重力场向下延拓的三阶Adams-Bashforth公式法

发布时间：2018-06-06 07:54

本文选题：重力场下延 + 垂向导数　；参考：《吉林大学学报(地球科学版)》2017年05期

【摘要】：重力场向上延拓是稳定且收敛的过程,而向下延拓是不稳定且发散的过程。为此,本文提出一种重力场向下延拓新方法。首先,对重力场及其垂向一阶导数向上延拓,得到不同高度的重力场垂向导数;然后,基于求解微分方程的三阶Adams-Bashforth多步法,推导出稳定的向下延拓公式;最后,为验证本文方法,将其分别应用于模型数据和实际数据。理论模型试验及误差曲线表明,相对于经典下延方法——傅里叶变换下延法和积分迭代下延法,新方法三阶Adams-Bashforth公式法下延过程稳定,边界效应不明显,下延深度可达5倍点距,下延结果与真实值的相对误差更小,结果更准确。将本文方法应用于加拿大某区实测航空重力数据,得到有效且准确的下延结果,能够识别和圈定一些细小异常特征。
[Abstract]:The upward continuation of gravity field is a stable and convergent process, while the downward continuation process is unstable and divergent. Therefore, a new downward continuation method of gravity field is proposed. Firstly, the vertical guide number of gravity field with different heights is obtained by extending the gravity field and its vertical first order derivative upward. Then, based on the three-order Adams-Bashforth multistep method for solving differential equations, a stable downward continuation formula is derived. In order to verify this method, it is applied to model data and actual data respectively. Theoretical model tests and error curves show that compared with the classical downward continuation method, Fourier transform downscaling method and the integral iterative downward continuation method, the third-order Adams-Bashforth formula method is stable, the boundary effect is not obvious, and the depth of the downward extension is up to 5 times. The relative error between the downscaling result and the real value is smaller and the result is more accurate. The proposed method is applied to the airborne gravity data measured in a certain area of Canada, and the effective and accurate downscaling results are obtained, which can identify and delineate some small anomaly features.
【作者单位】：吉林大学地球探测科学与技术学院;国防科学技术大学机电工程与自动化学院;浙江大学地球科学学院;武警黄金部队第二支队;
【基金】：国家深部探测技术与实验研究专项项目SinoPrbe-09-01(201311192) 国家高技术研究发展计划(“863”计划)项目(2014AA06A613)~~
【分类号】：P631.1

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