Scintillation instrument for remote environmental analysis (SIREN)

Abstract

A high frequency acoustic propagation instrument which was developed to study ocean variability in the Strait of Istanbul (Bosporus) is described. The scintillation instrument for remote environmental analysis (SIREN) was designed in modular form taking advantage of modern digital signal processing

hardware and software so that data can be acquired continuously at relatively high transmission rates and in reciprocal directions. The overall design and operation of the system proved to be very good except for a digitization triggering problem, caused by a distorted trigger signal as a result of the long underwater cables used. This problem affected the measurement of the acoustic phase and hence the accuracy of ocean parameters for turbulence measurements. The amplitude however can be used as a measure of the total scattered signal due to turbulent sound speed and current velocity. The mean travel time gives mean ocean variability. The experimental period is summarized and the data processing techniques are described.