MATLAB Exercises with COMSOL Data - Introduction to Imaging from Scattered Fields - page 218

2. Use ewald in MATLAB to generate Ewald circles for a target consist-
ing of one circle (Choice 0) and two circles (Choice 1). Use any valid
permittivity and a minimum of 12 sources and 120 receivers. For each
target save a 2-D output image of the combined Ewald circles. How are
these images similar? How are these images different? Please discuss
your observations and speculate on reasons for both the similarities
and differences.
3. Repeat the procedure in Exercise 1 for one square (Choice 2) and two
squares (Choice 3). Compare the resulting images obtained here with
the images obtained in Exercise 1. Discuss similarities and differ-
ences and reasons for them.
4. Use ewald in MATLAB to generate Ewald circles for two triangles
(Choice 5) using 4 sources and 360 receivers. Do this twice, once for a
target permittivity of 1.1 and again for a target permittivity of 1.9. Be
sure and show the individual Ewald circles for each source. For each
scenario save the individual Ewald circle for Source #2. Compare the
images for each Ewald circle. Describe the differences and discuss
why you think they are so different.
born exercises
1. Use born in MATLAB to generate Born approximation reconstructions
for various targets. Do this several times varying the target, the per-
mittivity, the number of sources, and the number of receivers. Discuss
your observations for the various scenarios and give some speculation
for reasons for the variations observed.
2. Use born in MATLAB to generate Born approximation reconstruc-
tions for a circle (Choice 0) using 36 sources and 360 receivers. Also,
set the image maximum dimension to 0.25 for each case. Do this three
times for a target permittivity of 1.1, 1.5, and 1.9. For each scenario
save the Born images generated. Compare the images for each Born
reconstruction and discuss the differences. Please speculate as to the
reason for these differences.
3. Use born in MATLAB to generate Born approximation reconstruc-
tions for any target consisting of two objects (Choices 1, 3, or 5) using
any valid permittivity and a minimum of 6 sources and 120 receivers.
Be sure and show the individual Born reconstructions for each source.
Please discuss your observations for the individual Born reconstruc-
tions for each source and speculate on their relationship to the Born
of the combined sources.
4. Use born in MATLAB to generate Born approximation reconstruc-
tions for two circles (Choice 1) using a minimum of 12 sources and 120
receivers. Do this twice, once for a target permittivity of 1.1 and again
for 1.9. For each scenario save the individual Born reconstruction for
Source #12. Compare the images for each reconstruction. Describe the
differences and discuss why you think they are so different.
Cepstrum exercises
1. Use Cepstrum in MATLAB to generate Born and Cepstrum recon-
structions for various targets. Do this several times varying the
target, the permittivity, the number of sources, and the number of