Novel Dynamic Paradigms for Wave Sensing Inspired by Bat Biosonar

目前的声纳和雷达技术所遵循的方法似乎与蝙蝠生物声纳所采用的方法有着根本的不同：工程系统依赖于大量的发射器和接收器，每个发射器和接收器都有相当简单的特征，而蝙蝠生物声纳只需要非常少量的复杂的发射器和接收器。蝙蝠发出超声波脉冲，并使用挡板形状接收回声，可以将其与扩音器和喇叭天线进行近似比较。然而，这些形状不仅在几何上比技术上的同类复杂得多，而且它们还具有独特的动态维度，因为它们可以在类似于动物超声波脉冲持续时间的时间尺度上改变形状。与此同时，在处理结构丰富的自然环境方面，蝙蝠生物声纳似乎比工程系统优越得多。因此，了解动态维度在蝙蝠生物声呐中所起的作用，可能会导致新的动态传感范式，从而提高声呐、雷达和相关技术传感模式的性能。本研究将在一个仿生声呐原型中再现和调查生物声呐系统中某些蝙蝠物种的动态特征。要测试的主要潜在假设是，这些挡板形状的变形为这种生物传感系统增加了一个动态维度，可用于(i)扩大系统对感官信息的一般编码能力，（ii）增强某些显著特征的编码，（iii）使系统适应不同的传感场景。如果是这样的话，蝙蝠生物声纳的不同寻常的动态尺寸可能是蝙蝠在复杂的自然环境中满足导航感官需求的卓越能力背后的关键因素，这种能力是基于非常简约的感官输入。这一假设将通过构建一个仿生声纳系统来研究，该系统将采用挡板形状进行发射和接收，可以与各自的衍射过程同步改变其形状。仿生传感系统将用于研究自然生物声纳传感任务中感觉信息的动态编码。这些实验结果将使用数值模拟和信息论方法来处理自然生物声纳场景的随机性和由此产生的回波信号。

Current technical sonar and radar technology follows an approach that appears to be fundamentally different from what can be observed in bat biosonar: Whereas engineered systems rely on large numbers of emitter and receiver elements that each have rather simple characteristics, bat biosonar operates with a very small number of intricate emitters and receivers. Bats emit their ultrasonic pulses and receive the echoes using baffle shapes that can be compared to megaphones and horn antennas to a first approximation. However, these shapes are not only geometrically much more complicated than their technical peers, they can also have a unique dynamic dimension in that they change their shapes on time scales that are similar to the duration of the animals' ultrasonic pulses. At the same time, bat biosonar appears to be far superior to engineered systems in dealing with structure-rich natural environments. Hence, developing an understanding of the role that the dynamic dimension plays in bat biosonar could lead to novel dynamic sensing paradigms that could improve the performance of sonar, radar, and related technical sensing modalities.This research will reproduce and investigate dynamic features seen in biosonar the biosonar system of certain bat species in a biomimetic prototype sonar. The principal underlying hypotheses to be tested is that the deformations of these baffle shapes add a dynamic dimension to this biological sensing system that could be used to (i) enlarge the system's general coding capacity for sensory information, (ii) enhance the encoding of certain salient features, (iii) adapt the system to different sensing scenarios. If this is the case, the unusual dynamic dimension of bat biosonar could be a key factor behind the superior ability of bats to meet the sensory needs for navigation in complex natural environments based on a very parsimonious sensory input. This hypothesis will be investigated by constructing a biomimetic sonar system that will employ baffle shape for emission as well as reception that can change their shapes in synchrony with the respective diffraction processes. The biomimetic sensory system will be used to investigate the dynamic encoding of sensory information in natural biosonar sensing tasks. The results of these experiments will be analyzed using numerical simulations and information-theoretic methods to deal with the random nature of natural biosonar scenes and the resulting echo signals.