Long and short-term changes of Keplerian elements and correction coefficients of GPS satellites

413-418In satellite geodesy, the motion of artificial satellites has a crucial importance and the satellite’s position is the core point in the geodetic network. The simplicity of the broadcast ephemeris model directly determines the rate and efficiency of real-time navigation and positioning. GNSS broadcast message is transmitted in ECEF system either (GLONASS) or are Keplerian-like orbital elements (GPS, BeiDou, Galileo). The main aim of this paper is to describe the magnitude of Keplerian elements and correction coefficients of the navigational satellite changes based on a GPS satellite. The author examines six Keplerian elements and six correction coefficients for three different intervals: 2-hour, 1-day and 5-day intervals for periods of 9 days, a year and 10 years respectively. The analysis shows the varying behaviour of the time-series of the analysed components on the basis of the on-board GPS message, both random-like and repetitive (seasonal) trajectory time series

The applications of GNSS systems in logistics

The development of navigation satellite systems allows them to be used in many areas of trade, services and industry. This development is strongly visible in industries related to logistics and transportation where car navigation is becoming a standard for all kinds of vehicles. In this paper the author discusses navigation satellite systems, the princi-ple of their operation and presents analysis of possible applications in businesses related to logistics and transport.The development of navigation satellite systems allows them to be used in many areas of trade, services and industry. This development is strongly visible in industries related to logistics and transportation where car navigation is becoming a standard for all kinds of vehicles. In this paper the author discusses navigation satellite systems, the princi-ple of their operation and presents analysis of possible applications in businesses related to logistics and transport

GPS-only, GLONASS-only and Combined GPS+GLONASS Absolute Positioning under Different Sky View Conditions

In recent years GNSS measurements techniques obtained a majority role in civil engineering and other technical fields. An example of this is the monitoring of both natural phenomena and manmade constructions. The main advantages of satellite positioning, as opposite to classical surveying techniques like levelling or total stations, are continuous long term observations and economic advantage, due to the lack of measurement crew. Currently, apart from GPS, other satellite systems in use like GLONASS or Galileo are becoming more important. Together with development of GNSS measurements for satellite positioning in open areas, also urban and mountainous areas can be measured. This kind of areas was excluded from measurements with single GNSS system, due to the lack of the required minimum number of visible satellites. Multi-GNSS (hybrid, integrated - usage of more than one satellite navigation system in measurements) positioning, currently providing more than 80 active satellites, opens new grounds for satellite measurements. Among measurement methods PPP is the most developing one since the beginning of 21st century. Main PPP advantages are: independence from reference station, lack of limitation of use to certain areas and global coverage with consistent, homogenous solutions. The paper shows the results of 90-days continuous static observations processed with the usage of PPP technique on simulated different sky view conditions. Measurements were made on points with known coordinates as a construction simulation. The data were processed in three modes: GPS-only, GLONASS-only and hybrid GNSS (GPS+GLONASS) using three different elevation cut-off angles. Accuracy analyses were carried out on the basis of final, daily EPN solutions at the observation time

Analysis of lung auscultatory phenomena using the Wigner-Ville Distribution

In this paper the authors will try to discuss the applicability of Wigner-Ville Distribution for the digital analysis of auscultatory sounds. First of all, thte issues related to computer aided diagnosis are presented. Next, the methodology of research is shown and subsequently, the types of sounds are described. Another element of this work is the presentation of issues related to the digital signal processing including the Short-Time Fourier Transform(STFT), Wigner-Ville Distribution (WVD), and its variation- Smoothed Wigner-Ville Distribution (SWVD). This paper summarizes the results obtained using STFT and SWVD, showing SWVD more useful to detect the type of auscultatory sounds

The problem of the modernisation of land and building register in Poland as exemplified by the village of Rejowiec

The right of ownership is the broadest and one of the most basic property rights, which allows the owner to use and dispose of possessions without the participation of third parties. Therefore, the process of modernising the land and building register (MLBR) is extremely important considering, for example, that the data contained in this register is the basis for the subsequent calculation of public-legal obligations associated with the owned property, such as taxes. According to the current legislation, the data collected in the land and building register (cadastre) on the type of land use in combination with the soil classification of agricultural and forest land, the use of the property, its purpose and other information, are the basis for determining the agricultural, forest and real estate taxes by the competent authority. In Poland, in most cases, we have to deal with a situation in which the data appearing in the register differs from the actual state. Municipal budgets suffer losses because of this, and owners of properties of similar area and value sometimes pay completely different taxes. In this paper, the authors show a practical example of MLBR and the problems existed with it

Socio-economic factors associated with house prices. Evidence based on key macroeconomic aggregates globally

The aim of this paper is to assess the association between macroeconomic factors and house prices in selected OECD countries. In this paper, authors describe selected socioeconomic factors, adapt a transparent methodology based on the OECD database and derive results shedding a light on the main drivers shaping the trends of the real estate prices. Two main economic aggregates, inflation and gross domestic product (GDP) were analysed for the OECD member and non-member countries for which complete data have been made available for the period of 1990-2020. The OECD provides data for 60 countries in total, out of which 38 are members of the organization. Nevertheless, due to missing observations in certain countries, the analysis was carried out in 19 of them. The aim of the study was to determine how GDP and inflation dynamics are correlated with changes in property prices. Among the analysed countries, Japan and South Africa could be distinguished as outliers in terms of inflation, whereas in the case of GDP, Italy, Japan, Ireland and Norway stood out. Additionally, 12 representative countries were described in detail. These countries comprised four groups of three countries divided across two dimensions: the first, based on the highest and the lowest correlation coefficient, and the second, based on the measure used to calculate the correlation coefficient (correlation of the house prices with GDP and correlation of the house price with inflation). On the basis of the analyses, it was shown that the association between GDP and house prices is stronger than that between inflation and house prices – in most cases, prices increased at a similar rate as GDP. A particularly high correlation between GDP and house prices was found for Norway, New Zealand and Sweden, indicating a potentially higher marginal housing consumption responsiveness to changes in housing wealth in these highly developed countries, characterised by particularly low housing transaction costs and efficient mortgage market. It was deduced that such characteristics lead to a higher wealth elasticity of demand for new houses

Određivanje lokalnog geoida pomoću GNSS-nivelmana primjenom uvjetnog izjednačenja s nepoznatim modelom

GNSS-Levelling geoid determination is defined as the mathematical relation between orthometric and ellipsoidal height. The local polynomial surface interpolation method is one of the most widely applied methods for GNSS-Levelling geoid determination. The basic solution of polynomial surface interpolation is based on the geoid undulation, the difference of orthometric and ellipsoidal height, including some undetectable measurement error. In this study, firstly, the1st, 2nd and 3rd degree polynomial surface were taken as the geoid surface to determine the appropriate polynomial degree for selected study area, Samsun province of Turkey, using ordinary least squares adjustment models. Then, the Conditional Adjustment with Unknown Model adjustment solutions are made for these real work data. At the end of application, the results were then compared to these models and some suggestions were made for future applications.Određivanje geoida pomoću GNSS-nivelmana definirano je kao matematički odnos između ortometrijske i elipsoidne visine. Metoda interpolacije polinomne površine jedna je od najšire primjenjivanih metoda za određivanje geoida GNSS-nivelmanom. Osnovno rješenje interpolacije polinomne površine temelji se na undulaciji geoida, razlici između ortometrijske i elipsoidne visine uključujući neke pogreške mjerenja koje se ne mogu otkriti. U ovoj studiji najprije su kao površina geoida uzete polinomne površine 1., 2. i 3. stupnja kako bi se odredio odgovarajući polinomni stupanj za odabrano područje proučavanja, Pokrajine Samsun u Turskoj, primjenom uobičajenog modela izjednačenja metodom najmanjih kvadrata. Zatim se rješenja izjednačenja izvode za dobivanje ovih stvarnih podataka. Na kraju primjene rezultati su bili uspoređeni s ovim modelima te su izrađeni prijedlozi za buduće primjene

Otkrivanje grubih pogrešaka uz pomoć robusnih točnih i brzih metoda regresije najmanjih kvadrata u transformaciji koordinata

Different terrestrial reference systems have been defined and used because of some practical and historical events in geodesy domain. The transition from one system to another requires the coordinate transformation. Helmert transformation is the most commonly used model for 2D networks. 2D Helmert transformation are defined by four transformation parameters and two common points in both coordinate systems provides a unique solution. To increase the reliability of the transformation parameters, redundant observations are generally used. In this case, the Least Squares (LS) is the most common method used to obtain the unique solution from redundant observations. However, outliers occur often in dataset and affect severely the results of LS. There are generally two approaches applied for outlier detection: classical outlier tests and robust methods. The most common robust methods are Least Absolute Deviation (L1), M-estimators, the Total Least Squares (TLS), Generalised M-estimators, the Least Median of Squares (LMS) and the Least Trimmed Squares (LTS). For the solution of the LTS method, there are exact and approximate solutions. In this study, 2D Helmert transformation parameters between ED50 and ITRF coordinates are estimated with the LS method including classical outlier test, exact LTS solution and Fast-LTS solution which is an approximate solution to compare outlier detection performances of the methods.Različiti terestrički referentni sustavi definirani su i korišteni zbog nekih praktičnih i povijesnih događaja u domeni geodezije. Prijelaz iz jednog sustava u drugi zahtijeva transformaciju koordinata. Helmertova transformacija najčešće je korištena kao model za 2D mreže. 2D Helmertova transformacija definirana je s četiri transformacijska parametra, a dvije zajedničke točke u oba koordinatna sustava daju jedinstveno rješenje. Kako bi se povećala pouzdanost parametara transformacije, obično se koriste redundantna opažanja. U ovom slučaju, najmanji kvadrati (LS) najčešća su metoda koja se koristi za dobivanje jedinstvenog rješenja iz redundantnih opažanja. Međutim, grube pogreške često se pojavljuju u skupu podataka i ozbiljno utječu na rezultate najmanjih kvadrata. Općenito se primjenjuju dva pristupa za otkrivanje grubih pogrešaka: klasično ispitivanje grubih pogrešaka i robusne metode. Najčešće robusne metode su najmanje apsolutno odstupanje (L1), M-procjenitelji, ukupni najmanji kvadrati (TLS), generalizirani M-procjenitelji, najmanji medijan kvadrata (LMS) i metoda regresije najmanjih kvadrata (LTS). Za rješavanje metode regresije najmanjih kvadrata postoje točna i približna rješenja. U ovoj studiji, parametri 2D Helmertove transformacije između ED50 i ITRF koordinata procjenjuju se LS metodom uključujući klasična ispitivanja grubih pogrešaka, točna LTS rješenja i brza LTS rješenja što je približno rješenje za usporedbu učinkovitosti metoda u otkrivanju grubih pogrešaka