Application of complex MEM processing for measuring reflective architecture in acoustical archaeology

Abstract

A measurement of reflective characteristics of architecture is one of the fundamental studies in acoustical archaeology. In this paper an application of maximum entropy method (MEM) processing is discussed for measuring the characteristics of reflective architecture in acoustic archaeology by computer simulation. Chirp signals are supposed to be transmitted from a speaker and reflected acoustical signals of amplitude and phase are recorded using several receivers. Since the received signals are complex, MEM algorithms for processing complex signals are developed and the relative distances between reflective targets and receivers are calculated, resulting in the identification of the location of the targets in 2-D space. In a different view, the proposed mesurement technique is a reconstruction of a target from a one-dimensional complex acoustical hologram. Computer simulation is done in which chirp signals are supposed to be reflected from a target and complex acoustical signals are generated by superposing the signals received by several receivers. Pulse compression of signals of different receivers is conducted using the proposed MEM algorithm, resulting in detection of the distances between the target and receivers. Application of the proposed method to the measurement of the reflective characteristics of architecture in acoustic archaeology is discussed.