Assume you have to use the array from the previous problem in an isovelocity (1500 m/s), shallow water environment with water depth 120 m, and with an infinitely rigid bottom. Assume you are towing the array at 60-m depth, and that the source is at 60-m depth as well.
a. For a 10-Hz source at 45ı bearing, and 80-km range, write an algorithm for computing the field on the elements of the array in terms of a modal expansion.
b. Use the linear beamformer developed for problem 10.1 to compute the response.
c. Discuss the features of the beamformer response and provide a physical explanation for the performance.
d. How do you suggest to modify the beamformer to yield a correct bearing estimate?
e. Implement the modification and discuss the performance.