【作者】 张杨；

【导师】 康崇；

【作者基本信息】 哈尔滨工程大学 ， 机械电子工程， 2012， 博士

【摘要】 基于人类对大自然不断的探索、发现以及实际应用的需要，地球磁场以及地磁导航的研究正逐渐成为导航领域的研究热点。通过近几十年的快速发展，已经证明地磁导航具有无源、无辐射、全天时、全天候、全地域、能耗低等优良特征，并且地磁场为矢量场，在地球近地空间内任意一点的地磁矢量都不同于其它地点的矢量，且与该点的地理经纬度存在一一对应的关系。因此，地磁场为航空、航天、航海以及潜航提供了天然的坐标系。本文以国际科技合作项目为背景，研究了地磁导航中的一些关键技术，包括铯光泵磁力仪机理、地磁导航中载体自身消磁技术、磁补偿方法以及载体与磁力仪匹配技术。研究工作主要是下面3个方面：1、为了获得磁力仪与水下载体的最佳匹配点，本文在局部区域进行了地磁测量，并通过克里金插值法重构地磁图。在地磁图中的平缓区域进行水下载体对周围磁场影响实验。结果表明，在所选择的空间中，在未放置和放置水下载体时，磁场变化极为明显，同一位置的测量点相差可达2700nT以上。可见在水下地磁测量时必须考虑水下载体自身磁场的影响，为此我们在载体空间的8个平面进行了8方位载体磁测实验，并通过相关系数法进行了数据分析，得到了2个铯磁力仪与水下载体的最佳匹配点，使铯磁力仪间的差值受载体磁场影响较小。2、常用的消磁方法是以消磁线圈进行消磁，属于“硬补偿”，该方法工序繁琐，设备复杂，受限制较多。本文则主要研究“软补偿”，即在相关匹配的基础上，将水下载体进行水下360°旋转磁测实验，分析了在不同航向上水下载体对铯磁力仪的影响，从而得到水下载体自身磁场的消磁方法，给出不同航向上每个磁力仪测量值的补偿方法，更加真实的还原水下地磁场值，为高精度水下地磁导航及建立水下地磁图打下基础。3、分析了铯原子在磁场中发生塞曼效应而形成塞曼子能级的过程，给出了铯光泵磁力仪的理论分析和系统设计，通过光学布洛赫方程详细解释了在激光抽运时，铯原子各塞曼子能级粒子数随时间演化的过程。可以发现原子在磁场中作拉莫尔进动，而其态矢量在各个塞曼子能级上的分布也同时作一定的周期性变化，当态矢量偏离初始时刻时，由于布居数的改变将对光抽运造成影响，并对入射光的吸收发生显著变化。分析计算了铯原子中各塞曼子能级粒子数变化的速率方程，由此获得了基态和激发态各能级粒子数随时间演化的函数，从而在理论上解释了铯光泵磁力仪的工作机理。更多还原

【Abstract】 Based on the constant exploration, discovery and practical application of nature, theresearch of geomagnetic field and navigation using geomagnetic field have becoming researchhotspot. Along with the rapid development in recent decades, it has be proved that thegeomagnetic field navigation has the outstanding feature of passive, no radiation, all time, allweather, all terrain and low power. The geomagnetic field belongs to vector field, anygeomagnetic vector is unique in the near-Earth space, and corresponds with longitude andlatitude. Therefore geomagnetic field can provide a natural coordinate to space flight,sailing and diving navigation. Some key technologies of geomagnetic navigation have beenresearched in this paper in the background of international science and technologycooperation project. It contains principle of optical pumping cesium magnetometer, carrierdegaussing technology in geomagnetic navigation and the technology of carrier matchingmagnetometer. There are three major aspects in research:1、 In order to get the best matching points between magnetometer and underwatervehicle. In the paper geomagnetic values in local area is measured, and the geomagnetic mapis reconstructed by Kriging. The experiment underwater carrier impacting magnetic fieldaround is finished in the flat area of the magnetic map. It turned out that the magnetic fieldchanged significantly in the selected space in cases of placing and not placing underwatercarrier. The difference in the same location can be up to2500nT. Thus it can be seen the ownmagnetic influence of underwater carrier must be considered when underwater magnetic fieldbe measured. We did8orientation magnetic tests with carrier in8planes of space for thereason, and analyzed the data by means of correlation coefficient. Finally the best point ofcesium magnetometer matching with the underwater carrier.2、It is common that using the wrapping coils to degauss the vehicle and belong to hardcompensation. This process is trival and equipments are complex. In this paper, it is based onsoft compensation. The magnetic survey experiment that underwater carrier rotates360degrees underwater has been done on this basis, and the effect of underwater carrier oncesium magnetometer in different heading is analyzed. The degaussing algorithm for ownmagnetic field of carrier is obtained and the real value of underwater magnetic field can berestored. It is the solid foundation of high precision underwater geomagnetic navigation andestablishing the underwater geomagnetic map.3、The formation process of Zeeman sublevels when Zeeman effect occurred in magnetic field is analyzed, then the theoretical analysis and the system design of laser optical pumpingcesium magnetometer sensor and gradient measurement theory are shown. The time evolutionprocess of the population in laser-pumped cesium atomic Zeeman sublevels when is detailedexplained using the Schrodinger equation and the optical Bloch equation. It can be found thatthe atom is doing Larmor precession in magnetic field while the distribution of state vector ineach Zeeman sublevel has cyclical change. The optical pumping will be affected and theabsorption of incident light will change significantly due to the population altering whendeviating from the initial time. Using the approximate form of the optical Bloch equations, therate equations of the populations in the cesium atomic Zeeman sublevels is analyzed andcalculated. Thus the time evolution functions of populations in levels of ground state andexcited state is obtained, and the operating principle of optical pumping cesium magnetometercan be explained by the quantum theory consequently.更多还原