The Study Of Matching Technology Between Cs Magnetometer And Vehicle

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.