A Measurement Platform for the Evaluation of Sparse Acoustic Array Geometries.

Sparse arrays have the ability to estimate the Direction-of-Arrival (DoA) of more sources than available sensors by placing sensors in a specific geometry. This reduces the hardware complexity, respectively provides the possibility of estimating a large number of concurrent sources. In this contribution we present a measurement platform to experimentally test several sparse array geometries. The developed acoustic microphone array consists of an 8x8 grid, i.e. 64 microphones in Uniform Rectangular Array (URA) configuration, with a grid spacing of 8.255 mm, resulting in a spatial Nyquist frequency of around 20.8 kHz in the acoustic domain at room temperature. This enables to mask sensors, in order to represent sparse array configurations. We present the working principles of the developed hardware platform, as well as 2-D Angle-of-Arrival (AoA) measurements with one and two concurrent sources to compare algorithms and geometries with experimental data.