MATLAB Exercises with COMSOL Data - Introduction to Imaging from Scattered Fields - page 220

Multiplier value to 0.1, 1 (default), and 10. Observe and compare the
effects of varying the multiplier on each reconstruction method. Does
it affect each method the same? Why or why not? What seems to be the
optimal value for this multiplier for each case?
pdFt exercises
1. Use pdFt in MATLAB to generate PDFT, Born and Cepstrum recon-
structions for a square target (Choice 2) using a permittivity of 1.2
and a minimum of 12 sources and 120 receivers. For the prior use a
square shape with the default widths. (Set maximum image scale to
0.5 m for better results.) How does the reconstructed image using the
PDFT method compare with the Born reconstruction? Which method
performs the best? Why do you think this is?
2. Repeat the process described in the previous example applying the
PDFT method described, and then once again without using the PDFT
method. This time compare the performance of the Cepstrum method
outputs for each case. How do these reconstructed images compare?
Discuss your observations for each Cepstrum reconstruction paying
special attention to the scales. Which method performs the best? Why
do you think this is?
3. Repeat the process described in the previous example applying the
PDFT method described, with the exception of setting the prior widths
equal to 0.06. Please discuss your observations for the PDFT and the
Cepstrum reconstructions. How does this affect the results? Why do
you think this is?
4. Repeat the process described in the previous example applying the
PDFT method described, with the exception of setting the prior offsets
equal to 0.1. Discuss your observations for the PDFT and the Cepstrum
reconstructions. How does this affect the results? Why do you think
this is?
5. Use pdFt in MATLAB to generate PDFT, Born, and Cepstrum recon-
structions for the square and circle target (Choice 4) using a permit-
tivity of 1.2 and a minimum of 12 sources and 120 receivers. For the
prior, use a two shape combination of a circle and a square that are
centered on the appropriate corresponding target location. The prior
shape sizes should be slightly bigger than the target dimensions. Save
images of the reconstructed images and the prior shapes for review.
Did the use of the prior improve the reconstructed images?
6. Use pdFt in MATLAB to generate PDFT, Born, and Cepstrum recon-
structions for any target consisting of two objects (Choice 1, 3, or 5)
using any valid permittivity and a minimum of 6 sources and 120
receivers. Run the reconstructions twice, using PDFTs as input to
the Cepstrum method and again using only the Born as inputs to the
Cepstrum method. Be sure to show the individual Born and Cepstrum
reconstructions for each source. Discuss your observations for the
individual Born and Cepstrum reconstructions for each source for
both methods. What are some of the differences between using the two
inputs? Which method performs the best? Why do you think this is?
7. Use pdFt in MATLAB to generate PDFT, Born, and Cepstrum recon-
structions for the target set consisting of a triangle, a square, and a circle