A noise analysis is conducted on an interferometric sensor employed in the study of underwater acoustic noise. Primary emphasis is placed on finding the output Signal to Noise Ratio of the sensor.
Once the initial problem of the type of noise is established, the analysis proceeds along fairly classical lines. Field equations establish the signal reaching the director. Linear filter analysis establishes the nature of the spectrum after passing through a lowpass filter. Finally, second moment theory is used to derive expressions for the outpud Signal to Noise Ratio.
It is noted that the random ocean noise introduced to the filter randomly phase modulates the signal. This noise seriously affects the value of the Signal to Noise Ratio. It is hoped that the spectral analysis presented will assist designers in minimizing the noise input to the system. The sensor is more sensitive to low frequency acoustic signals such as would be encountered from distant ocean vessels. Regardless of the noise spectral density, these sensors can be used with relative confidence as under water Acoustic Hydrophones.
Master of Science (M.S.)
College of Engineering
Length of Campus-only Access
Masters Thesis (Open Access)
Phillips, Mark, "Noise in Interferometric Sensors" (1986). Retrospective Theses and Dissertations. 4938.