anodized platen is coated with about 40um of Teflon S touch-up lapping is 
more easily (and less precariously) done and produces a superior finish. 
Also, Teflon S (unlike aluminum) is amenable to finishing by single-point 
diamond turning which permits flatness on the order of +0.25jm to be achieved 
over a 23 x 23 cm format. 
Some of the operational functions of the CRC-1 are performed manually 
at the camera itself. These include, setting of shutter speed and aperture, 
setting of focus (principal distance) and setting of roll angle. The CRC-1 
has been so designed, however, that the camera can be completely remotely 
controlled through retrofitting of appropriate additional drives and encoders 
With such retrofitting the camera could, for example, be used for mensuration 
of structures in outer space along lines discussed in Brown (1980). 
Among the optional accessories available for the CRC-1 are the various 
lens cones mentioned earlier, a ring strobe capable of handling up to 1200 
watt seconds, a tripod and geared pan head, and self-adhesive retroreflective 
targets in a wide range of diameters. 
3.0 STARS SOFTWARE 
3.1 GENERAL 
The software package supporting STARS is written in FORTRAN 77 to run 
on a WICAT 150 desktop computer. The WICAT 150 is discussed in some detail 
in Section 4. A rather sizable manual would be necessary to provide full 
details of STARS software. It is therefore possible here only to touch on 
the highlights of the package, which may be described as being a program of 
the fifth generation (each preceding generation lasted an average of five 
years). As such, it embodies a host of refinements and extensions that have 
evolved from two decades of practical experience, | 
In recent years there has been a strong trend toward photographic 
coverage of objects using relatively large numbers of exposures instead of 
the two to five exposures dominant in the 60's and early 70's. During the 
past five years the majority of projects undertaken by GSI have involved 
coverage by from 8 to 20 photos. Another trend has been the increasing use 
of close-range photogrammetry for measurement of objects undergoing dynamic 
changes. This entails the use of multiple cameras rather than a single 
camera taking multiple photographs as is normally done for mensuration of 
static objects. This distinction between multi-camera and single-camera 
mensuration becomes important when consideration is given to the processes 
of self-calibration and rigorous propagation of error. 
To accomodate the above trends, STARS has been formulated to process close- 
range nets involving up to 24 exposures made in any combination by up to 6 
different cameras of which any or all may be uncalibrated. The heart of 
STARS consists of a bundle adjustment with self-calibration which has been 
specifically optimized for the special demands of close-range photogrammetry. 
However, STARS software also includes a number of auxiliary supporting pro- 
grams which are described briefly below. 
3.2 PREPROCESSOR 
As a given frame is measured on the comparator, the coordinates are 
transmitted through an RS-252C port directly to the computer which executes 
a number of real-time computations such as: automatically incrementing point 
8l