Evaluation of ADCP backscatter computation for quantifying suspended sediment concentration

Abstract

Suspended sediment concentration (SSC) is important to measure for knowing photosynthesis activity and as indicator of marine pollution. Now days, measurement method to study about SSC were used conventional and optical techniques. These methods had a limitation in providing temporal data of SSC. Acoustic Doppler Current Profilers (ADCP) originally designed for measuring ocean current and its velocity profiles. In fact, ADCP is not only limited to measure the ocean current velocity and direction, but include measuring acoustic backscattering intensity which is related to the concentration of suspended sediment. Based on sonar equations, we computed and analysed the relationship between the backscattering intensity and suspended sediment concentration. In study area of Jakarta Bay, the highest SSC was 70 mgL-1 and the lowest SSC was 30 mgL-1. Compared to the traditional method, ADCP method has many advantages in providing spatial and temporal data.