Research On Terrain Correction Method Of Aerial Gamma Spectrum Measurement

Airborne gamma spectrometry is to install the airborne gamma spectrometer system on the aircraft or other aircraft,which is to measure the content of K,U,Th,and other radioactive elements.It is generally used in uranium exploration,radiation environment monitoring,nuclear emergency monitoring,and other fields.As an aerogeophysical method with high efficiency,convenient operation,a wide range of operation and high efficiency,airborne gamma spectrometry is suitable for large-scale work and limited by geographical conditions,but complex terrain will affect the accuracy of airborne gamma spectrometry,Therefore,a more accurate terrain correction method is needed to improve the accuracy of airborne gamma spectrum measurement.At present,the altitude correction is the main method in the airborne gamma spectrometry in China.Therefore,it is of great significance to carry out the technical work of topographic correction method for airborne gamma spectrometry.In this paper,the influence of terrain on the airborne gamma spectrum measurement and the shortcomings of the traditional height correction method are analyzed.Based on the airborne gamma spectrum measurement theory and the previous research results,the calculation formula of the intensity of the finite element airborne gamma spectrum measurement is derived,and the discrete integral terrain correction method is studied and realized.The method solves the problem of integration in complex terrain correction.The main research results are as follows:(1)Based on the distribution characteristics of the radiation field and the theory of airborne gamma spectrum measurement,the mathematical equations of static and dynamic airborne gamma spectrum measurement are established,and the influence of height and terrain on the results of airborne gamma spectrum measurement is analyzed.(2)The paper discretizes the surface and uses the discrete integration method to achieve the area correction and height correction in the measurement of aviation gamma spectroscopy.Method and calculate the correction coefficient of typical terrain.(3)The thesis studies the method of acquiring and using DEM data.Combined with the requirements of the terrain correction method,the DEM data is networked to obtain the elevation data grid,and the survey area terrain correction method is implemented using MATLAB software.(4)The thesis carried out terrain correction processing on the aerial gamma-ray spectrum data of a survey area and analyzed and verified the correctness of the terrain correction method through data comparison.The results show that the terrain correction method can largely eliminate the data anomalies caused by the terrain impact,thereby truly reflecting the anomalies of the ground radiation field.Due to the influence of time,this paper can not complete the processing of dynamic flight measurement data,further in-depth studies in this direction may be carried out in the future.