摘要
The estimation of ocean sound speed profiles(SSPs)requires the inversion of an acoustic field using limited observations.Such inverse problems are underdetermined,and require regularization to ensure physically realistic solutions.The empirical orthonormal function(EOF)is capable of a very large compression of the data set.In this paper,the non-linear response of the sound pressure to SSP is linearized using a first order Taylor expansion,and the pressure is expanded in a sparse domain using EOFs.Since the parameters of the inverse model are sparse,compressive sensing(CS)can help solve such underdetermined problems accurately,efficiently,and with enhanced resolution.Here,the orthogonal matching pursuit(OMP)is used to estimate range-independent acoustic SSPs using the simulated acoustic field.The superior resolution of OMP is demonstrated with the SSP data from the South China Sea experiment.By shortening the duration of the training set,the temporal correlation between EOF and test sets is enhanced,and the accuracy of sound velocity inversion is improved.The SSP estimation error versus depth is calculated,and the 99%confidence interval of error is within±0.6 m/s.The 82%of mean absolute error(MAE)is less than 1 m/s.It is shown that SSPs can be well estimated using OMP.
The estimation of ocean sound speed profiles(SSPs) requires the inversion of an acoustic field using limited observations. Such inverse problems are underdetermined, and require regularization to ensure physically realistic solutions. The empirical orthonormal function(EOF) is capable of a very large compression of the data set. In this paper, the non-linear response of the sound pressure to SSP is linearized using a first order Taylor expansion, and the pressure is expanded in a sparse domain using EOFs. Since the parameters of the inverse model are sparse, compressive sensing(CS) can help solve such underdetermined problems accurately,efficiently, and with enhanced resolution. Here, the orthogonal matching pursuit(OMP) is used to estimate range-independent acoustic SSPs using the simulated acoustic field. The superior resolution of OMP is demonstrated with the SSP data from the South China Sea experiment. By shortening the duration of the training set, the temporal correlation between EOF and test sets is enhanced, and the accuracy of sound velocity inversion is improved. The SSP estimation error versus depth is calculated, and the 99% confidence interval of error is within ±0.6 m/s. The 82% of mean absolute error(MAE) is less than 1 m/s. It is shown that SSPs can be well estimated using OMP.
基金
The National Natural Science Foundation of China under contract No.11704225
the Shandong Provincial Natural Science Foundation under contract No.ZR2016AQ23
the State Key Laboratory of Acoustics,Chinese Academy of Sciences under contract No.SKLA201902
the National Key Research and Development Program of China contract No.2018YFC1405900
the SDUST Research Fund under contract No.2019TDJH103
the Talent Introduction Plan for Youth Innovation Team in Universities of Shandong Province(Innovation Team of Satellite Positioning and Navigation)
