Results
Parameters of the best fitting circles after least squares adjustment are shown in table 2. Adopted ±1mm tolerance level was reached within three iterations. The parameters of the best fitting circles after least squares adjustment was given in table 2. Small variances of the results clearly indicate the high accuracy levels maintained in the field procedure. The mean of the centres of the six circles around the base was the best probable value of the centre of the stupa, which is having following co-ordinates.
North co-ordinate of the centre = 1538.7017±0.05
East co-ordinate of the centre = 8315.1568±0.05
The height to the top of the spire from the Salapathala Maluwa is 73 m.
Table 2. Centre co-ordinates and the radius of each circle
Conclusion
The above results clearly show that the centre of the original dome was setout to an accuracy of ± 20 cm. These measurements are independent from the centre of the Koth Kerella. The centre of the Koth Kerella is approximately one meter south to the centre of the dome. Surprisingly the centre of the top of the ruined spire (Circle P) is within ±2cm to the computed coordinates of the centre. This procedure can be adopted to find out the original size of any other large monuments very accurately.
References
Dampegama, S.D.P.J., 1999. Interim Report of Abhayagiriya Stupa Survey Stage I
Smithers, J.G., Architectural Remains, Anuradhapura, Sri Lanka.
Urho A. Uotila , 1986. Notes On Adjustment Computations.
