PROGRESS REPORT NO. 3

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A000700020027-4
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 12
• Document Creation Date: December 28, 2016
• Document Release Date: April 1, 2002
• Sequence Number: 27
• Publication Date: April 18, 1966
• Content Type: REPORT

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STAT
Progress Report No. 3
Report Period: 19 March 1966 to 18 April 1966
Project Title: Gems Development (continuation)
PROJECT IDENTIFICATION
Contractor's Project No. . is, . . . . . .SPO 27203
Customer's Project No. . . . . . . . . .99740-6
STAT
FISCAL DATA
Type of Contract
Total Contract Price
Scheduled Completion Date
Percent of Total Funds Expended
Percent of Work Completed
Declass Review by
NIMA/DOD
30 June 1967
10.47. as of 25 4pr., 1966
10.4% as of 25 W r. 1966
STAT
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Objective of Project
The principal objective of this project is to determine how well
the image quality of mission photography can be assessed by means of Gems.
In order to accomplish this objective, psychological tests shall be performed
wherein photographic images of known quality (Gems) are compared to mission
photography. In fulfillment of this objective, a number of subtasks are being
undertaken. These subtaska consist in the refinement of existing Gem making
techniques, the study of alternate techniques, the study of Gems viewing
equipment, and the preparation of Gem sets in large numbers.
Status of Overall Project
During the third month of this program, the expansion of the
photographic facility was completed with the exception of the installation
of sinks and cabinets in the second darkroom. This portion of the expansion
has been delayed approximately three (3) weeks because of procurement dif-
ficulties. In the area of special equipment essential to the production of
Gems, good progress has been made. A modification to the light source assembly
of the breadboard Gems maker has been completed and tested. The tests demon-
strate that much shorter exposure times will now be required in the preparation
of Gems. This design improvement is now being implemented in a second Gems
maker. This equipment together with the expanded photographic facility will
provide the means to satisfy all of the Gems production requirements on this
program.
The progress on the various subtasks is given below. In most
instances, the work on each subtask has either just begun or is about to be
started. One notable exception is the analysis of physical limitations in-
herent in the Gems making procedure. The results of this analysis which
take into account near field effects are given in this report.
Work Completed During Report Period
a) Equipment Modification
The modification to the source assembly of the Gems maker affected
an even greater reduction in exposure time then had been anticipated. Tests
with positive type film (blue sensitive) show a reduction in exposure time
by a factor of approximately 30. It appears that the bromine cycle lamp
is spectrally more efficient then the tungsten source in the blue region
of the spectrum. This spectral effeciency probably explains why exposure
times can be reduced by a factor of 30 as apposed to the factor of 3 that
had been expected. In the exposure of negative type film, we should not
expect an equally favorable result. However, a tenfold reduction in exposure
time might not be unreasonable. A comparative analysis of the two exposure
conditions is given in Figure 1 attached. The sensitometric curves pro-
duced in each case are the result of equivalent exposure times and near
identical processing.
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b) Near Field Effects in Gem Making
In the preparation of Gems by the modified printing technique,
a separation is introduced between the transparency and the film being
exposed. Under these conditions, the illumination of the transparency
can give rise to diffraction images in the film plane. To date, these
effects have been neglected in the prediction of the image formed in the
film plane.
The formation of diffraction images in the film plane has been
examined analytically. In this analysis, a perfect knife edge image is
assumed to exist in the plane of the transparency. Furthermore, the source
which illuminates this transparency is assumed to have a Gaussian distribution
in intensity. At this point, the formation of the image in the film plane
is determined according to two mechanisms. (1) - The rectilinear propagation
of the source distribution and (2) the near field diffraction image. This
analysis was carried out for several spacings of film and transparency such
that the quality of the image (neglecting near field effects) plane was
expected to progress from a cutoff frequency of 50 cycles per mm to 400
cycles per mm. The results of this analysis are given in Figures 2 through
9. In each of the cases evaluated, the Gaussian edge-image predicted
on the assumption of no near field effects is given. Also in each case,
a second edge image is shown which image includes the effects of near field
diffraction.
The cases evaluated provide a good insight into the importance of
near field effects. It is apparent in the case of the 50 cycle per nine
condition that near field effects are negligible. On the other hand, near
field effects are clearly the dominant factor in the formation of images
in the range of 200 to 400 cycles per nmm. The spatial frequency at which
near field effects limit the usefulness of this Gems making technique is not
precisely identified by this analysis, but there is a good indication that
the technique should prove useful out to approximately 100 cycles per mm.
In that case, Figure 3, the near field effects are apparent but are not
dominant. In practice, the near field effects would never be as strong as
this analysis indicates since the transparencies from which Gems are pro-
duced are not in themselves knife edge images..
c) Psychophysical Testier
The subcontract in the area of psychophysical testing has been
established. A preliminary meeting was held at the customer's facility
during the week of 28 March. It is anticipated that a second meeting will
occur again at_ the customer's facility during the week of 25 April. The
objective of this second meeting will be the establishment of the specifications
for a Gems Set to be employed in the psychophysical study. Once these speci-
fications are agreed upon, the schedule for preparing the required Gems material
will be re-exaniined.
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3 -
An American Optical Split Field Microscope Comparator has been
ordered with delivery scheduled for 15 June. It is our intention to perform
a design study on the r,equire.;ients of a Gems Viewer built around this device.
This subtask has been assigned to as lead en inter. STATINTL
T. ork for Next Period
The specific activity for the next period will includ
a) Completion of the photographic facility and all
associated equipment.
b) Specification of Gems for Psychophysical Testing.
c) Planning of Gems Viewer Study.
d) Initiation of study on alternate Gems making
technique.
STAT
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