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METHODS OF TESTING
PRODUCTION TESTING
OTF IN RESEARCH
OTF IN LENS DESIGN
SYSTEM TESTING USING MTF
WRIGHT-PATTERSON AFB AFAL/RWF EVALUTION OF AERIAL IMAGERY--
GLIATTI
WELCH AND CORBETT EVALUATION OF SPACE IMAGERY
REPORTS FROM NATIONS
APPLICATION TO QUALITY CONTROL
CURRENT STUDIES
SIGNAL TO NOISE
PHASE
COHERANCE
CASCADING
INTERFEROMETRIC METHODS
OTHER APPLICATIONS
RECOMMENDATIONS AND PROPOSALS
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4. WORKING GROUP ACTIVITY
Phase Transfer Function (Brock)
It is always advisable to consider the problems of phase when
OTF and MTF are being used in either development or quality assurance
applications. There are papers by Shack and Lamberts explaining
the significance of phase and a review of the subject is presented
here by Brock.
4.1.1 The Significance of the Phase Transfer Function ( o
4.1.1.1 Description: In the common one-dimensional analysis, the
Optical Transfer Function (OTF) is the Fourier Transform of the
line spread function. The mathematical transformation yields two
parts, the Modulation Transfer Function (MTF) and the Phase Transfer
Function (PTF). To appreciate the physical significance of these,
consider that in applying the OTF to the imagery of an object,
the latter must first be transformed into its hypothetical component
sinewaves. For example, a squarewave is equivalent to a fundamental
sinewave at the squarewave frequency, plus the odd harmonics in
a specific phase relationship. In a perfect image, the squarewave
would be built up by the sum of frequencies
4/1 IN + 1/3 (3N) + 1/7 (7N) + etc.---- ]
where 1/3 etc., represent the relative amplitudes of the harmonics
and N is the fundamental frequency. The phasing is such that at