Mars is being mapped with digital television images returned 
by the Mariner 9 spacecraft. The Mariner 9 spacecraft was equipped 
with two narrow-angle vidicon television cameras. It returned data 
from Martian orbit from November 1971 through October 1973. A de- 
tailed description of the Mariner 9 mission is contained in Masursky 
and others (1970). The mapping effort is described by Batson (1973a), 
and Batson (1976). Photogrammetric triangulation, discussed by Davies 
and Arthur (1973). and Davies (1973), was used to derive planimetric 
controls for mapping. A series of shaded relief maps at 1:5,000,000 
is being compiled by a combination of image processing, controlled 
mosaicking, and airbrush techniques (Batson, 1973b). 
Stereophotogrammetry for measurement of Martian surface-relief 
is possible with only a small number of Mariner 9 frames (Blasius, 
1973, Wu and others, 1973). Systematic topographic measurements 
for compilation of contour maps of the entire planet were done by 
a variety of non-photogrammetric methods, including Earth-based 6 
radar altimetry, spectroscopic measurement of atmospheric density | 
and times of spacecraft occultations by the planet. Utilization of 
the data for contour mapping is discussed by Wu (1976) and Christensen 
(1975). Measurement of a horizontal and vertical control net for 
Phobos was done with Mariner 9 pictures by Duxbury (1974), but map 
compilation has not yet begun. 
The planet Mercury is being mapped with digital television 
pictures returned by the Mariner 10 spacecraft. The Mariner 10 space- 
craft is similar to Mariner 9, except that both Mariner 10 cameras 
had focal lengths of 1500 mm, instead of 50 mm and 500 mm on Mariner 9. 
Mariner 10 is in orbit around the sun instead of around Mercury, so 
the gathering of data was limited to three flybys of the planet. 
Since each flyby took place at the same time in the Mercurian day, 
the same half of the planet was illuminated in all data sets. A 
description of the Mariner 10 mission is contained in Murray (1975), 
Strom and others (1975), and Danielson and others (1975). 
Compilation of a series of nine shaded relief maps at 1:5,000,000 © 
is under way (Davies and Batson, 1975). These maps are compiled by 
methods similar to those used in compiling the Mars maps.  Stereophoto- 
grammetry is possible with pictures taken on the first and second 
flybys of Mercury, but has not yet been incorporated in the mapping. 
REFERENCES 
Batson, R. M., 1973a, Cartographic products from the Mariner 9 mission: 
Jour. Geophys. Research, v. 78, no. 20, p. 4424-4435. 
---- 1973b, Television cartography: U.S. Geol. Survey Interagency 
Rept. 58, p. 1-32. 
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