This paper discusses comparisons made between two ground-based outdoor microphone configurations. The first consists of an inverted microphone placed above a convex circular plate and covered by a large dome windscreen. The second, updated, configuration is similar but has a thicker windscreen and a thinner ground plate. Both were subjected to laboratory testing where their responses to sound were recorded at several different elevation and azimuthal angles. At almost all shown elevation angles, both configurations recorded levels that were within ±3 dB of a baseline measurement between 50 Hz – 20 kHz. At all shown azimuthal angles and over the same frequency range, both configurations recorded levels within ±2 dB of the levels reported at an azimuthal angle of 0°, with the updated configuration having less variation. Both were also subjected to wind noise testing, where the updated configuration demonstrated superior wind noise rejection at low frequencies. The conclusion is that both are suitable for outdoor acoustical measurements and that the updated configuration is superior, especially when measuring low-frequency noise. This the physical and differences between COUGAR and COUGARxt. the physical of the are by a description of the testing which included and The conclusion from laboratory testing is that and that has a flatter The conclusion drawn from the field testing is that COUGARxt further improves on COUGAR’s noise
[1]
Vincent P. Blandeau,et al.
A New Plate Design to Improve the Accuracy of Aircraft Exterior Noise Measurements on the Ground
,
2021,
AIAA AVIATION 2021 FORUM.
[2]
Michael M. James,et al.
Examining wind noise reduction effects of windscreens and microphone elevation in outdoor acoustical measurements
,
2020,
The Journal of the Acoustical Society of America.
[3]
S. Mcinerny,et al.
Commercial Space Operations Noise and Sonic Boom Measurements
,
2020
.
[4]
Frank S. Mobley.
Aircraft Characterization with Ground Boards and Inverted microphones
,
2019,
25th AIAA/CEAS Aeroacoustics Conference.
[5]
Vincent P. Blandeau,et al.
Acoustic behaviour of ground plates for aircraft noise flight tests
,
2018,
2018 AIAA/CEAS Aeroacoustics Conference.
[6]
G. P. V. D. Berg.
Wind-induced noise in a screened microphone
,
2006
.
[7]
Belur N. Shivashankara,et al.
Ground plane microphone for measurement of aircraft flyover noise
,
1987
.
[8]
W. L. Willshire,et al.
Investigation of effects of microphone position and orientation on near-ground noise measurements
,
1982
.
[9]
Nikolas S. Zawodny,et al.
Characterizing the effects of two ground-based outdoor microphone configurations
,
2019,
178th Meeting of the Acoustical Society of America.