Performance Analysis of a Cost-Effective Electret Condenser Microphone Directional Array

Humphreys, William M.; Gerhold, Carl H.; Zuckerwar, Allan J.; Herring, G. C.; Bartram, Scott M.

doi:10.2514/6.2003-3195

Cited by 6 publications

(3 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This was not studied for this project. Test results for a related Panasonic microphone capsule (model WM-60A) have been reported by Humphreys, et al 16 .…”

Section: B Microphonesmentioning

confidence: 81%

Aircraft Wake Vortex Measurements at Denver International Airport

Dougherty

Wang

Booth

et al. 2004

10th AIAA/CEAS Aeroacoustics Conference

View full text Add to dashboard Cite

Airport capacity is constrained, in part, by spacing requirements associated with the wake vortex hazard. NASA's Wake Vortex Avoidance Project has a goal to establish the feasibility of reducing this spacing while maintaining safety. Passive acoustic phased array sensors, if shown to have operational potential, may aid in this effort by detecting and tracking the vortices. During August/September 2003, NASA and the USDOT sponsored a wake acoustics test at the Denver International Airport. The central instrument of the test was a large microphone phased array. This paper describes the test in general terms and gives an overview of the array hardware. It outlines one of the analysis techniques that is being applied to the data and gives sample results. The technique is able to clearly resolve the wake vortices of landing aircraft and measure their separation, height, and sinking rate. These observations permit an indirect estimate of the vortex circulation. The array also provides visualization of the vortex evolution, including the Crow instability.

show abstract

“…This was not studied for this project. Test results for a related Panasonic microphone capsule (model WM-60A) have been reported by Humphreys, et al 16 .…”

Section: B Microphonesmentioning

confidence: 81%

Aircraft Wake Vortex Measurements at Denver International Airport

Dougherty

Wang

Booth

et al. 2004

10th AIAA/CEAS Aeroacoustics Conference

View full text Add to dashboard Cite

show abstract

“…The instrumentation needed for multiple microphone data logging has recently become broadly available, due to the decrease of the equipment cost of one microphone acquisition channel. The cost has been mostly reduced by the use of cheaper and easier to operate microphones, such as electret or mems microphones (Humphreys et al, 2003). Additionally, low cost digital microphone systems have recently become available (Kulka, 2011).…”

Section: Introductionmentioning

confidence: 99%

Simultaneous Calibration of Multiple Microphones for Both Phase and Amplitude in an Impedance Tube

Tóth¹,

Schram²

2015

Archives of Acoustics

View full text Add to dashboard Cite

This paper presents and compares microphone calibration methods for the simultaneous calibration of small electret microphones in a wave guide. The microphones are simultaneously calibrated to a reference microphone both in amplitude and phase. The calibration procedure is formulated on the basis of the damped plane wave propagation equation, from which the acoustics field along the wave guide is predicted, using several reference measurements. Different calibration models are presented and the methods were found to be sensitive to the formulation, as well as to the number of free parameters used during the reconstruction of the wave-field. The wave guide model based on five free parameters was found to be the preferred method for this type of calibration procedure.

show abstract

“…The authors have previously reported their experience with development of low-cost array technology based on commerciallyavailable electret condenser microphones. 9 The present study involved the fabrication and performance analysis of an array using commercially-available Micro-Electro-Mechanical System (MEMS) sensors which could easily be installed in closed reverberant wind tunnels. The objectives of the research study were:…”

Section: Introductionmentioning

confidence: 99%

Application of MEMS Microphone Array Technology to Airframe Noise Measurements

Humphreys

Shams

Graves

et al. 2005

11th AIAA/CEAS Aeroacoustics Conference

Self Cite

View full text Add to dashboard Cite

Current generation microphone directional array instrumentation is capable of extracting accurate noise source location and directivity data on a variety of aircraft components, resulting in significant gains in test productivity. However, with this gain in productivity has come the desire to install larger and more complex arrays in a variety of ground test facilities, creating new challenges for the designers of array systems. To overcome these challenges, a research study was initiated to identify and develop hardware and fabrication technologies which could be used to construct an array system exhibiting acceptable measurement performance but at much lower cost and with much simpler installation requirements. This paper describes an effort to fabricate a 128-sensor array using commercially available Micro-Electro-Mechanical System (MEMS) microphones. The MEMS array was used to acquire noise data for an isolated 26%-scale high-fidelity Boeing 777 landing gear in the Virginia Polytechnic Institute and State University Stability Tunnel across a range of Mach numbers. The overall performance of the array was excellent, and major noise sources were successfully identified from the measurements.

show abstract

Performance Analysis of a Cost-Effective Electret Condenser Microphone Directional Array

Abstract: Microphone directional array technology

Cited by 6 publications

References 12 publications

Aircraft Wake Vortex Measurements at Denver International Airport

Aircraft Wake Vortex Measurements at Denver International Airport

Simultaneous Calibration of Multiple Microphones for Both Phase and Amplitude in an Impedance Tube

Application of MEMS Microphone Array Technology to Airframe Noise Measurements

Contact Info

Product

Resources

About