绝对重力仪时间测量技术研究

发布时间：2018-02-27 18:02

本文关键词： TDC502 绝对重力仪时间测量 FPGA　出处：《中国地震局地震研究所》2013年硕士论文　论文类型：学位论文

【摘要】：地球重力场反映了地球密度分布、地球自转运动等物理信息，，是地球科学的基础信息资源。绝对重力仪是高精度地获取地球重力场信息的重要仪器之一。目前绝对重力测量系统主要通过自由落体获得相位差，利用激光干涉原理获得下落时间和位移量的观测量，从而计算出重力加速度g。随着激光、真空技术、电子技术等新兴技术的日益成熟、精密机械工艺的提高，相关测量方法和误差原理的优化，使绝对重力仪的精度不断提高，新一代绝对重力仪FG5精度达到1×10~(-8)ms~(-2)。在绝对重力测量系统中，影响精度的因素主要包括激光频率稳定性、落体舱真空度、重力梯度测量、干涉条纹时间周期的测量精度。而高精度的时间测量技术在科研、国防以及工业领域有着广泛的应用，随着信息化社会的高速发展，有越来越多的领域需要应用到高精度时间测量技术，国外在高精度时间测量方面已经走在前列，我国的高精度时间测量技术还在发展阶段，因此对于这方面的研究是有必要的。本文阐述绝对重力仪对自由落体下落距离和相对应的时间测量的原理和方法。利用高精度时间测量芯片TDC502提高绝对重力仪的时间测量精度，并结合FPGA的大规模数字集成设计，从而提高重力仪系统的测量精度。
[Abstract]:The gravity field of the earth reflects the physical information such as the density distribution of the earth, the movement of the earth's rotation, etc. The absolute gravimeter is one of the important instruments to obtain the information of the earth's gravity field with high accuracy. At present, the absolute gravity measurement system obtains the phase difference mainly through the free falling body. The observation of falling time and displacement is obtained by using the principle of laser interference, and the gravity acceleration g is calculated. With the development of new technologies such as laser, vacuum technology and electronic technology, the precision mechanical technology is improved. The accuracy of the absolute gravimeter is improved by the optimization of the correlation measurement method and the error principle. The FG5 accuracy of the new generation absolute gravimeter is 1 脳 10 ~ (-8) Ms ~ (-1). In the absolute gravity measurement system, the main factors affecting the accuracy include laser frequency stability, falling chamber vacuum, gravity gradient measurement, interference fringes time period measurement accuracy, and high precision time measurement technology in scientific research. With the rapid development of information society, more and more fields need to be applied to high-precision time measurement technology. Foreign countries have been in the forefront of high-precision time measurement. The high-precision time measurement technology in China is still in the developing stage, so it is necessary to study this aspect. In this paper, the principle and method of absolute gravimeter for measuring the falling distance of free falling body and the corresponding time are described. The time measurement accuracy of absolute gravimeter is improved by using high precision time measurement chip TDC502, and the large scale digital integration design of FPGA is combined with this method. In order to improve the measuring accuracy of gravimeter system.
【学位授予单位】：中国地震局地震研究所
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：P223.1

【参考文献】