Geocentric indian geodetic datum by astrogeodetic — gravimetric method using smoothened geoidal heights

The astrogeodetic—gravimetric method based on the principle of least—squares solution has been used to determine the geocentric Indian geodetic datum making use of the available nongeocentric astrogeodetic data and the gravimetric geocentric geoidal heights in the form of smoothened values. Everett's method of interpolation has been used to obtain the smoothened geoidal heights at the astrogeodetic stations in India from the available generalized values at 1°×1° corners. The values of the geoidal height and deflections of the vertical at the geodetic datum Kalianpur H.S. so obtained have the negligible difference from the values computed earlier by the same method using directly computed gravimetric geoidal heights at the astrogeodetic stations, indicating that the use of the interpolated values in the astrogeodetic—gravimetric method employed would be an economical approach of absolute orientation of a nongeocentric system if the gravimetric geoidal heights are available at 1°×1° corners in the area of interest.