在物理大地测量研究中，大地边值问题一直是非常重要的研究内容。从1849年英国科学家Stokes解算了大地边值问题以来，人们一直在探索更完善、更准确的边值问题理论，从而出现最具有代表性的Stokes理论和Molodensky理论。随着科技的进步，尤其是GPS技术的出现，为物理大地测量学科的发展注入了新的活力，GPS/重力边值问题应运而生。我们完全可以利用其优势确定更为精确的（似）大地水准面，进一步为利用GPS代替传统耗时费力的水准测量创造条件。同时GPS/重力边值问题的全球区域特征，为我们解决高程基准不统一这个世界性问题提供了现实的可能性。

本文系统研究了GPS/重力边值问题。首先从理论上论述了该问题的数学特征，推导了多种解式或表达。同时给出了其在顾及地球扁率平方量级相对误差的椭球改正公式。其次论述利用GPS/重力边值问题在（似）大地水准面确定中详细计算方案，给出了一些在实用计算中的关键技术和Hotine积分中的奇异点处理方法。对扰动重力进行了重新定义，指出了利用DTM数据的GPS/重力边值问题优点所在。最后进行了实际数据验证。验证结果表明，利用GPS/重力边值问题确定的（似）大地水准面都达到了厘米级精度。同时验证了利用DTM数据的GPS/重力边值问题具有有效性和可行性。

本文首次提出了利用GPS/重力边值问题统一全球高程基准的理论。在利用GPS/重力边值问题求解似大地水准面时，并不需要高程信息。因此在一定意义上讲，GPS/重力边值问题求解的似大地水准面具有全球区域特征，这为全球高程基准存在的问题提供了统一的参考基准。利用深圳和香港的数据对该理论进行了验证，与水准联测的结果相互验证表明，该方法具有非常高的精度和实用价值。同时本文利用位理论知识推导出不同高程基准和不同高程系统之间相互转化的严密理论公式，对实际生产生活具有非常重要的现实意义

In physical geodesy, the geodetic boundary value problem (BVP) is one of very important research contents. Since the English scientist called Stokes solved the third geodetic BVP, people have been searching more perfect and accurate theories of geodetic BVP. Stokes and Molodensky theory are two kinds representative theory. With the development of science and technology, especially appearance of GPS, physical geodesy has been changed fundamentally, and then GPS/gravity BVP has been put forward. Using advantages of GPS/gravity BVP to compute more accurate quasi-geoid, it will provide good conditions for GPS measurement replacing spirit leveling. Meanwhile, GPS/gravity BVP has characteristics of globalization, which offers feasibility to unify global height datum.

In the dissertation, GPS/gravity BVP has been researched systematically. Firstly, we analyse mathematic characteristics of GPS/gravity BVP and deduce its solutions and practical expression. At the same time, the GPS/gravity BVP solution considering magnitude of flattening square is presented. Secondly, we bring forward very detailed program, key technology and the treatment method of Hotine Singular integral in geoid computation. Disturbing gravity is refined and GPS/gravity BVP using DTM data is advanced. At last, we validate the theory above by actual measurement data. The results show that the geoids computed by GPS/gravity BVP reach centimeter level, and GPS/gravity BVP using DTM data has feasibility.

A method of height datum unification using GPS and gravity data is put forward for the first time. As we all know, quasi-geoid computed by GPS/gravity BVP need not any leveling information. In a sense, the quasi-geoid calculated by GPS/gravity BVP provides global unified reference datum for different height datums. Then using Hong Kong and Shenzhen’s GPS, gravity and leveling data, we have done computations to check the new method. The computation result is coincident with the leveling connection result. This means that the new method has a great practical value. Besides, the transformation formulas among different height datums and different height systems have been deduced rigorously in the dissertation, which is very significant for practical production and living