From Event: SPIE Defense + Commercial Sensing, 2021
Hobbyist electronics have greatly improved in both quality and capability over the past several years. It is now possible to solve computationally challenging problems with equipment costing less than a few hundred US Dollars. Both of the datalogger concepts presented in this work leverage this improvement by using off-the-shelf technology to replace what could previously only be done with expensive custom hardware. The processors used in these concepts, the Teensy 4.0 Audio Adapter and the CTAG BEAST, were originally designed for musicians who require the ability to manipulate multiple channels of audio simultaneously. This capability, however, also enables the construction of dataloggers capable of recording perfectly synchronized multi-channel audio – a requirement for passive phased sonar arrays. Each datalogger carries the additional benefit of low power consumption, permitting the array to be deployed for several hours before requiring recovery. Future versions of the dataloggers are expected to have mission durations comparable to existing commercial systems. This paper follows the development process of both of these concepts and compares each of their performance. The first concept, the Teensy, consists of two Teensy 4.0 control boards, each sandwiched between two Teensy Audio Adapters. This assembly is capable of recording up to eight channels of audio in near perfect sync. The second concept, the BEAST, consists of a BeagleBone Black single board computer augmented with a CTAG BEAST cape. This system is capable of recording eight channels of perfectly synchronized audio. Both of these systems were tested in the field with a four-element co-prime sonar array. The data is analyzed and the results of the comparison are presented in this work. Finally, some operational recommendations and possibilities for improvement are also discussed.
© (12 April 2021) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Chloe Alex Schaff, Yanjun Li, Bing Ouyang, Casey Den Ouden, Tongdi Zhou, and Fauzia Ahmad, "Development of a low-cost subsea datalogger for passive phased sonar arrays," Proc. SPIE 11730, Big Data III: Learning, Analytics, and Applications, 1173008 (Presented at SPIE Defense + Commercial Sensing: 12 April 2021; Published: 12 April 2021); https://doi.org/10.1117/12.2587935.