Abstract
Active sonar systems interrogate their surroundings by transmitting pulses and listening for echoes. A classic approach to range estimation is pulse compression, where a high bandwidth pulse is transmitted and echoes are processed with matched filters. Matched filters optimize output SNR while range resolution is limited by the pulse bandwidth. Extensive research has focused on waveform design for sonar range resolution, often assuming matched filter receivers. However, relatively little research has explored alternative processing for active sonar receivers. Sharma and Buck (2011) proposed the variable resolution and detection receiver (VRDR), which smoothly adjusts range resolution between the matched filter and the inverse filter with one parameter, trading off detection gain for range resolution. In practice, the VRDR requires prior knowledge of the target and noise background to choose the best resolution and detection gain tradeoff. A new receiver is proposed to blend different VRDR receivers with different detection and resolution tradeoffs to adapt to the environment. The outputs of each VRDR receiver are weighted based on performance, using a mixture of experts' approach inspired by universal linear prediction [Singer and Feder, 1999] to implement the blending and minimize the regret of using a fixed individual VRDR filter. [Work supported by ONR.]