THIRD LETTER REPORT ON EVALUATION (U) (13 JANUARY 1966 TO 14 FEBRUARY 1966)

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A002900030015-2
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 3
• Document Creation Date: December 28, 2016
• Document Release Date: June 19, 2002
• Sequence Number: 15
• Publication Date: February 14, 1966
• Content Type: REPORT

Approved For Release
2002/07T~~ - 4T -
THIRD LETTER REPORT ON EVALUATION (U)
(13 January 1966 to 14 February 1966)
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DECLASS REVIEW by NIMA/DOD
14? February 1966
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Approved For Release 2002/07/10 : CIA-RDP78B04747A42900030015-2
 Approved Foelease 2002/07/10 : CIA-RDP78B047Ui4002900030015-2
THIRD LETTER REPORT ON EVALUATION (U)
I. Work for Reporting Period
During the past month work has continued" on completing two-pinhole inter-
ferometer to measure the degree of coherence in the object plane. We are now
experimenting to determine whether fiber optics, probes having a fixed output spacing
and variable separation input spacing will enable us to measure the degree of
coherence at various . pinhole spacings and thus avoid the complexities of determining
the visibility of very higli spatial frequency fringes. This also provides flexibility
in locating the fringe detector unit outside the confines of the object plane region.
The fabrication of the 35mm 200' magazine adapter for use at the image plane has
been completed. We are now using it to obtain optimum focus position, exposure
data and paraxial resolution for both the He-Ne and Na sources. The
people arrived on 7 February to realign the optics but have not yet completed their
work due to lack of a proper alignment target which they are awaiting delivery on
The theoretical work completed during the past month includes the following.
A calculation of the partially, coherent images of one dimensional three bar targets
of various contrasts has now been completed to the point where it is ready for final
numerical evaluation on the 7090 computer. The computer program is now being
written.
It has been determined that the partially coherent imaging technique will be
applicable to the problem of measuring the coherence interval of the object illumination.
It will be necessary to stop down the first imaging lens so that the system will closely
approximate a diffraction limited system. This imaging work will also be done on
axis.
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II. Work for Next Period
The calculation and recording of images of low contrast objects will be
continued. A series of low contrast objects, (edges and three bar targets) will
be examined using both the sodium and laser sources to create varying degrees
of spatial coherence in the object plane. For this low contrast series the system
should act as a linear system, independent of the degree of coherence of the
r r:
illumination. ? The series'will be repeated for increasing target contrasts and
the shift from a linear to a non-linear imaging.system examined and evaluated.
During this next reporting period
representatives will return 25X1
to realign the enlarger and thus obtain better symmetry of aberrations in the image
plane. For our present work..this lack of symmetry should not affect our paraxial.
imaging experiments.
III. Visits to Contractor
During this reporting period we made no visits to the contractor. Messrs.
spent one day (7 February) at
T/O for preliminary alignment work on the enlarger. They expect to return within
2 weeks to complete their alignment work.
N. Changes in Personnel
V~ft
V. Progress of Work
has been added to the program staff.
As of this reporting date approximately 1.6% of the work program has been
completed and 19% of the contract funds have been expended. Now that the enlarger
checkout, camera back modifications, and computer programming are essentially
completed we expect that the completion rate will be substantially increased. No
delays in completing the contracted program within funds or within specified completion
datos are anticipated.
Approved For Release 2002/07/10 : CIA-RDP78B04747A902900030015-2