OPERATION OF THE UNAMACE
Using available technology, the com-
pilation operation requires manual atten-
tion at various points in the process. The
operator is used to recognize images cor-
responding to features in the terrain as a
step in establishing the geometry of the
photographs and to locate corresponding
images as an aid in difficult areas. The
UNAMACE is intended to make stereo
measurements automatically, with an opti-
mum coupling of the operator into the
measurement loop whenever necessary.
The procedure used in comparator and com-
pilation operations follows. It will be
appreciated that the comparator opera-
tions and associated computer calculations
to determine the camera parameters could
be performed on other equipments, freeing
the UNAMACE to perform the more de-
manding compilation operations. The de-
tailed measurement procedure depends upon
the nature of the available control in-
formation. The description is given in
terms of an operation in which sufficient
geodetic control is available to establish
the basic geometry.
The photo prints are examined first
to locate and measure, using a ruler,
the position of images of control points
whose geodetic positions are known. The
positions of additional pass points may be
located at the same time. The results of
this operation are prepared as paper tape
inputs for a UNAMACE comparator oper-
ation in which the measurements are up-
dated to the 4-micrometer rms accuracy
of the UNAMACE. Allfourofthe UNAMACE
tables are available for the measurements,
So as many as four diapositives may be
mounted on the tables at a given time.
The appropriate defining tapes, including
one which designates the order of mea-
surements, are entered into the computer.
The COMPARATOR indicator (on the con-
trol panel) lights, and the tables having
diapositives showing the first point move
to bring the images into the field of view.
The operator then switches the stereo
viewer to one or two of the tables show-
ing the point, depresses the keyboard
button designating the table to be positioned,
and centers the point on the reference
mark using the position control. As the
adjustment progresses, the operator re-
duces the control sensitivity by depressing
the divide-by-four key as required to
achieve the desired precise centering; this
can be repeated until a significant motion
of the ball is required for each 2-
micrometer least count. Once centering
is satisfactory, control is transferred via
the appropriate key to the second diapositive
containing the point, if any, and the pro-
cess is repeated. Final centering of a
selected image with respect to a second
image can be achieved automatically by
depressing the appropriate key; this fea-
ture is not used unless the area in the
field of view is level, because auto-
matic centering is on an average basis.
If there is a third image of the point
on another diapositive, the stereo viewer
is switched to observe the third image
and the process is repeated.
Once all of the images of a given point
have been measured, the operator uses the
keyboard to signal the equipment to move
to the next point. The results of the mea-
surements on the first set of points then are
transferred to a more permanent point in
the computer memory and, in addition,
typed out as a “hard copy” record of the
observations. The tables then move to
rough center on the second set of images,
and the overall process is repeated. When
all of the specified points on a given dia-
positive have been measured, the results
are output on paper tape; the table then
may be used for another diapositive in
the set. The process is continued in this
manner until all of the points of interest
have been measured.
The results of the measurements are
used by the computer to calculate the camera
orientation data. The BR-133has been pro-
grammed to make the required calculations
for single photographs and to extend this,
photograph by photograph, using a relative
orientation program. However, where there
