Approximate Analytical Methods for Calculation of Spatial Position of Objects Conceming Terrestrial Ellipsoid

The solution of many technical tasks is connected with a need of calculation of various objects height over a surface of a terrestrial ellipsoid and their distance along the Earth's surface from the observer to objects with known coordinates. It is known that generally these tasks have no simple analytical decisions (as in the case of spherical Earth) and demand implementation of the numerical iterative algorithm that is rather costly on time. However, of ten there is no need to solve these problems absolutely precisely. In our work the approximate algorithm of calculation based on analytical formulas is constructed and comparison with a numerical algorithm is carried out. Being easy and fast in realization, our algorithm provides the accuracy rather high for many practical applications. The analytical formula of exact calculation of geodetic width of an object for its geocentric orthogonal coordinates is received for the first time.