星载氦光泵磁矢量测量技术及快速DPSD算法研究

发布时间：2018-04-28 07:34

本文选题：卫星磁测 + 氦光泵磁力仪　；参考：《吉林大学》2017年硕士论文

【摘要】：地磁场具有重要的应用和研究价值,获得地磁场数据从而建立地磁场模型是应用地磁场的基础。与地面磁测、海洋磁测和航空磁测相比,卫星磁测具有测量范围广、测量数据均匀,单次全球测量周期短等许多优点,是获取全球磁场数据更有效的方式。氦光泵磁力仪与磁通门磁力仪是主要的卫星磁测仪器,磁通门磁力仪测量磁场的矢量信息,氦光泵磁力仪主要负责测量磁场的标量信息并定期校准磁通门磁力仪。最新的磁测卫星Swarm上搭载的氦光泵磁力仪不仅实现了磁场的标量测量还实现了对磁场的矢量测量,这是一个突破性的进展,将降低新一代磁测卫星设计的复杂度,进一步提高卫星测量磁场数据的准确性,为多方面的研究工作带来重要的改进。本文以星载氦光泵磁力仪的最新技术进展为参照,重点研究光泵磁力仪实现矢量测量技术的原理、仿真和实验,并对影响光泵磁力仪矢量测量精度的因素进行分析。矢量测量技术对光泵磁力仪的响应速度和采样率有很高的要求,为了进一步提升光泵磁力仪的性能,提高矢量测量结果的精度,通过对影响响应速度和采样率的主要因素进行分析,重点改进了数字相敏检测器(Digital Phase Sensitive Detector,DPSD)的实现算法。现将主要的研究内容归纳如下:(1)以光泵磁力仪实现的基本原理为基础,简要叙述检测系统的实现方法。矢量测量技术以矢量运算为理论基础,通过加入微小交变磁场改变总场信号的频率成分,通过傅里叶变换进行频谱分析,然后计算地磁场的分量。(2)根据光泵磁力仪矢量测量技术的理论分析,首先进行理论仿真计算,计算结果与理论分析一致,证明了理论分析的正确性。然后进行物理仿真,在仿真亥姆霍兹线圈和背景磁场的基础上,研究影响矢量精度的因素,为后期实验的设计提供指导。(3)运用3D打印技术制作双轴亥姆霍兹线圈,通过3D技术的使用,保证了制作线圈几何尺寸的精度,提高了亥姆霍兹线圈产生磁场的精度,并且在屏蔽室进一步对亥姆霍兹线圈的性能参数进行确定。(4)在分析影响光泵磁力仪响应速度的因素上,以数字相敏检测器为突破口,重点分析了乘法器和低通滤波器算法的高效实现。对实现乘法器的CORDIC算法使用流水线结构实现,对实现CIC滤波器和FIR滤波器的算法进行了重新设计。(5)通过实验测量,对矢量技术进行验证。主要包括确定线圈的性能参数,选择稳定的磁场环境进行测试实验。最后经过对结果的计算分析,虽然有0.9%左右误差,但是仍然可以证明整个设计过程是合理有效的。
[Abstract]:Geomagnetic field has important application and research value. It is the foundation of geomagnetic application to obtain geomagnetic data and establish geomagnetic field model. Compared with ground magnetic measurement, marine magnetic measurement and aeromagnetic measurement, satellite magnetic measurement has many advantages, such as wide measurement range, uniform measurement data, short global measurement period and so on. It is a more effective way to obtain global magnetic field data. Helium optical pump magnetometer and fluxgate magnetometer are the main satellite magnetometer. The flux gate magnetometer measures the vector information of the magnetic field. The helium optical pump magnetometer is mainly responsible for measuring the scalar information of the magnetic field and calibrating the flux gate magnetometer regularly. The helium light pump magnetometer on the latest magnetic measurement satellite Swarm not only realizes the scalar measurement of magnetic field but also the vector measurement of magnetic field. This is a breakthrough and will reduce the complexity of the design of the new generation of magnetic measurement satellite. Further improving the accuracy of satellite magnetic field data will bring important improvement to many aspects of research work. In this paper, the principle, simulation and experiment of vector measurement of optical pump magnetometer are studied with reference to the latest technical progress of spaceborne helium optical pump magnetometer, and the factors that affect the accuracy of vector measurement of optical pump magnetometer are analyzed. In order to improve the performance of the optical pump magnetometer and improve the accuracy of the vector measurement, the vector measurement technology has high requirements for the response speed and sampling rate of the optical pump magnetometer. Based on the analysis of the main factors affecting the response speed and sampling rate, the algorithm of digital Phase Sensitive detector DPSD is improved. In this paper, the main research contents are summarized as follows: (1) based on the basic principle of optical pump magnetometer, the realization method of the detection system is briefly described. Based on the theory of vector operation, the vector measurement technology changes the frequency component of the total field signal by adding a small alternating magnetic field, and analyzes the frequency spectrum by Fourier transform. Then the component of geomagnetic field is calculated. (2) according to the theoretical analysis of the vector measurement technology of optical pump magnetometer, the theoretical simulation is carried out, and the calculated results are in agreement with the theoretical analysis, which proves the correctness of the theoretical analysis. Based on the simulation of Helmholtz coil and background magnetic field, the factors affecting vector accuracy are studied to provide guidance for the later experiment design. (3) using 3D printing technology to fabricate the biaxial Helmholtz coil. Through the use of 3D technology, the precision of the geometric dimension of the coil is guaranteed, and the accuracy of the magnetic field generated by the Helmholtz coil is improved. Furthermore, in the shielding room, the performance parameters of Helmholtz coil are determined. 4) in the analysis of the factors that affect the response speed of the optically pumped magnetometer, the digital phase sensitive detector is used as the breakthrough point. The efficient implementation of multiplier and low pass filter algorithm is analyzed. The CORDIC algorithm of multiplier is implemented with pipeline structure. The algorithm of realizing CIC filter and FIR filter is redesigned. It mainly includes determining the performance parameters of the coil and selecting a stable magnetic field environment for testing. Finally, through the calculation and analysis of the results, although there is about 0.9% error, it can still be proved that the whole design process is reasonable and effective.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM936

【相似文献】