海底热液温度场声学测量系统的初步研究

Preliminary study of an acoustic temperature measuring system for seafloor hydrothermal vents

研制一套海底热液声学温度场测量系统.在测量平面周围布置多个水声换能器,分别测得每两个换能器之间的声波飞渡时间.根据海水中声速与海水温度之间的关系,使用最小二乘重建算法对测量平面内的温度场进行重建,论述了水声换能器声中心距离校正,广义互相关时延估计以及总体最小二乘重建算法等关键技术在系统中的应用.进行了水声换能器声中心距离校正和声学测温实验,给出结果并进行了误差分析.声学测温实验结果最大绝对误差3.2k,最大相对误差1.02%,均方根误差0.44%,温度场形态和实际温度分布基本吻合,验证了测量系统及其关键技术的可行性.

An acoustic measuring system is designed to recover the temperature distribution around sea-floor hydrothermal vents.Several acoustic transducers are arranged around the measuring plane and the acoustic wave transit times between each transducer are obtained.The temperature field of the measuring plane can be reconstructed using least squares method based on the relationship between sound speed and water temperature.Several key technologies are discussed in the article,such as center-to-center distance calibration,generalized cross-correlation time-delay esti-mation and reconstruction algorithm based on total least-squares method.The center-to-center distance calibration and the acoustic temperature measuring experiments are performed.The experimental results and the analysis are given.The result of acoustic temperature measuring has a maximum absolute error of 3.280 7 K,a maximum relative error of 1.02 % and an rms error of 0.44%.The shape of the recovered temperature field also agrees with the actual temperature distribu-tion.These facts show that the temperature measuring system and the key technologies are feasible.