Susceptibility Study of Audio Recording Devices to Electromagnetic Stimulations

Technical Report · Sat Feb 01 04:00:00 EST 2014

DOI:https://doi.org/10.2172/1204076· OSTI ID:1204076

Halligan, Matthew S. ^[1]; Beetner, Daryl G. ^[2]; Grant, Steven L. ^[2]

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1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
2. Missouri Univ. of Science and Technology, Rolla, MO (United States)

Little research has been performed to study how intentional electromagnetic signals may couple into recording devices. An electromagnetic susceptibility study was performed on an analog tape recorder, a digital video camera, a wired computer microphone, and a wireless microphone system to electromagnetic interference. Devices were subjected to electromagnetic stimulations in the frequency range of 1-990 MHz and field strengths up to 4.9 V/m. Carrier and message frequencies of the stimulation signals were swept, and the impacts of device orientation and antenna polarization were explored. Message signals coupled into all devices only when amplitude modulated signals were used as stimulation signals. Test conditions that produced maximum sensitivity were highly specific to each device. Only narrow carrier frequency ranges could be used for most devices to couple messages into recordings. A basic detection technique using cross-correlation demonstrated the need for messages to be as long as possible to maximize message detection and minimize detection error. Analysis suggests that detectable signals could be coupled to these recording devices under realistic ambient conditions.

• Research Organization: Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Missouri Univ. of Science and Technology, Rolla, MO (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 1204076
• Report Number(s): SAND--2014-0560; 498790
• Country of Publication: United States
• Language: English

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