Research On Quality Analysis And Correction Technology Of Geomagnetic Observation Data

Geomagnetic observation is the foundation of the research and development of geomagnetism.Its task is to record the variation of geomagnetic field with time and space continuously,completely and accurately.Due to the continuous variation of geomagnetic field and the wide bandwidth and large dynamic range of geomagnetic signal,the geomagnetic observation data will be interfered and influenced by many factors.Therefore,in order to accurately record the variation of geomagnetic field with time and space,we must improve the observation technology and improve the accuracy and quality of observation.The Fluxgate magnetometer has the advantages of small size,light weight,simple structure and high sensitivity.It has been widely used in magnetic observation stations for the relative observation of geomagnetic field.The current research shows that there are three main factors that affect the quality of the geomagnetic observation data.The first is the performance of the instrument itself.Because of the limitation of the processing level,it is difficult to ensure the absolute orthogonality of the three measuring axes of the instrument.The lattice value,temperature coefficient and the zero drift will also introduce the error.The second is the orientation azimuth and the horizontality of the base of the fluxgate magnetometer during the erection of the instrument.The third is the environment of observation.The change of temperature and the instability of the power supply system will be the main factors.In order to detect equipment failure and environmental disturbance in time,we usually set up two sets of the same type instruments in the geomagnetic observatory.In this paper,we take fluxgate magnetometer as an example.Firstly,we analysis of the quality,the current situation of the inconsistency and the correction technology of observation data.Secondly,through the measurement of the transfer function,the laboratory measurement of the performance and the quantitative analysis of the factors such as the lattice value and the temperature coefficient,we can determine the system characteristics of the instrument.Then,we will find out the influence of various factors on the fluxgate magnetometer during the actual observation process by analyzing the observation data.Finally,in view of the inconsistency of the recording curves of two sets of fluxgate magnetometers at various stations and the inconsistent error of the recording curve introduced by the azimuth and the lattice values of the instrument,we construct the correction model and solve it by genetic algorithm.Then,we correct the inconsistent data by the vector regression.In this paper,the system characteristics of fluxgate magnetometer are analyzed by the derivation of the transfer function and the performance test of the instrument.At the same time,the influence of the factors on the recorded data is analyzed quantitatively,and the calibration technique based on the genetic algorithm is put forward according to the law of the influence of the lattice value and the azimuth.Then,we conduct experiments at geomagnetic station and the results show that the precision of the lattice value is better than 0.002 and that of the attitude angle is better than 0.15?.The vector regression in standard coordinate system can be completed by the data reconciliation method in this paper,and the error is less than 0.5n T.At the end of the paper,the work of this paper and the further research is summarized.