ACAM_64
5
between sources that are within the field of view, and sources that are outside, leading to artifacts such
as phantom images.
For
ACAM_64
, the distance between microphones is 23 mm, so that frequencies up to 7.5 kHz can be
imaged properly. In practice the array is sampled at 16 kHz, with a Nyquist frequency of 8 kHz. The anti-
aliasing filters in the camera ensure that the signal energy is low above 7.5 kHz.
3.3
Field of View (
FOV
)
The field of view of a camera represents the number of degrees that the camera can see (that are
represented in the image) in the horizontal plane (azimuth) and vertical plane (elevation).
For
ACAM_64
, the field of view is the same in azimuth and elevation (the image is square). There are
two possible settings:
•
90 degrees
(-45 degrees to +45 degrees from left to right and from bottom to top)
•
60 degrees
(-30 degrees to +30 degrees from left to right and from bottom to top)
3.4
Audio Beamformer
The acoustic “sum” signal corresponding to any pixel position is available and can be streamed out
of the processing engine, to be listened to. This process is called “beamforming”. The microphone
array can be digitally steered to the angle of incidence corresponding to any pixel in the field of view
and focus on that source. In addition, since the image shows the azimuth and elevation of the loudest
source in the field of view of the camera, the beamformer can be made to follow that “hot-spot” as it
moves across the field of view.
4
Features
•
32x32 real-time image of the acoustic environment, displayed as a thermal map.
•
Ready to run application provided for Windows.
•
The beamformer can capture the audio signal at any specific direction within the field of view of
the camera
•
Using the provided application, the audio capture can track the source direction, following the
source as it moves within the field of view of the camera.
•
Frequency response can be adjusted by defining lower and upper frequency limits.
•
Adjustable field of view: 60 deg or 90 deg.
•
Adjustable image persistence from 10ms to 10s
•
Massively parallel real-time all-digital design. Can build every pixel of the image from every
sample captured by every microphone in the array.
•
Open communication protocol allows applications designed by OEMs
•
Editable individual custom ID for easier instrument management.
