The time arrival structure of acoustic pulse signals propagating in ocean waveguides is of great significance for underwater acoustic communication and navigation. Using the deep-sea sound propagation data from the ex...The time arrival structure of acoustic pulse signals propagating in ocean waveguides is of great significance for underwater acoustic communication and navigation. Using the deep-sea sound propagation data from the experiments respectively conducted in the East Indian Ocean(EIO) and the South China Sea(SCS) with explosion sources near the sound channel axis(SCA), long-range transmission loss(TL) and time arrival structure of acoustic pulses for different sound speed profiles(SSPs) are compared. In the EIO environment, sound energy transmitting along the SCA is relatively large, and the corresponding signals arrive first, whereas signals propagating away from the SCA arrive late. In the full receiving depth, it shows a branch structure where the waveform near the SCA arrives earlier than other depths, which is totally different with the characteristics of the sound pulse in the SCS. Combined with the parametric mathematical model of deep-sea sound channel, the influence mechanism of SSP on the time arrival structure of long-range pulse propagation is theoretically analyzed, which well explains the phenomenon observed in the two experiments.展开更多
The multiple-path sound propagation in deep water is conducive to source localization of an underwater target.The transmission losses(TLs) and broadband pulse multiple-path propagation characteristics from a deep rece...The multiple-path sound propagation in deep water is conducive to source localization of an underwater target.The transmission losses(TLs) and broadband pulse multiple-path propagation characteristics from a deep receiver is analyzed by using the experimental data from deep water area in the South China Sea(SCS).The results indicate that the width of the direct zone near the bottom of 4300 m water depth is about 30 km.The TLs in the direct zone near the bottom are much less than those in the shadow zone.It is meaningful for underwater sound source detection.Moreover,the time delay between the direct path and the bottomsurface-reflected path for a receiver near the bottom decreases monotonically with the source range.According to the linear relationship between the time delay of multipath and source range,a source localization method is presented to estimate the range of underwater target.The experimental results show that the estimated ranges are consistent with the global position system(GPS) measurements,and the mean square error of the estimation results is less than 0.28 km.展开更多
In order to acquire hydrologic and acoustic information at the same time,the underwater glider is used as a synchro observing platform and an algorithm of source localization estimation based on the glider in deep wat...In order to acquire hydrologic and acoustic information at the same time,the underwater glider is used as a synchro observing platform and an algorithm of source localization estimation based on the glider in deep water is proposed.The hydrologic and acoustic data acquired by the glider in the Eastern Indian Ocean are used to analyze the self-noise of the glider and the characteristics of acoustics signal propagation.The underwater track of the glider is updated by using underwater dead reckoning.According to the time delay of the received signals,the underwater sound source localization estimation is realized.The results indicate that the self-noise of the glider is quite close to the ambient noise at the no-motor time.The sound transmission losses(TLs)of experiment and simulation are in great agreement.The estimation results of underwater sound source localization are consistent with measurement and the estimation error is less than 5%.The glider loaded with self-contained hydrophones can get hydrologic and acoustic information at the same time,which is important for the acoustic propagation analysis and target localization.展开更多
The sound propagation characteristics in a canyon environment are analyzed using the data from the northern South China Sea. The experimental results show that the energy begins to bend to a deeper place with the dept...The sound propagation characteristics in a canyon environment are analyzed using the data from the northern South China Sea. The experimental results show that the energy begins to bend to a deeper place with the depth change of the canyon and the sound transmission losses(TLs) reach the maximum near the center of the canyon due to the combined effect of the negative gradient sound speed profile and the seabed topography. As the sea become shallow gradually, the energy is concentrated due to the seabed reflection, thus the TLs reduce by over 20 d B compared with the TLs results got from the simple slope to the deep water environment. Moreover, when the convergence effects are less than the loss caused by diffusion,seabed reflection, etc. the TLs are minimized and then increase with an increase in distance.In the last segment, the gradual convergence of the energy is highlighted again, and the TLs decrease 10 d B when the water depth suddenly decreases from 850 m to 311 m within 8 km.Finally, the convergence of sound field, which is caused by the topographic change in the canyon environment, is explained by the ray theory and the parabolic equation method.展开更多
基金supported by the National Natural Science Foundation of China (11874061,U22A2012)the Youth Innovation Promotion Association of Chinese Academy of Sciences (2021023)。
文摘The time arrival structure of acoustic pulse signals propagating in ocean waveguides is of great significance for underwater acoustic communication and navigation. Using the deep-sea sound propagation data from the experiments respectively conducted in the East Indian Ocean(EIO) and the South China Sea(SCS) with explosion sources near the sound channel axis(SCA), long-range transmission loss(TL) and time arrival structure of acoustic pulses for different sound speed profiles(SSPs) are compared. In the EIO environment, sound energy transmitting along the SCA is relatively large, and the corresponding signals arrive first, whereas signals propagating away from the SCA arrive late. In the full receiving depth, it shows a branch structure where the waveform near the SCA arrives earlier than other depths, which is totally different with the characteristics of the sound pulse in the SCS. Combined with the parametric mathematical model of deep-sea sound channel, the influence mechanism of SSP on the time arrival structure of long-range pulse propagation is theoretically analyzed, which well explains the phenomenon observed in the two experiments.
基金supported by the National Natural Science Foundation of China(11434012,41561144006)
文摘The multiple-path sound propagation in deep water is conducive to source localization of an underwater target.The transmission losses(TLs) and broadband pulse multiple-path propagation characteristics from a deep receiver is analyzed by using the experimental data from deep water area in the South China Sea(SCS).The results indicate that the width of the direct zone near the bottom of 4300 m water depth is about 30 km.The TLs in the direct zone near the bottom are much less than those in the shadow zone.It is meaningful for underwater sound source detection.Moreover,the time delay between the direct path and the bottomsurface-reflected path for a receiver near the bottom decreases monotonically with the source range.According to the linear relationship between the time delay of multipath and source range,a source localization method is presented to estimate the range of underwater target.The experimental results show that the estimated ranges are consistent with the global position system(GPS) measurements,and the mean square error of the estimation results is less than 0.28 km.
基金supported by the National Natural Science Foundation of China(11874061,11674349)the Youth Innovation Promotion Association of Chinese Academr of Sciences。
文摘In order to acquire hydrologic and acoustic information at the same time,the underwater glider is used as a synchro observing platform and an algorithm of source localization estimation based on the glider in deep water is proposed.The hydrologic and acoustic data acquired by the glider in the Eastern Indian Ocean are used to analyze the self-noise of the glider and the characteristics of acoustics signal propagation.The underwater track of the glider is updated by using underwater dead reckoning.According to the time delay of the received signals,the underwater sound source localization estimation is realized.The results indicate that the self-noise of the glider is quite close to the ambient noise at the no-motor time.The sound transmission losses(TLs)of experiment and simulation are in great agreement.The estimation results of underwater sound source localization are consistent with measurement and the estimation error is less than 5%.The glider loaded with self-contained hydrophones can get hydrologic and acoustic information at the same time,which is important for the acoustic propagation analysis and target localization.
基金supported by the National Natural Science Foundation of China(11434012,41561144006,11874061)。
文摘The sound propagation characteristics in a canyon environment are analyzed using the data from the northern South China Sea. The experimental results show that the energy begins to bend to a deeper place with the depth change of the canyon and the sound transmission losses(TLs) reach the maximum near the center of the canyon due to the combined effect of the negative gradient sound speed profile and the seabed topography. As the sea become shallow gradually, the energy is concentrated due to the seabed reflection, thus the TLs reduce by over 20 d B compared with the TLs results got from the simple slope to the deep water environment. Moreover, when the convergence effects are less than the loss caused by diffusion,seabed reflection, etc. the TLs are minimized and then increase with an increase in distance.In the last segment, the gradual convergence of the energy is highlighted again, and the TLs decrease 10 d B when the water depth suddenly decreases from 850 m to 311 m within 8 km.Finally, the convergence of sound field, which is caused by the topographic change in the canyon environment, is explained by the ray theory and the parabolic equation method.
