Abstract
An acoustic method in air has the potential to allow for the fast and accurate characterization of objects in air. Nevertheless, it is difficult to identify acoustic signals clearly because of environmental noises and the scattering of signals on the object surface. Therefore, it is required to establish a sensing system, which enables measurements in air. In this paper, we present the object detection using an M-sequence signal in an indoor environment. Using the M-sequence signal enabled the improvement in signal-to-noise (SN) ratio and the stable measurement of reflected waves that cannot be detected using a conventional impulse. The noise and reverberation components are included in the received signals and reflected waves from the target. We confirmed that in the case of a high-order M-sequence signal, target detectability is limited by reverberation. In addition, we eliminated the reverberation component from the received signals using the signals without the target in the reverberation limited case and determined the reflection characteristics of the target.