Passive Velocity Estimation of a Distant Harmonic Source in a Pekeris Waveguide Based on Modal Doppler Shifts

Abstract

The acoustic field generated by a moving point source in terms of normal modes predicts that each mode has a different Doppler shift, i.e., modal Doppler shifts, which contains the velocity information of the moving source. This paper presents a method to estimate the velocity of a distant harmonic source in a Pekeris waveguide passively based on modal Doppler shifts. Combined with the fact that the modal depth function varies slowly with frequency, a cost function is designed to realize the velocity estimation of a distant harmonic source with a single hydrophone when the bottom parameters are unknown. The effectiveness of the method is validated by simulations.

Moving harmonic source depth estimation by MDFMD-v in a weakly range-depend waveguide

“…where ( ) mr kr  at this location can be estimated by the MP method [9]. When ( , ) mr kr  are estimated, the corresponding mode depth functions…”

“…In this case, to estimate the source depth, it is necessary to know the mode depth functions of source and HLA locations to decouple the amplitude of each mode excited by the source. Under the assumption that sound speed profile (SSP) is known, the mode depth functions at the HLA and the source locations can be extracted based on matrix pencil (MP) [8] and modal depth function constrained modal Doppler velocity estimation (MDFMD-v) [9] respectively by combing the difference equation introduced in Ref. [10].…”