山区区域重力测量中间层校正系数的确定

山区区域重力测量中,地形校正范围的选择需要大一些,才能较好的消除地形起伏造成的影响,远区的地形和中间层影响均应考虑地壳弯曲的影响。因而在进行远区校正时,不能以过测点的平面为标准,而应以过测点的球面为标准,因此,地形校正值将会有负值出现。在进行中间层校正时,应消除与地形校正最大半径范围一致的弯曲圆盘的影响,此影响不仅与盘的半径有关,而且与厚度有关。本文给出对应于不同校正半径和不同厚度弯曲圆盘的一套理论计算结果,用这些结果得到的与不同校正半径配套的中间层校正公式,可供直接查阅使用。

THE DETERMINATION OF STONE SLAB CORRECTIONCOEFFlCIENT IN REGIONAL GRAVITY MEASUREMENTOF MOUNTAIN AREAS

In regional gravity measurement of mountain areas, the area selected for topographic correction should be somewhat large so that the influence of to pographic relief might be eliminated to a satisfactory extent. When studying topography of the distant area and the stone-slab effect, one should take into account the crustal curvature. Therefore, in distant area correction, the sphe rical surface passing through the survey point, rather than the plane surface, should be adopted as the reference. As a result, negative topographic correc tion value may occur. In stone slab correction, the influence of the curved disc whose radius is consistent with the maximum radius of the topographic correction ought to be eliminated. This influence is related not only to the radius, but also to the thickness of the curved disc.In this paper, a set of theoretical calculations for different radii and thi cknesses of curved discs are given. With these calculations, the stone slab cor rection formulae corresponding to different correction radii are obtained, whi ch can be consulted directly.