Page 443 - Introduction to Information Optics

428 7. Pattern Recognition with Optics

7.22 Using a colinear RGB coherent illumination:
(a) Sketch a Fourier-domain polychromatic processor by which the
multitarget set can be detected.
(b) If temporal spatial filters are being encoded with the Vander Lugt
interferometric technique, sketch and explain the procedure for how
those filters can be synthesized.
(c) By proper implementation of the filters of part (b) in the Fourier
domain of part (a), show that polychromatic target detection can be
indeed obtained at the output plane.
7.23 To synthesize a set of temporal holograms (i.e., matched filters) for
polychromatic pattern detection in a VLC, one can use spectral disper-
sion with an input-phase grating. Assume the spatial-frequency limit of
the polychromatic target is 10 hz per min, focal length of the transform
lenses is 300 mm, and wavelengths of the RGB light source are 600 nm,
550 nm, and 450 nm, respectively.
(a) Calculate the sampling frequency requirement of the phase grating.
(b) Sketch the interferometric setup for the filter synthesis.
(c) What would be the spatial-carrier frequency of the set of matched
filters?
(d) Evaluate the output polychromatic correlation distribution.
7.24 Assume a color LCTV is used at the input plane of a VLC; the pixel
structure is shown in Fig. 7.24.
(a) Sketch a diagram to show that a set of RGB matched filters can be
interferometrically synthesized at the Fourier domain.
(b) Evaluate the recorded matched filters.
(c) Evaluate the output polychromatic correlation distribution.
7.25 Refer to LCTV panel of Fig. 7.24.
(a) Show that isolated RGB-JTPS can be captured by a color CCD
array detector.
(b) If one replicates the RGB-JTPS in the LCTV panel for correlation
operation, show that high efficient polychromatic correlation detec-
tion can be obtained.
(c) If we assume that the RGB-JTPS is replicated into N x N arrays,
what would be its correlation efficiency?
(d) Is it possible to use partial-spatial-coherent RGB light for JTC
correlation detection of the replicated JTPS arrays of part (c)? What
would be the spatial-coherent requirement of the light source?
(e) Comment on the correlation peak intensity and noise performance by
using a strictly coherent and a partial-spatial-coherent source.
7.26 Refer to the autonomous target tracking of Sec. 7.4.1. The location of the
correlation peak as a function of the target's translation in the x direction
is plotted in Fig. 7.63(a). Considering the limited resolution of the array
detector, find the minimum speed of the target that can be properly