Method of Measuring Depth Profile of Suspended Matter Using ADCP and Statistical Analysis

The Acoustic Doppler Current Profiler (ADCP) is an effective tool for use in measuring the current field within the water column. It can also be used to measure the echo intensity in each measurement layer, and results can then be correlated with the configuration and concentration of suspended matter. This paper suggests a method for measuring the underwater concentration of suspended matter using the ADCP. To determine the relationship between concentration and echo intensity, laboratory experiments were conducted in water tanks using ADCP and turbidity sensors. A model was then constructed in this respect. The ADCP was then used to measure the echo intensity under the sea, to verify the turbidity and fluorescence strength of the water. Finally, principal component analysis (PCA) and principal regression analysis (PCR) were applied against the echo intensity. We were able to estimate concentration of turbidity and plankton from echo intensity of ADCP.