The purpose of this work is to increase the accuracy, quality and information content of geodetic surveys of vertical steel tanks by using modern geodetic equipment and creating algorithms for data processing of these observations. Method. In order to increase the information content of data for straightening, it is proposed to calculate the geometric parameters of vertical steel tanks not only in places where data are directly obtained through instrumental observations, but also at any point of the 3D surface of the tank. The paper describes an algorithm for creating a 3D surface of a tank by bicubic spline interpolation (BSI). Results on the basis of the conducted research, it was established that the developed algorithm could be used and the 3D-surface spatial coordinates were determined. The method of determining the geometric parameters of vertical steel tanks by using BSI is improved. Scientific novelty and practical significance. Bicubic spline interpolation (BSI) was used for the first time. It greatly increases the accuracy and informality of the results of the control. The practical significance is confirmed by the control of the geometric parameters of a vertical cylindrical steel tank with a nominal capacity of 75.000 m3 with a floating roof and a double wall of the LODS “Brody” company.
Dimensions of biquadratic and bicubic spline spaces over hierarchical T-meshes
