Local Geometric Geoid Models Parameters and Accuracy Determination Using Least Squares Technique

The absence of national local geoid model in some countries has led to the determination of local geoid model in various parts of those countries. Local geoid models are determined using the geometric and gravimetric methods amongst others. Using the geometric method requires fitting an interpolation surface to points of known geoidal undulations which requires the determination of the geometric geoid model parameters and its accuracy using least squares technique. Because of the rigorous as well as the matrix nature of the technique, researcher have been experiencing difficulty in its application for the determination of geometric geoid models’ parameters and their accuracy. This paper presents a detailed procedure for the determination of geometric geoid models’ parameters as well as their accuracy using least squares technique. The steps to be considered when applying the technique are enumerated in sequential order. The enumerated steps were also demonstrated with a numerical example.