SURGE experiments
E 5,
A LARGE FORMAT CAMERA FOR SHUTTLE
Frederick J. Doyle
U.S. Geological Survey
Abstract
NASA is building a high performance cartographic camera with 30.5 cm
focal length and 23 x 46 cm format. Initially the camera will be
carried in the cargo bay of early Shuttle flights. From a nominal
altitude of 300 km, each frame will cover 225 x 450 km with a ground
resolution of 14 to 25 m depending upon the choice of film. With the
long dimension of the frame in the direction of flight, base-height
ratio of up to 1.2 can be obtained permitting compilation of topographic
contours at 20 to 30 m intervals.
If the photography from the sortie missions proves to be as useful as
expected, the camera will be mounted in a free-flying spacecraft which
can be placed in near polar orbit and remain operational for many months
with film being recovered and returned to Earth by the Shuttle.
From the time that the first space photographs were made with a hand-
held Hasselblad camera on the Gemini missions, photogrammetrists have
considered that orbiting spacecraft should be the next step in the
logical progression from planetable to aerial photography, to space
photography. But despite the widely acclaimed success of the Landsat
program, photogrammetrists have generally been dissatisfied with the
low resolution and the lack of Stereocoverage which prevent the Landsat
imagery from contributing to conventional Stereomapping programs.
As long ago as 1967, the National Academy of Sciences Committee on the
Useful Applications of Earth Oriented Satellites recommended a camera
svstem which would contribute to worldwide topographic mapping. The
recommended approach comprised a cartographic frame camera to be used
for establishing control and a panoramic camera to provide the resolution
needed to compile planimetric detail. The fundamental feasibility of
this approach was demonstrated on the Apollo 15, 16, and 17 missions
where a similar system was carried into lunar orbit. Based on the meas-
urement of these photographs, a lunar control net with an internal con-
sistency of 30 m in all three coordinates has been developed, and
topographic orthophotomaps at scales as large as 1:25,000 have been
produced. Such a system has been proposed to NASA for operation in
Earth orbit on several occasions, but for a variety of reasons the system
has never been implemented.