Abstract
Several authors previously found that echolocating animals aim their sonar beam to place the target of interest slightly off the main beam axis. Analysis found the animals' beam aiming strategy maximized the Fisher Information (FI) about the target bearing encoded in the frequency spectrum of the received echoes by the transmitter's frequency dependent beampatterns. This thesis reverses the focus from analysis to synthesis. We present design methods to maximize the FI of the bearing estimate at a desired angle using linear frequency modulated waveforms transmitted by a continuous line source transducer. If the bandwidth of the transmitted chirp is sufficiently small relative to the center frequency, the angle maximizing the bearing FI is solely determined by the center frequency. The center frequency is shown to place a null in the transducer's beampattern at the target's angular location or, equivalently, the target's angular location places a null in the received echo at the corresponding center frequency. This maximizes the waveform's relative variation resulting in favorable auto-correlation properties. Increasing bandwidth increases robustness to target bearing mismatch at the cost of decreased precision at the target's true angular location.