Abstract
This paper presents a measurement method combining conventional and coherent Doppler sonar using an adaptive algorithm to reduce measurement error at a wide range of SNRs. In our previous paper, we proposed a combined method to provide accurate and precise velocity using a fixed range of ambiguity velocity. The combined method worked well at high SNRs, but at low SNRs it was not as accurate. In order to provide accurate velocity at a wide range of SNRs, an adaptive algorithm for the range of ambiguity velocity is proposed at navigators' request. The results of theoretical and numerical error analyses showed that the combined method using the adaptive algorithm provides accurate and precise velocities at a wide range of SNRs.
