This article presents exact algorithm for calculation "length of tangent" to quadric surface based on results of measurement tangent directions to shell object. The considerations are mainly about one-sheet hyperboloid shape. The considerations made for the objects in the shape of hyperboloid of one sheet. Using the algorithm can calculate the location and shape, but also the parameters of the shell, which compared to previously used methods, allows for better precision than that calculated on the basis of previously existing algorithms. Modification of the algorithm presented allows to increase the accuracy of the final results, using the proposed method of measurement. This solution saves money and time. ...
On the base of geodetic, photogrammetric or radio observations of the sheet objects its position, dimensions and shape are determined. Approximation of mathematical model for the surface, used as a reference for estimation of geometric state of the object is based on the space co-ordinates of points representing the sheet of the object. In practice, the model parameter values are determined without consideration of accuracy of these co-ordinates. However, the covariance matrix for co-ordinates of observed points constitutes a base to estimate accuracy of determined parameters and its functions. In this paper an algorithm enabling es-timation of accuracy for the estimated parameters of the surface is presented. In addition, a measure of fitting of mathematical model to the observed geometric state of the sheet is determined. This parameter can be used to decide on adequacy of a medel. A method of estimation of the unit variance estimator reflecting effect of measurement errors only is also described. ...
