The accuracy of defining the rectangular coordinate data when using the Global Navigation Satellite Systems has been constantly increasing, but it is necessary to represent the location of the points on the Earth’s surface within the geodesic coordinate data system in numerous appendices. Along with this the increasing measurements accuracy involves the necessity to raise the calculations accuracy. The necessity to solve the fourth degree equation is a peculiarity of the task to recalculate some space rectangular coordinate data into some geodesic ones. And in this case the complexity of the task to recalculate the coordinate data is explained by the complexity of solving the last problem. Some iteration methods used to solve it enable our calculating the data with any accuracy required but it is the calculation complexity of the methods used that might be questioned. This paper offers a study of some already existing variants and suggests some new ways to use iteration algorithms for recalculating some space rect­angular coordinate data into some geodesic coordinate data (latitude and longitude) and the height above the ellipsoid ; the accuracy and calculating efficiency of the iteration algorithms offered here results from the application of some wavy iteration process. It has been demonstrated that there is a possibility to lead the given task of recalculating some coordinate data to another problem which is entirely different from it.