Cartographic Results from Skylab 
Skylab was launched by NASA primarily to determine the ability of 
men to operate for extended periods in space. A second objective was 
a series of astronomical and solar physics experiments. The third- 
priority objective was a set of Earth observation experiments, two of 
which involved photographs (11). 
The first system was an array of 6 nearly identical cameras identi 
fied as S-190A. These cameras had a focal length of 150 mm and a format 
of 57x57 mm on 70 mm film, and covered a ground area of 165x165 km at an 
image scale of 1:2,900,000. The film and filters were selected to give 
4 black-and-white spectral bands approximately equivalent to those of 
the MSS on ERTS-1. Normal color and color infrared films were carried in 
the remaining 2 cameras. Flight patterns were designed to provide re 
peated coverage over a number of test areas in the United States. Because 
of the requirement to schedule photographic passes a day in advance, many 
of the photographs are obscured by partial or total clouds. A small amount 
of coverage was also obtained over other parts of the globe. 
Premission estimates of ground resolution were about 40 m for the 
normal color and high-resolution black-and-white films, and about 60 m 
for the color infrared and black-and-white infrared films. These values 
were obtained on the original film, but second-generation positives from 
the color films were degraded to nearly 80 m (12). The high-resolution 
black-and-white film easily withstands enlargement of more than 10X to 
scale 1:250,000. 
Most of the experiments conducted with the S-190A photographs have 
been designed to investigate multispectral signatures at higher resolution 
than is provided by ERTS-1. A few cartographic experiments have been 
undertaken but have not yet reached the stage of final production. A 
black-and-white mosaic of 4 frames from band 5 (0.6 to 0.7 ym) is being 
assembled at scale 1:250,000 as an image base for a map sheet of the 
Hartford, Conn, quadrangle,, The amount of cartographic treatment for 
this photomap has not yet been decided. An attempt has also been made 
to revise maps at scales 1:1,000,000 and 1:250,000, using enlargements 
of S-190A photographs. Published maps at these scales were compiled 
from larger scale maps and photographs, with consequent cartographic 
displacement .of features and severe generalization of shapes. The S-190A 
photographs show most of the mapworthy features, but in general the reso 
lution is inadequate for classification, and compilers are frustrated in 
deciding what they are looking at and whether it is worthy of change. No 
geometric accuracy tests have yet been made in these experiments.