ADAM ŁYSZKOWICZ 1, ANNA BERNATOWICZ 2
1 Department of Air Navigation, Faculty of Navigation, Polish Air Force University
2 Department of Geodesy, Faculty of Civil Engineering, Environmental and Geodetic Science Koszalin University of Technology
ABSOLUTE SEA LEVEL CHANGES AT THE TIDE GAUGE STATION
IN WŁADYSŁAWOWO USING DIFFERENT TIME SERIES SOFTWARE PACKAGES
https://doi.org/10.23939/istcgcap2018.02.013
This paper presents geocentric sea level changes at the tide gauge station in Władysławowo, Poland. These changes have been calculated from the time series of GNSS and tide gauge observations. For the estimation of the geocentric sea level trend computer software packages Hector, GITSA, GGMatlab, and Statistica have been used. The results show that all the software packages give a similar value of absolute sea level changes in Władysławowo and it is estimated at a rate of around 3 mm/year. The examined computer programs are featured by a different degree of visualization and the simplicity of use. A significant difficulty is to prepare the required data format and the installation of the computer program in the software environment e.g. Matlab. Finally, it can be concluded that the Hector software package, due to the simplicity of input data preparation, that the possibility of on-line calculations and the selection of different error models are very useful for the analysis of time-series of geophysical phenomena like sea level changes. The least recommended for this type of analysis of time series is the Statistica software package.
Key words: mean sea level, tide gauge, satellite GNSS observations.
Література – 30.

UDC 528.2./.3
S. SAVCHUK1, N. KABLAK2, A. KHOPTAR1*
1 * Department of Higher Geodesy and Astronomy of National University Lviv Polytechnic, 12, S. Bandera str., Lviv, 79013, Ukraine, tel.:+38(093)1107822, e-mail: alina.a.khoptar@lpnu.ua
2 Department of Urban Construction and Management, Uzhhorod National University, Uzhhorod, 88000, Ukraine.
COMPARISON OF APPROACHES TO ZENITH TROPOSPHERIC DELAY DETERMINATION BASED ON DATA OF ATMOSPHERE RADIO SOUNDING
AND GNSS OBSERVATION
https://doi.org/10.23939/istcgcap2018.02.024
Currently, Global Navigation Satellite Systems (GNSS) are increasingly used in atmospheric monitoring tasks. To determine tropospheric delays, two approaches are most often used: the calculation of atmospheric radio sounding data and the processing of GNSS observations. GNSS processing is, generally, based on two methods, namely precise point positioning (PPP) and double-differencing (DD). PPP is a potent data analysis instrument sensitive to a variety of parameters. This paper demonstrates that PPP can be used not only for positioning and navigation but also for other atmospheric monitoring tasks. Purpose. Realization of a comparative analysis of various approaches for tropospheric delays determination based on the results of GNSS observations processing by the PPP and DD methods, and on atmospheric radio sounding data. Methodology. The observation data from following GNSS stations were used: BUCU (Bucharest, Romania), GANP (Ganovce, Slovakia) and GLSV (Kyiv, Ukraine), as well as, located nearby, aerological stations 15420 (Bucharest, Romania), 11952 (Poprad-Ganovce, Slovakia), 33345 (Kiev, Ukraine). Therefore, in this work the zenith tropospheric delay ( ) determination is performed according to GNSS observation data using the PPP method with the application of the software package GIPSY-OASIS and the DD method by means of the Bernese GNSS Software and GAMIT-GLOBK software packages. The obtained results were compared with the corresponding radio sounding data. Results. The values obtained using different approaches correspond to a sub-centimeter level of accuracy with respect to radio sounding data, while the best results were obtained by the PPP method at Slovak stations (millimeter level), where the distance between the location of the aerological and GNSS stations is less than 1 km, i.e. they are in the same atmospheric conditions. This suggests that the PPP method provides a better level of accuracy and can be used precisely to determine tropospheric delays. Scientific novelty, practical significance. The technology of continuous atmospheric monitoring using GNSS stations and observations processing technology from these stations based on the absolute positioning PPP. The obtained results after their completion can be used in thoughtful investigations of tropospheric effects through GNSS observations and for numberous atmospheric monitoring applications.
Key words: precise point positioning (PPP), zenith tropospheric delay ( ), atmospheric radio sounding, GNSS-observation, atmospheric monitoring.

Література – 20.

UDC 332.3: 528.44
YU. HUBAR, L. VINARCHYK
The Department of Cadaster of Territory of National University Lviv Polytechnic, 12, S. Bandera str., Lviv, 79013, Ukraine,
tel. +38 (032) 2582631, email: Yurii.P.Hubar@lpnu.ua
METHODS FOR THE DETERMINATION OF EXTERNAL OBSOLESCENCE
OF THE COMMERCIAL REAL ESTATE-CASE STUDY
https://doi.org/10.23939/istcgcap2018.02.047
The purpose of the study. Solving the problem of the calculation of aggregate obsolescence of a real estate object in general and external obsolescence in particular, as being less investigated and described in scientific papers is a topical issue. A topical issue being investigated and described in scientific papers is the problem of calculating the aggregate obsolescence of a real estate object, particularly its external obsolescence. The drawback of the existing methods of determining the external obsolescence (except a paired comparison method) is the necessity of storing a great amount of selling or renting data, which is rather difficult within Ukrainian market conditions. Current methods used for the investigation of external obsolescence of commercial real estate which require less data are proposed [ISA, 2017; NSA-1, 2003; NSA-2, 2004]. Methodology. In the process of real estate valuation obsolescence is considered to be an important factor for the valuation of buildings by the cost approach and is determined as sacrifice of utility or loss in value, due to several possible causes [Kharryson, 1994; Ekkert, 1997]. The subject of the investigation and analysis shows a potential gross revenue received from leasing; revenue losses from rental payments; the possibility of gain contingency; and transaction costs, that comprise net operating income. In this case they should serve as a market proof of the level of the rate of return of the real estate being evaluated. The results. Today the value of external obsolescence of the real estate is determined with the use of a large amount of market data. In general, the market comparison is a key position in determining aggregate improvements and depreciation and the aggregate depreciation is the difference between replacement or renewal costs and market improvement value, and depreciated cost of replacement of land improvements is a difference between the selling prices of real estate and market land value. The investigations related to the development of new methods of the estimation of the external obsolescence of real estate have been carried out. In the paper it is proven that for the improvement of the evaluating methodology of real estate and determining its external obsolescence new methods should be applied, which will allow the real estate evaluators to avoid subjectivity in calculations and, subsequently, “legal deficiency” in obtained results. Scientific innovation. Existing methods of valuation of the external obsolescence do not always meet modern market demands and it is necessary to develop new methods having certain advantages over the methods being widely used in practice. The introduction of new methods of calculating the external obsolescence of commercial real estate is important for improving the valuation methodology for modern real estate market of Ukraine. Its practical significance. The investigations enable obtaining the mathematical dependences for determining the correct and scientifically grounded coefficients of the external obsolescence for the commercial real estate property objects. It is feasible to apply the investigations represented in the paper for determining the external deterioration of commercial real estate with the purpose of the calculation of depreciated costs of replacement or depreciated costs with further calculation of its market value [Hubar, 2014, Perovich & Hubar, 2016].
Key words: aggregate obsolescence, external obsolescence, commercial real estate, valuation of real estate, price of liquidation, improvement, production volume.

Література – 17.