International Service for the Geoid


Search in ISG Website




Services - Geoid Repository

Regional Models

Nairobi County - Kenya

  Authors: P.A. Odera, S.M. Musyoka, M.K. Gachari     Created: 2014    Resp: P.A. Odera  
      Status: PRIVATE    
A local geometric geoid covering Nairobi County and its environs has been determined by a geometric approach. Nineteen points levelled by both GPS and precise levelling techniques in the area of study have been used. Seven triangulation points have been used for the determination of transformation parameters between WGS84 and Arc-Datum1960 coordinates in order to express the local geoid height as a function of position. The geoid height is expressed as a function of the local plane coordinates through a biquadratic surface polynomial, using fourteen GPS/levelling points. Five points have been used for testing the results, showing a root mean square and standard deviation of about 1 cm in the area of study. This accuracy is sufficient for most engineering projects.

P.A. Odera, S.M. Musyoka, M.K. Gachari (2014). Practical application of the geometric geoid for heighting over Nairobi County and its Environs. Journal of Agriculture, Science and Technology, 16(2), pp. 175-185.

Web of Science ID: