Building a Production System to Support the National Digital Orthophoto Program: An Integration Challenge 
George Y. G. Lee and David C. Hooper 
U.S. Geological Survey 
345 Middlefield Road 
Menlo Park, CA 94025, USA 
Commission II, Working Group 5 
KEY WORDS: Orthoimage, photography, database, standards 
ABSTRACT 
The goal of the National Digital Orthophoto Program is to produce digital orthophoto coverage of the conterminous 
United States by the year 2001. The lack of budgetary and production resources necessary to complete this task requires 
the creative pooling of resources and performing the majority of the production work through contracts with private 
industry. The sudden demand for digital orthophotos also forced the U.S. Geological Survey to accelerate the 
development of its production system. The development task was particularly complex because of the integration issues 
involved with satisfying multiagency requirements, the legacy of data from analog production methods, and quality 
assurance issues associated with data produced by several contractors. The development of a production system without 
accepted standards prolonged the development cycle. The development was further complicated by a change to a 
distributed database strategy. 
INTRODUCTION 
The goal of the National Digital Orthophoto Program 
(NDOP) is to produce digital orthophoto coverage of the 
conterminous United States by the year 2001. À steering 
committee composed of Federal agencies and State 
organizations provides oversight and technical leadership 
for the program. The U.S. Geological Survey (USGS) is 
responsible for administering the program. The 
production strategy is to accomplish the majority of the 
work by contracting to firms in the private sector. This 
contracting strategy introduces a need for quality control 
tools within the production system. The digital 
orthophoto production system developed by the USGS in 
support of the digital orthophoto program evolved from 
a feasibility study and a prototype system. At the time, 
commercial software was not available in the United 
States to produce digital orthophotos. 
BACKGROUND 
The USGS, National Mapping Division, began producing 
analog orthophotos in 1964 using custom-built orthophoto 
equipment developed within the agency. For the next 25 
years, the agency produced analog orthophotos that often 
provided users with the only accurate base map in areas 
where the 7.5-minute topographic maps did not exist. 
During this period, the USGS also used three generations 
of commercially manufactured orthophoto equipment. 
In the late 1970's, the agency began its digital data 
programs that included digital elevation data as well as 
digital line graph data. The digital elevation data were 
collected, resampled, and formatted as a by-product of the 
analog orthophoto production process. In 1985, the 
National Mapping Division began its development of the 
current digital orthophoto system through a feasibility 
study made at its Western Mapping Center that 
demonstrated the generation of digital orthophotos from 
scanned diapositives using a minicomputer. Sample 
digital orthophoto products were created over the next 
several years and although they were received with much 
interest, there were no demands for a production 
implementation of the prototype system. A pilot project 
in Dane County, Wisconsin, which was presented at the 
first National Digital Orthophoto Forum in 1990, 
provided the impetus for nationwide coverage of digital 
orthophotography. 
During the development period, the agency produced 
analog orthophotos using the Wild OR-1 orthophoto 
system‘. The general lack of standards for analog 
components of the production process extended the 
development time for the system and ultimately required 
a system modification as standards were redefined. 
Furthermore, the transition period from an analog 
orthophoto generation process to a digital process created 
a legacy of digital and nondigital components, which 
added to the integration problem. Finally, new 
requirements and technology changes introduced new 
integration issues. This paper describes the evolution of 
the current production system and its current capabilities. 
224 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B2. Vienna 1996 
b: 
he 
Ol 
ar 
bi 
pt 
ce 
in 
th 
pr 
av 
an 
sti 
CO 
Th 
Col 
ac 
ph 
cy 
pri 
prc 
aei 
alr 
the 
not 
In 
the 
COI 
acc 
dig 
twi 
hoi 
pat 
sca 
slig 
Sin 
cali