XCTD, as one of the most important instruments for the deep sea exploration, is an important device for deep-sea hydrological data acquisition. But some difficult technical problems of traditional metal enameled wire ...XCTD, as one of the most important instruments for the deep sea exploration, is an important device for deep-sea hydrological data acquisition. But some difficult technical problems of traditional metal enameled wire channel have become the major bottleneck for XCTD development. Aiming at this problem, this paper puts forward with using single-mode fiber as the transmission channel of XCTD. Firstly, this paper makes a brief analysis on the problems of using enameled wire as transmission channel faces. Secondly, it analyzes the advantages of the single mode fiber technology. Finally, it makes theoretical research and experimental verification of the influence of seawater temperature change on the optical fiber transmission channel. The experimentat results show that the error rate at the transmission rate of 10 MB/S is 0, and the loss can be negligible when the single-mode fiber channel is used in the sea water and the seawater temperature changes from 0 to 20℃. This method will greatly increase the rate of signal transmission and the transmission stability. And this paper shows that using the single-mode fiber as the transmission channel of XCTD has certain feasibility.展开更多
An expendable conductivity-temperature-depth profiler(XCTD)is one of the most important instruments used to obtain hydrological data,such as temperature and conductivity,and detect ocean depth in a large area.However,...An expendable conductivity-temperature-depth profiler(XCTD)is one of the most important instruments used to obtain hydrological data,such as temperature and conductivity,and detect ocean depth in a large area.However,the XCTD channel provides poor time-varying performance,narrowband,and low signal-to-noise ratio(SNR),which severely restricts the data transmission rate.In contrast to conventional single-carrier modulation techniques,such as amplitude-shift keying and differential phase-shift keying,this article provides a new method,based on orthogonal frequency division multiplexing(OFDM)to enhance the data transmission rate of deep-sea abandoned profilers.We apply the OFDM to enhance the SNR of the XCTD,which is achieved by reducing the data transmission rate of each sub-channel.Moreover,the bandwidth utilization may be improved by increasing the number of subcarriers in a given bandwidth,which enhances the data transmission rate.Based on analysis of the XCTD channel model,OFDM with different parameters such as constellation mapping,number of subcarriers,subcarrier spacing,signal period and cyclic prefix are achieved.To verify the effectiveness of the OFDM,this study investigates the influence of different parameters on the data transmission rate at different noise levels,i.e.,-20 dB and-40 d B.展开更多
海水声速剖面的准确获取对于利用多波束声呐系统进行水深测量至关重要,而传统的声速剖面获取方式都需要停船进行测量,导致海上调查作业效率较低。为了解决该问题,本文首先介绍了温盐深剖面测量仪(CTD)和抛弃式温盐深剖面测量仪(XCTD)间...海水声速剖面的准确获取对于利用多波束声呐系统进行水深测量至关重要,而传统的声速剖面获取方式都需要停船进行测量,导致海上调查作业效率较低。为了解决该问题,本文首先介绍了温盐深剖面测量仪(CTD)和抛弃式温盐深剖面测量仪(XCTD)间接测量声速剖面的原理,然后对"海洋地质六号"调查船在同一站位及时间利用CTD、XCTD和AML PLUS SV声速剖面仪测量得到的声速剖面进行了一个对比分析。研究结果表明,三者测量得到的声速剖面在相同水深处声速互差引起的水深差值最大为0.130 9 m。在多波束水深测量过程中,可考虑使用CTD和XCTD间接测量获得的声速剖面代替声速剖面仪直接测得的声速剖面,通过合理布设CTD站位以及使用XCTD来提高海上多波束水深调查的作业效率。展开更多
投弃式温盐深测量仪(expendable conductivity temperature and depth,XCTD)是一种先进的海洋动力环境要素测量仪器,能够在各种民用、军用船只、飞机或者潜航器上使用,用以快速获取水下环境信息数据。其使用灵活、快捷经济、操作简便,...投弃式温盐深测量仪(expendable conductivity temperature and depth,XCTD)是一种先进的海洋动力环境要素测量仪器,能够在各种民用、军用船只、飞机或者潜航器上使用,用以快速获取水下环境信息数据。其使用灵活、快捷经济、操作简便,是海洋调查的常备仪器,也是对海洋环境监测浮标、潜标、船载CTD等传统测量仪器的重要补充。目前,投弃式温盐深测量仪因其测量投放简便、测量效率高、硬件成本低等特点,在海洋剖面观测领域中被大量使用。为了了解国内外发展的差距,明确该领域未来发展方向,从投弃式海洋仪器设备的分类谈起,通过对比分析和归纳总结,阐述了投弃式温盐深测量仪的国内外发展现状,对比了国内外投弃式温盐深测量仪的主要差距,重点介绍了潜射式温盐深仪(SSXCTD)的工作原理及关键技术,总结了在潜射式温盐深仪的研究领域需要加强研究的方向。展开更多
基金supported by the Research Program of Application Foundation and Advanced Technology of Tianjin (No. 14JCYBJC16300)the National Natural Science Foundation of China (No. 41206031)
文摘XCTD, as one of the most important instruments for the deep sea exploration, is an important device for deep-sea hydrological data acquisition. But some difficult technical problems of traditional metal enameled wire channel have become the major bottleneck for XCTD development. Aiming at this problem, this paper puts forward with using single-mode fiber as the transmission channel of XCTD. Firstly, this paper makes a brief analysis on the problems of using enameled wire as transmission channel faces. Secondly, it analyzes the advantages of the single mode fiber technology. Finally, it makes theoretical research and experimental verification of the influence of seawater temperature change on the optical fiber transmission channel. The experimentat results show that the error rate at the transmission rate of 10 MB/S is 0, and the loss can be negligible when the single-mode fiber channel is used in the sea water and the seawater temperature changes from 0 to 20℃. This method will greatly increase the rate of signal transmission and the transmission stability. And this paper shows that using the single-mode fiber as the transmission channel of XCTD has certain feasibility.
基金supported by the National Key Research and Development Program of China (No. 2016 YFC1400400)the Marine Economic Innovation and Development Demonstration Project in Binhai New Area (No. 1723434C4114194)
文摘An expendable conductivity-temperature-depth profiler(XCTD)is one of the most important instruments used to obtain hydrological data,such as temperature and conductivity,and detect ocean depth in a large area.However,the XCTD channel provides poor time-varying performance,narrowband,and low signal-to-noise ratio(SNR),which severely restricts the data transmission rate.In contrast to conventional single-carrier modulation techniques,such as amplitude-shift keying and differential phase-shift keying,this article provides a new method,based on orthogonal frequency division multiplexing(OFDM)to enhance the data transmission rate of deep-sea abandoned profilers.We apply the OFDM to enhance the SNR of the XCTD,which is achieved by reducing the data transmission rate of each sub-channel.Moreover,the bandwidth utilization may be improved by increasing the number of subcarriers in a given bandwidth,which enhances the data transmission rate.Based on analysis of the XCTD channel model,OFDM with different parameters such as constellation mapping,number of subcarriers,subcarrier spacing,signal period and cyclic prefix are achieved.To verify the effectiveness of the OFDM,this study investigates the influence of different parameters on the data transmission rate at different noise levels,i.e.,-20 dB and-40 d B.
文摘海水声速剖面的准确获取对于利用多波束声呐系统进行水深测量至关重要,而传统的声速剖面获取方式都需要停船进行测量,导致海上调查作业效率较低。为了解决该问题,本文首先介绍了温盐深剖面测量仪(CTD)和抛弃式温盐深剖面测量仪(XCTD)间接测量声速剖面的原理,然后对"海洋地质六号"调查船在同一站位及时间利用CTD、XCTD和AML PLUS SV声速剖面仪测量得到的声速剖面进行了一个对比分析。研究结果表明,三者测量得到的声速剖面在相同水深处声速互差引起的水深差值最大为0.130 9 m。在多波束水深测量过程中,可考虑使用CTD和XCTD间接测量获得的声速剖面代替声速剖面仪直接测得的声速剖面,通过合理布设CTD站位以及使用XCTD来提高海上多波束水深调查的作业效率。
文摘投弃式温盐深测量仪(expendable conductivity temperature and depth,XCTD)是一种先进的海洋动力环境要素测量仪器,能够在各种民用、军用船只、飞机或者潜航器上使用,用以快速获取水下环境信息数据。其使用灵活、快捷经济、操作简便,是海洋调查的常备仪器,也是对海洋环境监测浮标、潜标、船载CTD等传统测量仪器的重要补充。目前,投弃式温盐深测量仪因其测量投放简便、测量效率高、硬件成本低等特点,在海洋剖面观测领域中被大量使用。为了了解国内外发展的差距,明确该领域未来发展方向,从投弃式海洋仪器设备的分类谈起,通过对比分析和归纳总结,阐述了投弃式温盐深测量仪的国内外发展现状,对比了国内外投弃式温盐深测量仪的主要差距,重点介绍了潜射式温盐深仪(SSXCTD)的工作原理及关键技术,总结了在潜射式温盐深仪的研究领域需要加强研究的方向。
