Remote Acoustic Sensing

Remote Acoustic Sensing (RAS) is a patented / patent pending technology that can be used to listen to sounds that are otherwise unobservable.

Listening to an exoatmospheric SpaceX Falcon 9 stage separation sequence from 70+ miles away !

Yes, protozoa and other microscopic fauna "talk".

A popular article about RAS is: "Listening for Alien Life: Could New Tech Detect Microbe Movements?", by Leonard David,'s Space Insider Columnist (copy)

A more detailed technical paper is: "Light to Sound: The Remote Acoustic Sensing Satellite (RASSat)" that was recently presented at the Smallsat 2016 conference in Logan, Utah.

Paper abstract: “In space, no one can hear you scream,” as the tagline from the sci-fi film Aliens goes. But what if there were a way of “hearing” in space, moving in-space video from the Silent Era to a more contemporary cinematic experience? How could this capability be applied to shape future spacecraft and mission designs? Such a capability can be effectively incorporated into a 3U CubeSat using a measurement technique called Remote Acoustic Sensing (RAS). “RASSat” uses advanced optical sensors to view and recover audio from distant objects that have weak optical modulations produced by local sound and vibration sources; the modulated light sources and the RAS sensor are passively coupled at the speed of light, yielding a variety of interesting sounds across the entire human auditory range. RAS field demonstrations and analyses have identified and characterized terrestrial sound sources observable from LEO, along with associated acousto-optic modulation mechanisms. RASSat sensitivity is such that both day and night strong, easily detectable terrestrial acousto-optic emitters abound, and applications to Space Situational Awareness and planetary exploration are also evident. This paper provides an overview of the RAS measurement technique and recent terrestrial demonstrations, and highlights key RASSat design features, performance capabilities and applications.

RAS technical papers:

Slater, D., S. Kozacik, E. Kelmelis "Photo-acoustic and Video-acoustic Methods for Remote Sensing of Distant Sound Sources", SPIE Long Range Imaging II, Anaheim, CA, 2017

Slater, D., R Ridenoure, D. Klumpar, J. Carrico, M. Jah, ”Light to Sound: The Remote Acoustic Sensing Satellite (RASSat)”, 30th Annual AIAA/USU Conference on Small Satellites, Logan, Utah, 2016

Slater, D., R Ridenoure, "Passive Remote Acoustic Sensing in Aerospace Environments",  AIAA SPACE Forum 2015, Pasadena, CA 2015

Slater, D., "A Telescopic Cinema Sound Camera for Observing High Altitude Aerospace Vehicles", Proc. SPIE 9227, Unconventional Imaging and Wavefront Sensing 2014, 92270A, September 18, 2014

Slater, D., Shaw, S., M.D., "Remote Sensing with Passive Specular Probes", Proc. SPIE. 6709, Free-Space Laser Communications VII, 67090W, September 13, 2007

Slater, D., "Passive Long Range Acousto-optic Sensor", Proc. SPIE. 6304, Free-Space Laser Communications VI, 63040E, August 31, 2006

RAS patents:

Slater, D., "Electrosound camera", US patent: 9,823,348

Slater, D., "Electrosound camera", US patent: 9,817,118

Slater, D., "Electrosound camera", US patent: 9,709,671

Slater, D., "Passive Long Range Acoustic Sensor", US patent: 7,551,519

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Copyright 2017 by Dan Slater