关键词: GNSS, 高程测量, 高程异常, 拟合高程, 相对定位, 残差, 精度评定

Abstract: Aiming at the low accuracy of GNSS elevation survey in oil and gas field surface engineering，factors contributing the field survey errors when using satellite positioning technology are analyzed，and their attributes are briefly commented by describing GNSS static survey principle，GNSS dynamic survey principle and survey adjustment theory. With the help of the calculation principle for GNSS elevation conversion and the theory of survey error propagation，key error factors in the process of calculation are analyzed，and the empirical formula commonly used in oilfield survey engineering for elevation fitting is derived using the least-square method of mathematical inversion theory. Based on the experience in oil and gas field survey，and with relevant technical regulations referenced，measures for controlling error factors during survey are summarized. The source of GNSS elevation survey errors and their influence are verified through project cases，and the conclusions are analyzed. Views on the effectiveness and limitations of applying GNSS elevation survey to oil and gas fields are proposed to guide the smooth execution of similar jobs.

Key words: Global Navigation Satellite System （GNSS）, elevation survey, elevation anomaly; fitted elevation, relative positioning;residual error, accuracy assessment