数字图像技术在重力异常地形校正中的应用

DIGITAL IMAGE APPLICATION TO THE TOPOGRAPHY CORRECTION OF GRAVITY ANOMALY

通过对地形体及其密度信息数字图像化,利用计算机仿真能较精确地计算出地形体在任意一点的重力场强度。在重力异常地形校正时,用各测点的实测数据减去相应测点的地形体重力场强度,即得到地形改正和中间层改正后的重力场强度。这样,重力异常校正中的地形改正和中间层改正可一并完成,既简化了校正的工作步骤,又提高了准确性。通过地形体实例,分别用数字图像仿真计算和积分精确计算其重力场强度,结果表明,二者计算结果十分相近。用数字图像仿真计算地形体重力场强度,误差较小,准确性较高,该方法完全适合重力异常地形校正。

In gravity exploration,the middle layer and topography correction must be done in Bouguer gravity anomaly computation.The computation may,however, be inaccurate because of the irregular terrain.In this article,in order to simplify the topography correction,the authors have applied the digital image technology to the correction.Storing the shape and density information of the geological volume into digital image,we can use computer to calculate the gravitational field caused by the geological volume at any position.When the topography correction is conducted,one can use the measurement field value to minus the gravitational field caused by the geological volume at the measurement position,which is calculated by computer based on the digital images of geological volume.Therefore,the middle layer and topography corrections,as an all,will be processed simultaneously.The authors have given an example to testify the validity of the topography correction method.