基于参数估计的光纤水听器解调系统研究  

Optical fiber hydrophone demodulation system based on parameter estimation method

作　　者：施清平[1,2,3] 王凯[4] 王利威[3] 张华勇[3] 田芊[1,2] 

机构地区：[1]清华大学精密仪器与机械学系 [2]清华大学精密测试技术及仪器国家重点实验室,北京100084 [3]清华大学电子工程系光纤传感研究中心,北京100084 [4]天津大学精密测试技术及仪器国家重点实验室,天津300072

出　　处：《仪器仪表学报》2011年第8期1864-1870,共7页Chinese Journal of Scientific Instrument

摘　　要：研究并实现了可工程应用的光纤水听器解调系统,采用相除查找表的PGC解调方案和逐步参数估计的参数提取方法。从理论上详细阐述了参数提取方法原理,并从实验上分析了该方法的稳定性和有效性。实验测试表明1倍频/2倍频相位延迟的提取精度优于5%。光强、伴生调幅和角度修正因子的估算精度分别达到0.5%,2.5%和5%,能够满足实际工程应用要求。所研制的光纤水听器解调系统解调结果谐波分量较少,失真小。相比于标准压电水听器系统,具有很好的线性度。解调系统噪声本底达到-90 dB/Hz@100 Hz和-95 dB/Hz@1 kHz。10 h连续测试,SINAD方差小于1 dB,THD方差约为2 dB,表明系统具有较好的稳定性。上述技术指标,达到了目前工程应用要求。An optical fiber hydrophone demodulation system based on division lookup table （DLT） phase generated carrier （PGC） and progressive parameter estimation method is implemented and its engineering application is studied. The principle of the parameter extraction method is described in detail theoretically and its stability and eftec- tiveness are analyzed experimentally. Experimental tests show that the extraction accuracy of fundamental/second- harmonic signal phase delay is better than 5%. The estimation accuracies of intensity, accompanying amplitude modulation and phase correction factor are 0.5% , 2.5% and 5% , respectively, which meet the requirements of practical engineering application. The demodulation result of this new optical fiber system has small harmonic distor- tion and its linearity is equivalent to that of standard piezoelectric hydrophone. The background noise of the demodu- lated system reaches - 90 dB/Hz@ 100 Hz and - 95 dB/Hz@ 1 kHz. The variance of Signal to Noise and Distortion ratio （SINAD） is less than 1 dB and the variance of Total Harmonic Distortion ratio （THD） is about 2 dB during 10 hour continuous experiment. These experimental results confirm that this system has good stability, linearity and noise characteristic, which meet engineering application requirements.

关 键 词：光纤水听器 相位生成载波 椭圆参数估计 系统稳定性 工程应用 

分 类 号：TP212.14[自动化与计算机技术—检测技术与自动化装置]