Least Square Modification of Stokes Formulae with Additive Corrections Estimator for Klang Valley Geoid Modeling

Abstract

Klang Valley is a fast-growing area and its development shall be equivalent with precise measurements for a precise vertical reference. Thus, existing vertical reference with 3 centimetres (cm) is inadequate and processed with complicated remove-compute-restore (RCR) procedure. Apart from this, areas such as Klang Valley should better than one (1) centimetre level vertical reference. Meanwhile processing method for vertical reference should be simplified and easy tasking. Because of that, methodology for this study is by employing the least squares modification of Stokes formula with additive corrections (KTH). This approach fully uses anomalies rather than residuals which it is more complicated. At the same time, the additive corrections estimator introduced combining the direct and indirect computations method. Datasets used in this study were refined rigorously prior to the gridding scheme in cross validation, free air anomalies, as well as anomaly correction. The KTHKVGM2020 gravimetric and geometric geoid models are evaluated from the reference position using GNSS levelling. It found that KTHKVGM2020 Geoid model is better than one (1) centimetre for Klang Valley area with efficiency processing method. Therefore, the study is an essential in future to develop high-precision geoid model with efficient methods particular for urban and rapidly developing areas.