Research On The Magnetic Fluxgate Theodolite

The magnetic field is one of the inherent geophysical fields, which physical characteristics can be reflected mainly from geomagnetic observation data. The data brings important significance for basic study,such as solid geophysics,space physics,conductivity of earth's interior,geodynamics,space weatherology,seismology and so on. Further more, the observation data has been directly or indirectly applied in various field, for instance,geological exploration environmental monitoring,aircraft or ship navigation,wireless communication,natural disaster prediction, etc. It's closely tied to human life,national economy and national defense, especially to the research process of earthquake monitoring and prediction,which has received considerable attention in recent years. The basic task of geomagnetic observation is to obtain data that possess integrity,continuity,accuracy and reliability. In order to acquire more accurate and abundant observation data, large number of reliable equipment is in need, in particular, the DI instrument using for absolute observation of geomagnetic field.As DI instrument is a high-precision device, the maching operation is complex and difficult, there is only a few manufacturer and limit product supply. The domestic DI instrument faces with the following problems:low accuracy,unstable performance,basically in stop production and poor after-sales service; More than that, imported instrument is extremely expensive and has a long after-sales maintenance cycle. Of all, a GMDI-1 magnetic fluxgate theodolite with independent intellectual property rights has been designed so as to relieve lopsided supply and demand, together with higher stability and lower price. Then, it can meet the demand of domestic geomagnetic network and flow magnetic field measuring.First, the working principle of magnetic fluxgate theodolite is described in this paper, including the introduction to the observation principles and way of magnetic fluxgate theodolite; Principle analyzing and numerical calculating are done to all parts of the magnetic fluxgate detecting system; A mathematical deduction for reduce or eliminate the observation error effectively is given based on the non-magnetic theodolite observation error theory analysis.Then, by combining with the working principle of magnetic fluxgate theodolite and using results of existing research for reference, the complete machine design for GMDI-1 magnetic fluxgate theodolite is carried out, including three important parts: first, the design for fluxgate detecting system, mainly expound material selecting analog circuit and mechanism design of magnetic fluxgate sensor; second, how to select non-magnetic theodolite, in this part, the structure characteristic of every part is analyzed, the design requirement and the magnetic inspection standard is putting forward; third, the design for mechanical fixed part of magnetic fluxgate sensor, while the mechanical fixtures between sensor and the non-magnetic theodolite is stated in details, but also the Directional operation steps of the sensor.At last, both the detecting system of GMDI-1 magnetic fluxgate theodolite and non-magnetic theodolite is tested, comparative observation is conducted in ManZhouli using complete machine, while another using MINGEO DIM magnetic fluxgate theodolite previously working in LuoYang, the test results show that all the technical requirements of GMDI-1 magnetic fluxgate theodolite meet with what the design desired completely, especially, some index is much superior to the request. The testing results of complete machine can reache or even exceed the level of domestic similar products, compared to imported high-accuracy fluxgate magnetometer, part of the indexes reach its same level, however, the precision of non-magnetic remains to be futher improved.