自容式海洋压力测量系统设计

在海洋科学研究中,压力测量技术已经得到广泛应用。针对海洋科学研究领域对低功耗、高精度及宽温度范围的需求,系统描述了一个使用硅压力传感器的设计方案,并给出了一种硅压力传感器的温度补偿方法及其标定算法,实现了宽温度范围下硅压力传感器的高精度测量。     

C＋＋Builder环境下测温系统后台软件的实现

温度作为一项重要的物理参数,广泛应用于海洋气象、水文、渔业、电力及各种工业控制领域。该后台软件旨在Wingdows XP操作系统下,以C Builder这种高效开发环境为平台,通过ADO方式连接后端Microsoft Access 2003数据库,实现集RS 232串口测温系统中的实时数据采集、实时曲线绘制与数据库管理于一体的后台软件的快速、高效开发。实际运行表明,该后台软件以实时曲线绘制的方式形象、直观的显示了采集的温度数据,运行良好。     

帧同步系统的FPGA设计与实现

为能在数字通信系统的接收端将每帧数据区分开,实现正确译码,提出一种采用FPGA实现帧同步系统的设计方案。同步保护电路的设计提高系统的可靠性,在Quartus II开发软件上用硬件描述语言实现帧同步电路设计,并给出FPGA设计的实验仿真,实验结果表明该电路系统工作正确可靠,满足设计要求。     

Performance improvement of a self-heterodyne detection BOTDR system employing broad-band laser

The self-heterodyne detection Brillouin optical time domain reflectometer (BOTDR) system using broad-band laser is proposed to reduce coherent Rayleigh noise and improve the system performance. Compared with the system with narrow-band laser, the stimulated Brillouin scattering (SBS) threshold can be improved by about 3 dB. The experimental results of the narrow-band laser measurements for three times independently and the broad-band laser measurement for one time are compared. The root-mean-square (RMS) errors of Brillouin linewidth for two systems with narrow-band laser and broad-band laser are 6.9 MHz and 2.7 MHz, respectively, and the RMS errors of temperature for the heated fiber are about 1.3 °C and 0.7 °C. With the broad-band laser, signal-to-noise ratio (SNR) of the unheated fiber is approximately equivalent to that of the integrated three independent Brillouin signals for the narrowband laser, and the results are believed to be beneficial for performance improvement and measurement time reduction.     

BCH纠错码在FPGA上的实现

主要介绍了BCH码的结构和一般译码方法,重点讨论了BCH(31,21)的编译码方法,提出了一种适合在FPGA上实现的BCH译码算法。并用ALTERA公司FLEX10K20器件实现了BCH(31,21)纠错编解码。经实验测试,对于码组中任两住随机错误都可以给予纠正,且运行可靠。目前,该BCH编译码器已成功地应用在某数学传输系统中。     

帧同步系统的FPGA设计与实现

为能在数字通信系统的接收端将每帧数据区分开.实现正确译码,提出一种采用FPGA实现帧同步系统的设计方案.同步保护电路的设计提高系统的可靠性,在Quartus II开发软件上用硬件描述语言实现帧同步电路设计,并给出FPGA设计的实验仿真,实验结果表明该电路系统工作正确可靠,满足设计要求.     

串行接口器件及其应用

介绍I^2C总线接口和同步串行接口的串行通讯方式，并给出用单片机I／O口模拟这2种接口的子程序.     

高精度光纤光栅波长解调方法研究综述

光纤布拉格光栅传感器采用波长变化反映被测量大小,因此提高光纤光栅的波长解调精度具有重要意义.传统解调方法大多结构单一导致性能受限且对于重叠谱和畸变谱的测量精度欠佳,限制了解调精度的提升.高精度波长解调方法主要解决系统温度稳定性差和寻峰精度低等问题.文章介绍了光通信中光纤光栅波长解调技术的应用,综述了近几年高精度光纤光栅...     

A performance enhanced Rayleigh Brillouin optical time domain analysis sensing system

Aiming at the problem of large fading noise in Rayleigh Brillouin optical time domain analysis system, a wavelength scanning technique is proposed to enhance the performance of the temperature sensing system. The principle of the proposed technique to reduce the fading noise is introduced based on the analysis of Rayleigh Brillouin optical time domain analysis system. The experimental results show that the signal-to-noise ratio (SNR) at the end of optical fiber with length of 50 m after 17 times wavelength scanning is 5.21 dB higher than that with single wavelength, the Brillouin frequency shift (BFS) on the heated fiber with length of 70 m inserted at the center of sensing fiber can be accurately measured as 0.19 MHz, which is equivalent to a measurement accuracy of 0.19 °C. It indicates that the proposed technique can realize high-accuracy temperature measurement and has huge potential in the field of long-distance and high-accuracy sensing.     

七电极电导率传感器测量电路设计与实现

针对七电极电导率传感器的基本原理和特点进行了阐述,根据传感器本身物理特性以及高精度测量的要求,设计了能够满足低温漂、高精度、速度快的测量电路。采用D/A、A/D等集成电路芯片去实现对传感器的精确驱动和高速采样,相比于传统方式,驱动的频率和电压更加准确,并且容易更改,采用高速采样可以避免信号在调理过程中出现的失真。通过实验验证了电路的测量效果。