payoff is expected to occur with the image-mat-
ched filter.
Heterodyned optical correlator. - The idea
of heterodyne coincidence detection is used in
coherent optical correlation (Mikhail, 1975 ;
Mikhail and Gifford, 194g) for automating con-
tour data generation. Correlation may be in
model space (using a holographic stereomodel)
or in image space. For correlation in model spa-
ce, a sensor array is connected to a digital com-
puter. The position of an element in the array
at which the correlation coefficient is maxi-
mum is designated as a point on a contour line.
Therefore all points on a particular contour
within the area covered by the sensor array are
extracted at once. The system appears promi-
sing and is currently being further analyzed.
Recording | Optical Spectrum Analyzer
(ROSA). - Diffraction-pattern-analysis techni-
ques can drastically reduce the amount of in-
formation to be processed by an automatic ima-
ge-analysis system. Speeds are millions of times
faster than in image-digitizing systems. Diffrac-
tion patterns are formed by a relatively simple
laser-lens combination that reflects the frequen-
cy content of the image. The system provides
information about edge sharpness, object size,
etc., and allows for decisions at a rate of 100 to
10,000 per second. Applications include image-
quality assessment, transfer-function analysis,
and terrain classification.
For classification, the ROSA system (Jensen,
1973) has been used for cloud screening from
aerial photographs (Leighty and Lukes, 1974).
The detector is composed of 32 concentric near-
half-circle rings and 32 wedges. The data from
the detector array are transferred to a digital
computer for processing with pattern-recogni-
tion software. Preliminary work shows that
with a half-inch aperture only 3 out of 256 sam-
ple points were classified incorrectly.
Measurement with sensor arrays. - Measure-
ment accuracy of sensor arrays (O'Connor and
Chen, 1972) in a static model is limited by the
size of the individual array element. Conside-
rable improvement can be effected in dynamic-
vision theory. Due to involuntary eye move-
ments, coarse retinal receptors allow measure-
ments that are much finer than the smallest re-
ceptor. Applying this phenomenon, mechani-
cal or electronic perturbations over a sensor ar-
ray enabled positioning a light-point with a re-
solution 20 times finer than the size of an array
element. Possible applications of the system in-
clude detection of position, area, shape, and ve-
locity. It may also provide a substitute for film
in stellar cameras automatically yielding a real-
time readout of satellite and stellar coordinates.
Generation of digital elevation data
The AS-11B-X Plotter is an experimental
plotter for rapid and accurate extraction of to-
pographic information from frame and panora-
mic photographs (Scarano and Brumm, 1975).
It is designed specifically to generate digital ele-
vation data efficiently at very high rates and
accuracy. The system consists of a viewer, con-
trol computer, precision laser scanner in epipo-
lar planes, A/D conversion, digital storage and
correlation, and generation of multiple eleva-
tion profiles in a single pass. The data-collec-
tion rate in this system is expected to increase
to 10-50 times that of present systems. The dis-
tinguishing features of the system are :
1. Single scan of each resolution element.
2. Digital image storage and address modi-
fication (for scan shaping).
3. Epipolar scanning
4. Scan across and processing of multiple pro-
files
5. Mechanical scan of laser light spot
6. Multiple-bit digital correlation with pa-
rallel process minicomputer
7. Elevation computation in epipolar coor-
dinate system
8. Off-line computation of a fixed grid of
elevation points.
The AS-11 B-X system will serve as a test for
a production prototype of Advanced Compila-
tion Equipment (ACE).
Precise profiling on the AS-11B-1
The AS-11B-1, which originally contained
software to profile as a function of time or x, y
distance, has been modified to profile at extre-
mely precise rectilinear or geographic intervals
using the UNIVAC 1108 software (Sutterfield,
1972). The advantages of these modifications
are minimal postprocessing, nonredundancy of
data, convenient editing and correction, rapid
response, and minimizing of model-tie pro-
blems.
