Evaluation Transformation Paramters BetweenWGS84 & Adindam Datums

Abstract

Almost all topographic mapping in Sudan is carried out using the Adindan (African) datum. However, recent positioning techniques , using Global Positioning System (GPS) , are extensively used to establish three dimensional coordinates of control stations. Such coordinates shall be based on the World Geodetic System (WGS 84). Therefore , the relation between the Adindan (local) and WGS84 systems must be precisely established in order to enable mapping and other survey activities to be carried out on the Adindan (local) system. In this research the transformation parameters between the two systems are calculated using the following models: 1. The Bursa – Wolf model. 2. The Moldoneskii – Badekas model. In addition the Bursa – Wolf model is used to compute the parameters of the projection coordinates of the two systems. In all cases , the general and observation equations methods of the least squares were used. The result obtained , i.e the (7) transformation parameters (Badekas Model) are checked by comparing the transformed coordinates with the known ones and the maximum descrepancies did not exceed (0.5m) for the first order points.