This paper describes an approach to combining range data from both a set of sonar sensors as well as from a directional laser range finder to efficiently take advantage of the characteristics of both types of devices when exploring and mapping unknown worlds. We call our approach “just in time sensing” because it uses the more accurate but constrained laser range sensor only as needed, based up...

Advances in high frequency sonar have provided increasing resolution of sea bottom objects, providing higher fidelity sonar data for automated target recognition tools. Here we investigate if advanced techniques in the field of visual object recognition and machine learning can be applied to classify mine-like objects from such sonar data. In particular, we investigate if the recently popular S...

This paper explores the intersection of two fields of research: autonomous underwater vehicles (AUVs), and archaeology in the deep sea. Archaeology in the deep sea poses a range of difficult, interesting problems for autonomous underwater vehicles. These include broad area sonar searches, target identification, and precision survey. Broad area sonar searches for archaeology have requirements si...

Abstract: In this work an unsupervised Sonar (Sound navigation and ranging) images segmentation is proposed. Due to the textural nature of the Sonar images, a band-pass filtering that takes into account the local spatial frequency of these images is proposed. Sonar image is passed through a bank of Gabor filters and the filtered images that possess a significant component of the original image ...

This paper describes an approach to combining range data from both a set of sonar sensors as well as from a directional laser range nder to eeciently take advantage of the characteristics of both types of devices when exploring and mapping unknown worlds. We call our approach \just in time sensing" because it uses the more accurate but constrained laser range sensor only as needed, based upon a...

A new approach to rejecting interference between sonar systems is presented in this paper. The approach is based on identifying a transmitter by sending a double pulse with known separation. Using simple delayed pulse subtraction, a sonar receiver can test echo pulses quickly and simply for acceptance. This approach is implemented on a sonar system that is capable of accurately tracking objects...

We present an algorithm to distinguish several types of brick walls, picket fences, and hedges based on the analysis of backscattered sonar echoes. The echo data are acquired by a mobile robot with a single-transducer 50 kHz pulse-echo sonar computer-controlled scanning system packaged as its sensor head. For several locations along a wall, fence, or hedge, a fan of backscatter sonar echoes is ...

In order to the meet the requirements for the timeliness and the large data volume of the data transmission of the towed linear array sonar system, a kind of data recording system based on PCI is designed. In the aspect of hardware, the system employs the scheme combining PCI9054 efficient DMA transmission technology and the external-expansion large-capacity FIFO to realize the high-speed and c...

In response to sonar-guided attacking bats, some tiger moths make ultrasonic clicks of their own. The lepidopteran sounds have previously been shown to alert bats to some moths' toxic chemistry and also to startle bats unaccustomed to sonic prey. The moth sounds could also interfere with, or "jam," bat sonar, but evidence for such jamming has been inconclusive. Using ultrasonic recording and hi...

Title of dissertation: ADAPTIVE FLIGHT AND ECHOLOCATION BEHAVIOR IN BATS Benjamin Mather Falk, Doctor of Philosophy, 2015 Dissertation directed by: Professor Cynthia F. Moss Program in Neuroscience and Cognitive Science Bats use sonar to identify and localize objects as they fly and navigate in the dark. They actively adjust the timing, intensity, and frequency content of their sonar signals in...