The main objective of this study is to review and evaluate three common interpolation methods namely: Inverse Distance Weighting (IDW), Radial Basis Function (RBF) and Ordinary Kriging (OK), and generate maps of soil pH using these methods. The accuracy and efficiency of the generated maps have been examined as well as the most fitting technique for estimating spatial distribution of soil pH in the study area is identified. Studies were conducted within the limits of land use of RUP “Uchkhoz BGSHA” (Republic of Belarus, Mogilev region, Goretsky district). The total area of the surveyed territory is 3197.89 hectares. For the analysis data is used about pHKCl of soil solution obtained from materials of an agrochemical survey executed in 2014. Forecasting and visualization of the spatial distribution of pH sub(KCl) was carried out using the Geostatistical Analyst module of the ArcGIS software. The experimental anisotropic variograms were calculated to determine the possible spatial structure of soil pH. Based on cross-validation results, a polynomial function was identified as the best variogram model. The model created by the method of radial basis functions turned out to be the most suitable for forecasting purposes (the value of the root-mean-square error was 0.763). In terms of interpolation accuracy, the investigated deterministic and geostatistical methods are located in the next descending row: RBF greater than IDW greater than OK.

Some tasks require identification of landmarks in districts beyond the reach of existing optical observation facilities. The accuracy of their determination significantly affects the effectiveness of the use necessary equipment during the task. In the paper an algorithm to determine the object parameters using a flying platform is offered. An observation point is installed which is equipped with a navigation system to solve this task. This ensures its orientation and positioning. From the observation point an aerial observation point is displayed. It is suggested to use a flying platform. The coordinates of the flying platform are determined relative to the observation point; the coordinates of the landmarks are determined relative to the flying platform. The mathematical model of the estimation error determination of object coordinates with the help of a flying platform is proposed. The analysis of errors in determining the parameters of the object using a flying platform is conducted. Analysis of the results of mathematical modelling is conducted using the package of applications Mathcad. The dependence of these parameters on the relative position of the observation point, platforms and object is examined. It is shown that the main contribution to the error of determining the coordinates of the landmark is given by the errors of determining the observation point location and measuring the range. An analytical correlation is obtained, which allows to estimate the errors of determining the coordinates of the landmark using the flying platform with known errors in determining the observation point coordinates and the range determination of the range finder.

For millennia, the geodesic industry has improved methods and technologies for obtaining information on the location of objects on the Earth's surface, whose key task has been to improve the accuracy and reliability of measurements. At the same time, in recent decades, the rapid development of positioning technologies based on satellite radio navigation systems has created prerequisites for a situation where the acceptable accuracy of determining the geodetic characteristics of real estate becomes quite affordable even when using non-specialized geodetic equipment, including personal mobile devices. The article shows that the error in determining the area of land for registration of rights to real estate has its own “costˮ, which depends on the value of real estate in the area of survey. By the example of model sites, it is shown that further improvement of the accuracy of engineering surveying to determine the spatial characteristics of real estate objects would be economically feasible only if the cost of geodetic surveys (including the cost of purchasing new geodetic equipment, payment for labour of specially trained engineers, additional technical services and etc.) will not exceed the “cost of errorˮ to determine the area of the site. Using the example of Ukraine, it is shown that the most accurate geodetic surveys (determining turning points of land borders with an accuracy of more than 0.02 m) are economically feasible only when the market value of a land plot exceeds USD 208 per square meter.