近日，中国地震局地震研究所谈洪波团队研究了垂直重力梯度模拟及其对重力基准面传递的影响。该项研究成果发表在2025年11月13日出版的《大地测量与地球动力学》杂志上。

过去，在重力数据处理中，通常使用-308.6 × 10^-8 s^-2的自由空气梯度作为测量点的垂直重力梯度，但这导致了仪器高程改正的不准确。为探究使用垂直重力梯度所带来的影响，研究组利用数字高程模型（DEM）和WGM2012重力异常数据，计算了大别山金寨基线场的理论重力梯度，并将平差结果与使用自由空气梯度得到的结果进行了比较。结果显示，采用理论计算的垂直重力梯度进行改正，使尺度因子的校准精度平均提高了0.00007。在不同基准控制下，重力平差结果的平均精度从2.23 × 10^-8 m/s²提升至1.45 × 10^-8 m/s²。

在单基准控制平差中，实际垂直重力梯度对基准传递的最大影响为8.7 × 10^-8 m/s²；而若不采用实际梯度（即使用自由空气梯度），其引入的误差则低至9.0 × 10^-8 m/s²，高至27.5 × 10^-8 m/s²。在多基准系统中，采用实际垂直重力梯度能获得最佳结果。即便是在三基准控制平差中，自由空气梯度改正对结果产生的平均影响也达到了3.9 × 10?? m/s²。因此，在重力数据处理中引入实测或理论计算的垂直重力梯度，对于显著提升其准确度和精度至关重要。

附：英文原文

Title: Vertical gravity gradient modeling and its influence on gravity datum transfer

Author: Hongbo Tan a

Issue&Volume: 2025/11/13

Abstract: In the past, the free-air gradient 308.6 × 108 s2 was used as the vertical gravity gradient of the measuring point in gravity data processing, which resulted in inaccurate instrument height corrections. To investigate the influence of using the vertical gravity gradient, theoretical gradients of the Jinzhai baseline field in the Dabie Mountains were calculated using DEM data and WGM2012 gravity anomaly data. Adjustment results were compared with those using the free-air gradient. Using the theoretically calculated vertical gravity gradient correction improved the scale factor calibration precision by an average of 0.00007. The average precision of gravity adjustment results under different datum controls increased from 2.23 × 108 m/s2 to 1.45 × 108 m/s2. In a single-datum control adjustment, the maximum effect of the actual vertical gravity gradient on datum transfer is 8.7 × 108 m/s2, while the effect without it is as low as 9.0 × 108 m/s2 and as high as 27.5 × 108 m/s2. In a multi-datum system, using the actual vertical gravity gradient yields the best results. Even with the three-datum control adjustment, the average effect of the free-air gradient correction on the results reaches 3.9 × 108 m/s2. Therefore, incorporating measured or theoretically calculated vertical gravity gradients into gravity data processing is essential for significantly enhancing its accuracy and precision.

DOI: 10.1016/j.geog.2025.09.006

Source: https://www.sciencedirect.com/science/article/pii/S1674984725000886