An self-adaptive correction method with eliminating the influence of angular response for multi-beam acoustic intensity data

The multibeam Backscatter Strength(BS)is greatly affected by acoustic scattering mechanism when sampling the multibeam acoustic data,which is the so-called Angular Response(AR).While,the acoustic hardware has not weakened the AR effect perfectly,and it is unsatisfactory for published post processing methods to correct the BS on the complex seabed sediment,especially in the high-iricident-angle domain.An improved self-adaptive angular response correction model for the multibeam backscatter strength data is proposed.Firstly,the average of the BS for continuous Pings data was computed to obtain the AR curve;Secondly,the AR model correction parameters are extracted by means of the second derivative approach on the fitting AR curve generated from the previous one using gauss fitting method.Finally,the BS sectional processing correction model for a single Ping was present,which takes the high-incidence-angle domain into account.The experimental results indicated tliat the mean deviation among entire transmitting section was decreased by about 30%compared with the traditional model.Especially,in the high-incidence-angle-domain,the mean deviation reduced by nearly 40 V compare with traditional model,the standard deviation reduced by approximately 30%as well.The proposed method not only can solve the problem of obtaining the precise backscatter strength data on the seabed,which can weaken the influence of scattering mechanism,but also it can avoid these troubles such as BS inhomogeneity,abnormal correction in the central domain which suffered from the AR effect.Therefore,the reliability of multibeam backscatter strength is improved,what is more,it can present the actual geomorphology of the seabed.