1. Heilongjiang Institute of Geophysical and Geochemical Exploration, Bureau of Geology and Mineral Resource of Heilongjiang Province, Harbin 150036, China; 

 The measurement of airborne gravity gradient is affected by factors such as airflow in the flight area and aircraft acceleration, so it is necessary to select a height with weak anomaly for compensation flight. In order to evaluate the measurement effect of gradiometer and determine the compensation flight altitude, it is necessary to es? tablish the standard gradient fields of the corresponding altitudes as references. For this reason, the method of es? tablishing reference field by surface continuation and gradient transformation using ground gravity data is studied first, and the model verification is carried out. Then, using this method, the reference fields of an airborne gravity gradient test area in Jilin??Heilongjiang at the flight altitudes of precision test and compensation are established, and the feasibility of selecting the compensation flight altitude is determined. In addition, the gravity gradient field es? tablished by continuation and transformation is compared with the forward modeling field of undulating terrain. The results show that the reference fields established by the two methods can both be used to evaluate the measurement accuracy of the gradiometer and select the compensation flight altitude.