Search results for "Acoustic fields"
showing 2 items of 2 documents
3d-Mapping Of Multiple Mirror Sources In A Room: A Two Channel Intensimetric Method.
2005
A large lecture theatre was analyzed by using a 3D intensimetric measurement method. Sweep signal providing the excitation of the environment was sent to an isotropic source. Sound intensity probe was positioned in some test points of the room and sound intensity vector decay was measured for each of them. The sound board of a PC was utilized to acquire couples of impulse responses for each sound intensity vector component. These signals were combined by using an algorithm implemented in Lab VIEW. Mirror sources were localized and visualized in a three-dimensional map for each measurement point. Resuls are presented as orthogonal projections and 3D-diagrams.
Vertical Line Array (VLA) Beam - Forming Algorithm with constant beam width.
2005
The algorithm proposed is a beam-forming algorithm. Many beam-steering and beam-forming algorithms exist and they are all based on the control of delay times between the signals driving the loudspeakers of the line array; this kind of control produces a variable beam-width depending on steering angle and frequency. In our case beam width doesn't depend on frequency and steering angle because a specific beam forming technique was applied by shading the amplitudes of signals for each element of the array according to the frequency applied. Furthermore a weighting function was utilized for spatial windowing. Spatial windowing allows reduction of secondary lobes without varying the directivity …