-9- 
The second photographic experiment on Skylab was a single long- 
focal- length camera known as S-190B. It had a focal length of 460 mm and 
a format of 115 x 115 mm and covered a ground area of 109 x 109 km at an 
image scale of 1:945,000. Several different films were used at different 
times, but most of the pictures were taken with color (S0-242) or color 
infrared (3443) film. On Skylab 4, a new color infrared film (SO-131) 
wifh a resolution comparable to that of the best normal color film was 
carried. The first pictures look excellent but have not yet been evaluated. 
The coverage pattern for S-190B is similar to that for S-190A, except 
that the ground track is narrower and, of course, only one kind of film 
could be used at a time. The flight pattern makes it difficult to find 
complete coverage of any standard map sheet. 
As with S-190A, cartographic experiments with S-190B are just 
beginning. The resolution of the photographs seems most compatible with 
map scale 1:100,000, which unfortunately is not yet a standard scale in 
the United States. 
A State base mosaic is being assembled for Connecticut from black- 
and-white enlargements of the original color image. The scale will be 
1:125,000 to match the published line-drawn base map. Some small gaps 
may be filled in with high-altitude U-2 photographs if an adequate match 
can be attained. Cartographic enhancement, if any, is yet to be determinedi 
Two map revision projects at scale 1:100,000 have been started. The first 
is monoscopic revision of the Sonoma County map in California. * The second 
is a stereocompilation at 1:100,000 (in the Kern PG-2 or the AS-11A) for 
Montgomery County, Md. In both cases the original photographs are in' 
color. Preliminary estimates are that feature classification will be 
much easier than with the S-190A photographs. 
Conclusions , „ ■ 
— ■ . .T I». 
1 ■, ■. ■ - 
It has been amply demonstrated that ERTS-1 images can be transformed * 
into cartographic products, both black-and-white and color at scales 
1:500,000 and 1:1,000,000. The resolution is inadequate for scale 
1:250,000 except for areas where terrain morphology is the principal 
cartographic features and cultural features are absent. NMAS can be 
met at scales up to 1:500,000 by fitting the UTM to black-and-white and 
color mosaics of several images, or at scale 1:250,000 for single blacks . • 
and-whi^e images or by digital manipulation of the multiband data. The 
utility and demand for these small-scale products as adjuncts to multi- 
spectral interpretation remain to be determined. 
It is most probable that S-190A photographs from Skylab will prove 
useful for photoimage base maps and, with less certainty, for map revision 
at the scale of 1:250,000. Photographs from S-190B will be useful for 
compilation and revision at 1:100,000 and possibly at scales as large as 
1:62,500 or 1:50,000. Except for scientific and historical purposes, the 
Skylab photographs are already obsolescent, and no more are to be expected.