The subscene transparencies were enlarged, without 
rectification, to a nominal 1:100,000-scale from the 
original 1:500,000-scale. The RBV subscene at this scale 
permits a one-to-one scale registration to the planimetric 
base separate. Any small misregistration in localized 
areas was eliminated by a slight shift of the RBV subscene 
to the separate. The planimetric base separates, 
overlayed on the RBV subscene transparency, were viewed on 
a light table. 
Because there is little relief displacement in the areas 
revised, the overlay provided a quick scan of all linear 
features on the base separate. Subdivisions of new 
housing, urban built-up areas, road networks, interstate 
highways, powerlines, pipelines, woodland boundaries, and 
shorelines were identified using existing quad centered 
photographs as a guide. 
New features were then compiled directly from the RBV 
transparency onto the base separate. Limitation of RBV 
imagery for revision includes the inability to identify 
such features as highway overpasses and road networks in 
urban built-up areas. 
CONCLUSION 
RBV images provide a source material for photoinspection, 
i.e., "the comparison of existing maps to recent source 
material to determine the amount of change, the need for 
revision, and recommendation for the type of revision." 
(USGS, 1978). In certain instances of limited revision 
("the correction of specific map deficiencies and the 
updating of selected map content") (USGS, 1978) such as 
the insertion of interstate transportation networks on 
intermediate and small-scale maps, RBV images are also of 
value. Because of their geometric fidelity, revision can 
be accomplished by simple enlargement to map scale. This 
geometric fidelity permits image mosaicking to accuracy 
approaching and in some instances surpassing the National 
Map Accuracy Standards. 
References 
Bender, L.U., 1970, An Algorithm for Gridding Satellite 
Photographs: Reports of the Department of Geodetic 
Science, Report No. 135, The Ohio State University Research 
Foundation, April 1970. (USGS Contract No. 14-08-0001- 
119996) 
U.S. Geological Survey, 1976, RCA Return Beam Viaicon (RBV) 
Reseau Coordinates for Landsat-C: U.S. Geological Survey 
Topographic Division 
U.S. Geological Survey, 1978, 7.5 Minute Map Revision: 
Internal Memo, pp. 2 
U.S. Geological Survey, 1979, Landsat Data Users Handbook, 
revised edition, pp. 4-9