549 
ANALYTICAL SYSTEMS FOR DATA REDUCTION WITH IMAGERY OF 
EXTRATERRESTRIAL BODIES 
Dr. Sherman S. C. Wu, Supervisory Physical Scientist 
United States Geological Survey, Flagstaff, AZ 86001 
USA 
Commission II 
ABSTRACT 
Imagery of extraterrestrial bodies has been, and in the future will 
continue to be, acquired by a wide variety of sensors. Examples of such 
images are Hasselblad, metric and panoramic camera images of the Moon, 
vidicon and facsimile camera images of Mars, and radar images of Venus, 
etc. Topographic information of extraterrestrial bodies is derived using 
these images on various analytical stereoplotters, AP/C, AS-11A, and AS- 
11B-l as well as using pure analytical solutions. Because of the extremely 
narrow field-of-view of the Viking vidicon cameras, special techniques were 
developed for the photogrammetric compilation from stereoscopic photographs 
of Mars from the two Viking Orbiter spacecraft. Using imagery taken by 
facsimile cameras, the most accurate methods of mapping the two Viking 
Lander areas were to make all image conversions and corrections in real 
time on an analytical stereoplotter. Using panoramic photography of the 
Moon, lunar maps were compiled using special software programs on the 
analytical plotters. Technical derivation and software development are 
reviewed. Development of stereo radar compilation using analytical 
stereoplotters is also discussed. 
I. INTRODUCTION 
Topographic mapping of extraterrestrial bodies differs in many ways from 
the mapping of Earth. It involves solving many unprecedented problems: 
the lack of precise ground controls, the absence of oceans to provide a 
zero-elevation reference surface, and methods of data acquisition, etc. 
These unconventional factors require the development of new methodologies 
and new equipment. Because of the fact that most of the planetary missions 
were not specifically planned for making three-dimensional photogrammetric 
measurements, stereo models, in many cases, can be constructed only by 
pictures that were taken from camera stations in different orbits. As a 
consequence, the pictures of the stereo models have different flight 
heights, a different appearance of the same surface area caused by 
shadowing effects from different sun angles, and very unusual model 
geometry. However, in some cases, high-quality cameras capable of making 
reliable measurements for topographic mapping were carried aboard orbiting 
spacecraft such as the Apollo 15, 16, and 17 missions. In fact, the 
photogrammetric system installed in the scientific instrument module bay of 
the Apollo service module (metric-, panoramic-, and stellar-camera and a 
laser altimeter) provide almost everything that a photogrammtrist could 
want. 
Remote sensing data, imaging or nonimaging, from devices using a broad 
spectrum of wavelengths play an important role in planetary topographic 
mapping. This paper discusses analytical systems for map compilation and 
data reduction with planetary images from various planetary missions, 
Apollo, Mariner, and Viking Mars, as well as the planned Venus Radar 
Mapper. Planetary images include those that have been and those that will 
be acquired by various cameras, metric, panoramic, vidicon cameras as well 
as other remote sensing devices such as the synthetic aperture radar 
systems.