees worked in three shifts, 24-hours per day to meet the work demand.



National Petroleum Reserve-Alaska High-resolution digital orthophoto and elevation study area in Alaska
The 4.5-ton Robertson 48-inch copy camera used for photographic-reproduction scale-change requirements in the initial orthophoto production efforts.

DOQ production continued to accelerate and peaked in 1999 when WMC was responsible for contract production and in-house production of 47,000 DOQs. By 2000, the WMC had directed a total of nearly $100 million to private sector mapping contractors and had been responsible for the creation of 168,000 DOQs. In 1999, the Western Mapping Center’s DOQ program received the Unit Award for Excellence of Service from the Department of the Interior.



In 1997, the WMC and Microsoft Corporation entered into a Cooperative Research and Development Agreement to make DOQs easily available to the public through the TerraServer USA Web site, which receives nearly 40,000 hits per day.



The DOQ program at WMC tapered off soon after 2000 because coverage of the conterminous United States was nearly complete and production and contracting responsibilities for DOQs had been moved to the USGS mapping center in Rolla, Missouri. Only a small number of second- and third-generation DOQs and some historical orthoimages are still being produced in Menlo Park, but the Western Mapping Center remains the leader in establishing and completing, within 10 years, first-time coverage of the conterminous United States with DOQs.


National Petroleum Reserve-Alaska High-resolution digital orthophoto and elevation study area in Alaska
In the aerial photograph at left, a pipeline trending southeast to northwest is seen as a curvy line due to distortions caused by the terrain. In the DOQ at right, the distortions have been corrected, and the pipeline is seen in its true state as an almost straight line.