Acoustic remote sensing is a widely used technique for exploring the ocean internal structure. The multi-channel seismic method, or the so-called seismic oceanography, is such an acoustic remote sensing technique that uses the low-frequency active source acoustic signals (~50Hz) to detect various physical oceanographic processes with the advantages of high lateral resolution (~10 m), high efficiency (~200 km/day), and full-depth coverage of the water column. The derived continuous acoustic image can reveal fines structures of the oceanic processes from small scale to mesoscale, and even to basin scale.

Here we review four study cases of internal wave observation using seismic oceanography: (1) first time detection of the internal solitons, (2) second time verifying the ability in capturing internal packets, (3) temperature/salinity inversion of internal wave field from seismic data, and (4) an anomalous high-mode internal wave observation. And the potential capability and application of seismic oceanographic observations for the study of internal isolated waves are proposed. Such a novel technique is suitable to the increasing demand for high resolution in the hydrographic observation, and will provide new approaches on ocean internal wave studies.