For the first time in the world, underwater acoustic transmission of images, human voice, data and texts between vehicle under 7000 m depth and surface ship was accomplished by underwater acoustic communication system...For the first time in the world, underwater acoustic transmission of images, human voice, data and texts between vehicle under 7000 m depth and surface ship was accomplished by underwater acoustic communication system of manned deep submersible Jiaolong＇. In this paper, signal processing in underwater acoustic communication system for manned deep submersible ＂Jiaolong＂ is introduced. （1） Four communication methods are integrated to meet different needs： 1） coherent underwater acoustic communication, with a variable transmission rate from 5 kbps to 15 kbps, to transmit images. 2） Non-coherent underwater acoustic com- munication, with a transmission rate 300 bps, to transmit texts, instructions, and sensor data. 3） Spread spectrum underwater acoustic communication, with a transmission rate 16 bps, to transmit instructions. 4） Underwater voice communication, using single sideband modulation to transmit hmnan voice. （2） Signal processing method in coherent communication mainly consists of concatenation of decision feedback equalizer and Turbo decoder, and wavelet based image compression with fixed length coding. In the equalizer, Doppler compensation, multi- channel combining and equalizer coefficients updating are all using fast self-optimized adaptive algorithm. （3） A linear hydrophone array is lowered from the mother ship to certain depth, and spatial diversity combining technology is adopted. （4） Diving trials of ＂Jiaolong＂ were carried out in Pacific Ocean. The communication range can cover nearly all ocean depth. One optical/acoustic image can be transmitted in 7 or 14 seconds.展开更多
Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a su...Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.展开更多
Near-bottom observation data from the manned deep submersible Jiaolong with high-precision underwater positioning data from Weijia Guyot,Magellan Seamounts in the Western Pacific Ocean are reported.Three substrate typ...Near-bottom observation data from the manned deep submersible Jiaolong with high-precision underwater positioning data from Weijia Guyot,Magellan Seamounts in the Western Pacific Ocean are reported.Three substrate types were identified:Sediment,ferromanganese crust,and ferromanganese crust with a thin cover of sediment.The ferromanganese crusts show clear zoning and their continuity is usually disturbed by sediments on areas of the mountainside with relatively gentle slope gradients.The identified substrate spatial distributions correspond to acoustic backscatter intensity data,with regions of high intensity always including crust development and regions of low intensity always having sediment.Therefore,acoustic backscatter intensity surveying appears useful in the delineation and evaluation of crust resources,although further more work is needed to develop a practicable methodology.展开更多
介绍深海油气勘探开发的现状,从工作水深、海况适应性、可变载荷、结构、材料、装备、功能等多方面分析了第五、第六代深海半潜式钻井平台的发展特点和趋势,并在现场调研的基础上对新一代半潜式钻井平台GlobalSantaFe Development Dril...介绍深海油气勘探开发的现状,从工作水深、海况适应性、可变载荷、结构、材料、装备、功能等多方面分析了第五、第六代深海半潜式钻井平台的发展特点和趋势,并在现场调研的基础上对新一代半潜式钻井平台GlobalSantaFe Development Driller进行了技术说明。展开更多
基金supported by the Chinese National 863 Projects(2002AA401004,2009AA093301,2009AA093601)
文摘For the first time in the world, underwater acoustic transmission of images, human voice, data and texts between vehicle under 7000 m depth and surface ship was accomplished by underwater acoustic communication system of manned deep submersible Jiaolong＇. In this paper, signal processing in underwater acoustic communication system for manned deep submersible ＂Jiaolong＂ is introduced. （1） Four communication methods are integrated to meet different needs： 1） coherent underwater acoustic communication, with a variable transmission rate from 5 kbps to 15 kbps, to transmit images. 2） Non-coherent underwater acoustic com- munication, with a transmission rate 300 bps, to transmit texts, instructions, and sensor data. 3） Spread spectrum underwater acoustic communication, with a transmission rate 16 bps, to transmit instructions. 4） Underwater voice communication, using single sideband modulation to transmit hmnan voice. （2） Signal processing method in coherent communication mainly consists of concatenation of decision feedback equalizer and Turbo decoder, and wavelet based image compression with fixed length coding. In the equalizer, Doppler compensation, multi- channel combining and equalizer coefficients updating are all using fast self-optimized adaptive algorithm. （3） A linear hydrophone array is lowered from the mother ship to certain depth, and spatial diversity combining technology is adopted. （4） Diving trials of ＂Jiaolong＂ were carried out in Pacific Ocean. The communication range can cover nearly all ocean depth. One optical/acoustic image can be transmitted in 7 or 14 seconds.
基金Supported by the "863" Foundation under Grant No.2002AA401000
文摘Variable ballast systems are necessary for manned submersibles to adjust their buoyancy.In this paper,the design of a variable ballast system for a manned submersible is described.The variable ballast system uses a super high pressure hydraulic seawater system.A super high pressure seawater pump and a deep-sea brushless DC motor are used to pump seawater into or from the variable ballast tank,increasing or decreasing the weight of the manned submersible.A magnetostrictive linear displacement transducer can detect the seawater level in the variable ballast tank.Some seawater valves are used to control pumping direction and control on-off states.The design and testing procedure for the valves is described.Finally,the future development of variable ballast systems and seawater hydraulic systems is projected.
基金This studywas funded by the Resource and Environment COMRA Projects (DY135-C1-1-02,DY135-C1-1-01)the China Geological Survey(DD20191009).
文摘Near-bottom observation data from the manned deep submersible Jiaolong with high-precision underwater positioning data from Weijia Guyot,Magellan Seamounts in the Western Pacific Ocean are reported.Three substrate types were identified:Sediment,ferromanganese crust,and ferromanganese crust with a thin cover of sediment.The ferromanganese crusts show clear zoning and their continuity is usually disturbed by sediments on areas of the mountainside with relatively gentle slope gradients.The identified substrate spatial distributions correspond to acoustic backscatter intensity data,with regions of high intensity always including crust development and regions of low intensity always having sediment.Therefore,acoustic backscatter intensity surveying appears useful in the delineation and evaluation of crust resources,although further more work is needed to develop a practicable methodology.
