Passive Remote Acoustic Sensing in Aerospace Environments

Abstract

Video imagery of exo-atmospheric aerospace phenomena such as rocket ascents, stage separations and space-vehicle re-entry is an important tool for supporting engineering and outreach objectives. But recording the sounds associated with these distant or otherwise inaccessible environments is difficult at best and usually not practical. The Remote Acoustic Sensor (RAS) is a new type of microphone that separates the acoustic transducer into spatially separated components and can achieve this result. One component of RAS is a naturally formed in situ acoustic modulator and the other is a remote readout device. These components are passively coupled over long distances at the speed of light by naturally occurring ambient electromagnetic fields. Stereophonic and multi-channel sound can be captured by RAS, and when combined with high-definition video it can provide a cinemalike immersive viewing experience. Examples in this paper include visually and aurally recorded scenes ranging from exo-atmospheric rocket events at >100 km observing distances to free swimming protozoa within micro-aquatic worlds. We are currently extending RAS technology to small ruggedized camera systems suitable for use onboard rockets, spacecraft and other high-performance aerospace vehicles. Feasible approaches to space-based observations of terrestrial sounds and as an element of planetary remote sensing are also discussed, along with some early experimental results.

Graphene-Based Acousto-Optic Sensors with Vibrating Resonance Energy Transfer and Applications

“…Long range acoustical sensors are utilized for passive sensing of vibrations, flutter, atmospheric turbulence, and terrestrial and planetary sounds remotely [21]. Utilization of reflective …”