Evaluation of Accuracy of the Geodetic Reference Systems for the Modelling of Normal Gravity Fields of Nigeria

Abstract

The normal gravity fields of Nigeria have been modeled exploiting the Geodetic Reference System 1930 (GRS-30), Geodetic reference system 1967 (GRS-1967) and the world geodetic reference system 1984 (WGS-84). The determination of the normal gravity fields from the three Geodetic Reference Systems were carried out to evaluate the accuracy of one reference datum with respect to another. Descriptive statistics of the normal gravity field values modeled on regional and local scales showed a large difference ( mGal 11 . 16 ) between the 1930 reference earth model (GRS-30) and 1967 reference earth model (GRS-67). A large difference was also established between the 1930 and 1984 reference earth models. The large difference in the mean of normal gravity field is attributed to error inherent in the Potsdam value ( mGal