It is well known that the determination of the geoid model especially by the classical gravimetric approach is not a simple task. Consequently, an empirical method is often adopted for a small geographic area. This approach is especially useful because of its simplicity, accessibility to local surveyors, and its adequacy for many applications involving the conversion of World Geodetic System 1984 (WGS 84) GPS heights to a local height reference system based on the Mean Sea Level (MSL). This paper details the procedures and processes used to establish, validate, and consider the statistical significance of a predictive geoid model for a small geographic area. The model is based on data acquired within the central areas of the Port Harcourt metropolis in southern Nigeria. The MSL benchmark of the Nigerian Ports Authority (NPA) in Port Harcourt, which was established during the colonial administration, served as the reference datum.
SaLIS is a scientific journal devoted to reporting research and new work conducted to advance geodetic surveying, land surveying, large-scale mapping, and geographic information systems designed to advance the development and management of the cadastral parcel data layer and other land information applications. SaLIS publishes research articles, technical papers, technical notes, papers on the current state of surveying education, surveying history, book reviews, and current literature reviews. Every four years, the journal publishes the U.S. Report to the International Federation of Surveyors (FIG). The Proceedings of the Surveying Teachers Conference are published bi-annually.