Comparing measurement correction of echo sounder in shallow-water area

Error correction of echo sounder is very important for the accurate measurement of water-depth in shallow-water area. There are some issues in measuring the water depth, they are accuracy, resolution, inaccurate beamwidth of transmit and can be solved by the existing methodologies. In this article, comparing measurement is an efficient method for error correction of echo sounder. The most commonly used comparing methods are sounding poles, plumb-lines and thermohaline methods. However, the sounding poles method can only measure the water-depth less than 5 m as its limited by the length of measuring poles; the plumb-lines method cannot guarantee the accuracy of water-depth value as its difficult to determine whether the plumb-line falls vertically onto the water floor or into the underwater sediment; the thermohaline methods is time-consuming as its need lots of the temperature and salinity information for the correction of sound velocity. Based on these knowledge and experience, we put forward a comparator for comparing measurement of water-depth, which could adjust sound velocity of echo sounder for precisely measure actual water-depth of the survey area without complicated thermohaline correction work. The comparator method has practical implications for the quick error correction of echo sounder survey in shallow-water area. The experimental results predict that the mistakes are easily caused by the complicated correction work which can be avoided and establishes that the water-depth measurement is more efficient.