| In the aeromagnetic survey, the magnetometer is loaded on the airplane to examine the magnetic field change of the underground ore body and the geologic body. But because of the existence of ferromagnetic material and metal material, additional magnetic field will inevitably function on the magnetometer, affecting the magnetic survey quantity and the performance of the magnetic instrument. On the airplane each kind of magnetic interference is far greater than the inherent radio noise interference of the magnetic survey instruments. Because the frequency of this kind of magnetic interference is within magnetometer's detection range, filter's method can't be applied and only compensation method can be used. The magnetic survey quality relies on precision of the magnetic compensation, even if the modern magnetometer sensitivity is high, without good magnetic compensation measure, its magnetic survey quality will not have the distinct enhancement, as a result, magnetometer's performance cannot display fully.According to the magnetic interference's type on the plane, the mathematical model of magnetic interference can be established. The model includes a series of coefficients, which are fixed when the airplane's instruments are fixed. The needed data obtained can infer magnetic compensation coefficient, and eliminates the disturbance caused by the airplane movement according to these coefficients. According to the airplane magnetic interference's mathematical model and the expression, the related data can be taken during compensation flight, and some known quantities can be established based on these data, so that each compensation coefficient can be obtained, and precise three components of the earth magnetic field in the examination process can be achieved. It's vital that the mathematical model be established and compensation coefficient be achieved.This article has mainly studied the type, the nature of the airplane magnetic interference, and has established three component magnetic compensation mathematical model; It has studied the concrete implementation method of the three component compensation; It has studied the compensation flight method and the achievement of experiment data, the solution of the compensation coefficient; Finally it obtained the very good result according to the experiment data, and has confirmed the feasibility of this compensating process, and carried on the appraisal to the compensation result. It obtained four direction flight quality factors.Regarding the compensation process involving the massive numerical calculus as well as the graphical display, this article used the Matlab programming to realize. Matlab is a set of high performance numerical calculus and the visualization mathematics software. The programming operation is completely consistent with human mentality and the way of expression. just likes with the To write programs with Matlab is like arranging the formula and getting the solution to a question on the calculation paper so that it is called the calculation paper type scientific algorithmic language. In the Matlab environment, to the questions needing answers, you only need to list the mathematical expression simply and its result then shows by the data or the graphic mode. Under the Matlab environment the programmer can also be transformed into executive routine which runs independently, namely, it can run independently in a computer that has not installed Matlab.What this article uses is to measure the earth magnetic interference, the soft compensation mentality. Comparing with the traditional hard compensation, the soft compensating process has the following merits: (1) The compensating process is simple ;(2) It's efficient. It may complete the compensation flight in several minutes, saving the flight time greatly; (3) It applies pure theory's mathematics solution and the compensation precision is decided completely by the numerical calculus precision, and does not have the compensating coil and linear circuit easily affected by the noise; (4) Compared with the method of calculating disturbance and compensating disturbance, earth magnetism measurement has the following merits: Earth magnetism is far bigger than magnetic interference, earth magnetism measurement is advantageous to the enhancement of the compensation precision.By using this method you can directly conduct the the magnetic survey data processes afterward, if you choose the appropriate computer, accelerating the data operation's speed, or simultaneously changing to the more effective programming language, may also apply the composed programmer to the real-time compensation of the magnetic survey data. Thus, you may directly see, during the flight process, the real-time data obtained by magnetometer and compensation data as well as output curve.The aeromagnetic survey is one efficacious device in the aviation physical prospecting. The aviation physical prospecting is an aviation geophysical prospecting method that combines all kinds of new technologies. It is characterized by high efficiency, swiftness, economy and economy. It is one physical prospecting method that through the special-purpose physical prospecting instrument equipped in the airplane which explores changes in all kinds of geophysics field in the navigation process, studies and seeks for the subsurface geology structure and the minerals. The aviation physical prospecting is characterized by high speed, no surface condition limit, the big area work precision, and normal performance in some complicated topographical conditions.In the aviation magnetism survey aspect, the development of aeromagnetic three component key technologies research is an important task which the country faces and one of the key technologies needs to study is magnetism vector compensating process technology. Since the Magnetic compensation work appeared, magnetic compensation has transformed gradually from the electronic compensation to the soft compensation and the compensation precision and the scope have been enhanced unceasingly through many years of development. Along with the computer computation speed and capacity increase, this tendency will become more and more obvious. Canada's AADC-â…¡, the aviation magnetism automatic digit compensation meter, the independently developed SC1 real-time aeromagnetic digit compensator of our country land resources aviation physical prospecting remote sensing center, as well as the newest DAARC500 aeromagnetic digit compensator are at present the most advanced magnetic compensation apparatus.But these instruments are compensation of the earth magnetism resultant field. The aeromagnetic three component measuring technique's research in domestic also just started. Overseas, many organizations have started development theory and the method study, and under the static condition, have developed to determine magnetism vector the magnetic flux portal type, the compensation type and the superconductivity type magnetometer, but the aeromagnetic three component surveys and magnetic compensation technology haven't been reported as a success. Therefore, the research of this article to the earth magnetic field three component compensation principles and the method is very significant in theory. This method could provide very good compensation precision, the research process and the result may provides certain reference experience for afterward research and application, and is very meaningful to the enhancement of the aeromagnetic measuring accuracy and further development of the aviation physical prospecting.
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