This study presents a software tool Grav3CH_inv developed to estimate the three-dimensional depth structure of sedimentary basins from their gravity data through an iterative process. The algorithm linked to the developed code operates recursively both in the wavenumber domain and in the space domain based on a triple method combination. The modelling strategy allows considerations of the model space with an exponential increase in density with depth and also with density variations in the horizontal direction. The accuracy of computation of gravity anomalies in the FFT-based forward procedure is also increased by using the shift-sampling technique which minimizes discretization effects during transformations between the space and wavenumber domains. Given the observed gravity anomalies and the density design of the basin, the iterative procedure performs automatically until the goodness of the fit between the observed and modeled anomaly, either the root-mean-square error or the largest error is below its pre-assigned value. As an advantage, the computing time is acceptably short for such a kind of an modelling problem. The GUI-enabled interactive control functions of the Grav3CH_inv code allow users to set optional settings, style of outputs and export formats, and facilitate operations without requiring coding expertise to perform the relevant procedures of the algorithm. The feasibility and accuracy of the proposed software is demonstrated by evaluating the synthetically produced gravity anomalies of various 3D basin models and also by analyzing an actual gravity data from the Los Angeles basin, California.

本研究提出了一种软件工具 Grav3CH_inv，该工具用于通过迭代过程根据沉积盆地的重力数据估计沉积盆地的三维深度结构。与开发代码相关联的算法基于三重方法组合在波数域和空间域中递归运行。建模策略允许考虑密度随深度呈指数增长以及水平方向上的密度变化的模型空间。通过使用位移采样技术，在基于 FFT 的前向过程中计算重力异常的精度也得到了提高，该技术最大限度地减少了空间域和波数域之间转换过程中的离散化效应。鉴于观测到的重力异常和盆地的密度设计，迭代过程会自动执行，直到观察到的异常与建模的异常之间的拟合良好，即均方根误差或最大误差低于其预先指定的值。作为优势，对于此类建模问题，计算时间短是可以接受的。Grav3CH_inv 代码的 GUI 交互控制功能允许用户设置可选设置、输出样式和导出格式，并方便操作，无需编码专业知识来执行算法的相关程序。通过评估各种 3D 盆地模型的综合产生的重力异常以及分析来自加利福尼亚州洛杉矶盆地的实际重力数据，证明了所提议软件的可行性和准确性。