亚洲MAGSAT卫星磁异常冠谐分析

根据亚洲地区（15°S-60°N，55°E-160°E）MAGSAT卫星碰异常1°×1°网格值，使用冠谐分析方法，计算亚洲地区卫星磁异常的冠谐模型．球冠极点位于22°N，108°E；球冠半角为50°．该模型的最大截断指数Kmax=20，共有441个系数．根据冠谐模型，绘制卫星平均高度（400km）以及其他高度（300km和500km）的理论卫星磁异常图（△X，△Y，△Z）．卫星磁异常的冠谐模型能表示磁异常的三维结构，为探讨岩石层结构提供证据．

SPHERICAL CAP HARMONIC ANALYSIS OF MAGSAT MAGNETIC ANOMALIES OVER ASIA

Based on the 1° × 1° grid values of the MAGSAT data over Asia （betweenlatitudes 15° S and 60° N, longitudes 55° E and 160° E）, using the method ofspherical cap harmonic analysis, a spherical cap harmonic model of the satellitemagnehc anomalies has been derived. The pole of the cap is at 22° N and 108° E,its half--angle is 50°. The maximum index （Kmax） of the model is 20, the total of themodel coefficients is 441. The maximum spherical harmonic degree corresponding tothes index is 36.4, giving a minimum wavelength, at the Earth's surface, of 1100km.The RMS deviations between the calculated and observed values are 1.33nT for △Xl.61nT for △ Y and 1 .51uT for △Z, respectively.According to the spherical cap harmonicc model, the satellite magnetic anomaly maps for△X △Y and △Z （altitudes are 300km, 400km, 500km, tespectively） were drawn. The sphericalcap harmonic model of the anomaly field can describe the three-dimensional sttructure The spherical cap harmonic models with different Kmax valeds are calculated, thesemodels can provide some fresh evidents for researeching the lithocperic structureo.