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1

The stability of inter-system bias over time for positioning using GPS and Galileo

Kwaśniak Dawid, Cellmer Sławomir

GIS Odyssey Journal

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2024

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Vol. 4, no. 1

79--91

EN

The introduction of new overlapping signals from GPS and Galileo, such as L1 and E1 and L5 and E5a, presents new opportunities for enhanced precision and reliability in positioning. However, it also introduces new challenges that need to be addressed. One of the primary challenges in processing GPS and Galileo observations is the requirement for Inter-System Bias (ISB) handling. An important aspect has become the examination of the stability of the ISB parameter over time. Both short-term and long-term stability must be investigated. For this purpose, experiments were conducted on 20 permanent IGS stations in 10 pairs. Using the Modified Ambiguity Function Approach (MAFA) method, the stability of the ISB parameter over time was investigated, both for short-term (daily) and long-term periods. When selecting pairs, care was taken to ensure that the distances between the receivers in the pair were shorter than 10 kilometers. This allowed us to reduce the influence of the atmosphere on the obtained results. Observation data were obtained from the permanent GNSS stations mentioned above for 2020 and 2021. Calculations were conducted for the GPS and Galileo systems corresponding observations. The obtained results showed that for both the short-term period, which is a day, and for the more extended period of time (few months), the ISB exhibits significant stability. This means that once determined, the ISB can be used for several months for a given pair of receivers.

2

Synchronizacja i analiza przebiegu napięcia pobranego z sieci elektroenergetycznej

Witkowski Piotr, Dołęgowski Michał

Elektro Info

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2024

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nr 5

46--48

PL

W artykule opisano autorską metodę synchronizacji sygnałów elektroenergetycznych rejestrowanych w dwóch lokalizacjach. Następnie opisano sposób, w jaki obydwa przebiegi zostały ze sobą skorelowane, oraz sprawdzono poprawność dokonanej metody synchronizacji, skupiając się na analizie fazorów i ocenie jakości energii elektrycznej. Synchronizacja może być wykorzystywana podczas badań PMU (Phasor Management Unit), jednak obecnie znane metody działają tylko w miejscach, w których dociera sygnał GPS.

EN

The article describes an original method of synchronizing power signals recorded in two locations. Then, the method in which both waveforms were correlated was described, and the correctness of the synchronization method was checked, focusing on phasor analysis and power quality assessment. Synchronization can be used during PMU research, but currently known methods only work in places where the GPS signal reaches.

3

Converting Coordinates Between the Local Geodetic Reference and the Global Geodetic Reference for Selective Sites in Babil Province

Al-Saedi Ali Salah J., Shnewer Fadhil M., Falih Khaldoon T.

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 4

38--44

EN

A geodetic transformation is a mathematical operation that takes coordinates of a point in one coordinate system and returns the same coordinates in another coordinate system. This study aimed to show the compatibility between global positioning system coordinates and the local maps in Iraq; this compatibility will be made for locations in the Babil province. In the study area, fifteen control points have been chosen. GPS measures geographic and projected coordinates depending on the Universal Transverse Mercator projection and the World Geodetic System 1984 datum. In Iraq, the measured geographic coordinates are converted to projected coordinates using a geographic information system based on Clarke 1880 ellipsoid. To facilitate the conversion of the coordinates, both formulas and parameters are provided for any point in the study area between the two systems using a GPS receiver and the ArcGIS software. The present study shows that the differences in easting coordinates are about -287.630 m, while the differences in northing coordinates reach 278.525 m. It was concluded that the various datums might play a significant role in producing maps and updating those maps for engineering works.

4

The concept of determining ground speed with limited access to GNSS signal on UAV

Kochan Jakub, Ważny Mariusz, Falkowski Krzysztof

Aviation and Security Issues

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2024

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No. 1

41--51

EN

This article presents an innovative approach to navigation using image recognition in situations characterized by limited access to GNSS (Global Navigation Satellite System) signals (signal interference). The presented system relies on image processing to define the characteristic edges of random objects. Subsequently, the actual ground speed of the moving object (UAV) is obtained based on changes in the object’s position. The article aims to show the potential of image recognition in navigational systems. The actual ground speed obtained by the image recognition can be used to correct the inertial navigation system.

PL

Niniejszy artykuł prezentuje nowatorskie podejście do nawigacji z wykorzystaniem rozpoznania obrazu w sytuacjach charakteryzujących się ograniczonym dostępem do sygnału GNSS (zakłócenia sygnału). Zaprezentowany system opiera się na przetworzeniu obrazu w celu zdefiniowania charakterystycznych krawędzi obiektu. Następnie na podstawie zmian położenia obiektu wyznaczana jest prędkość rzeczywista poruszającego się BSP. Ponadto w artykule przedstawiono potencjał zastosowania rozpoznania obrazu w systemach nawigacyjnych. Wyznaczona prędkość z użyciem rozpoznania obrazu może być wykorzystana do korekcji inercjalnych systemów nawigacji.

5

Analysis of comparability of PCV in surveying-grade GNSS antenna - Topcon HIPER-VR case study

Baryła Radosław, Dawidowicz Karol

Artificial Satellites : Journal of Planetary Geodesy

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2024

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Vol. 59, No. 3

87--99

EN

It is well known that the phase center of a Global Navigation Satellite System (GNSS) antenna is not a stable point. For any given GNSS antenna, the phase center will change with the direction of the incoming signal from a satellite, as well as the frequency. Ignoring these phase center variations (PCVs) in GNSS data processing can lead to notable errors, especially in vertical position component determination. To avoid the problem, antenna PCV together with the phase center offset (PCO) information are recommended to be used in GNSS observation processing. We currently distinguish between individual and type-mean phase center correction (PCC) models. These models describe the variations in the phase center of the antenna as a function of the elevation angle and azimuth. In general, the primary difference between individual and type-mean models lies in their specificity. Individual models are highly precise but are valid only for a particular antenna model, while the type-mean models are more general and can be applied to a broad range of antennas of the same type, but may suffer from a lower level of precision. This paper aims to analyze the comparability of PCV in surveyinggrade GNSS antennas. For the analyses, we propose to use an originally designed bench with precisely defined relative positions of the seven antenna mounting points. Preliminary studies have been performed using GPS observations on L1 and L2 frequencies recorded by seven Topcon HIPER-VR antennas. The results proved that the comparability of PCV for this antenna is high. The position error did not exceed 3 mm. It could be assumed that the type-mean PCC model could describe PCV all antennas of this type with good accuracy.

6

Improving positioning accuracy of aircraft using SPP method in GLONASS system

Krasuski Kamil, Ciećko Adam, Grunwald Grzegorz, Kirschenstein Małgorzata

Archives of Transport

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2024

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Vol. 69, iss. 1

21--37

EN

The paper presents the results of a study showing the accuracy of the determination of aircraft position coordinates based on the SPP (Single Point Positioning) solution in the GLONASS (Globalnaja Navigatsionnaya Sputnikovaya Sistema) system. For this purpose, the paper develops and implements an algorithm for the correction of position errors as parameters describing positioning accuracy. The proposed algorithm uses position error values determined for a single GNSS (Global Navigation Satellite Systems) receiver, which are joined in a linear combination to deter-mine the positioning accuracy of the aircraft. The algorithm uses linear coefficients as an inverse function of the number of GLONASS satellites being tracked by the GNSS receiver. The developed algorithm was tested for GLONASS satellite data recorded by Topcon HiPer Pro and Javad Alpha geodetic receivers, during a flight test carried out with a Cessna 172 aircraft around the military airport in Dęblin. Navigation calculations were carried out using RTKLIB v.2.4.3 and Scilab v.6.0.0 software. On the basis of the tests carried out, it was found that for single Topcon HiPer Pro and Javad Alpha receivers, position errors were up to ±11.4 m. However, by using the position error correction algo-rithm for both receivers, GLONASS positioning accuracy is up to ±3.6 m. The developed algorithm reduces position errors by 60-80% for all BLh (B-Latitude, L-Longitude, h-ellipsoidal height) coordinates. The paper shows the possibility of testing and implementing the proposed mathematical algorithm for the SPP solution in a GPS (GlobalPositioning System) navigation system. In this case the position errors from the GPS SPP solution range from -0.9 m to +0.9 m for all BLh coordinates. The obtained results showed that application the GLONASS and GPS system in air transport is important. The algorithm used in this work can also be applied to other global GNSS navigation systems (e.g. Galileo (European Navigation Satellite system) or BeiDou (Chinese Navigation Satellite System)) in air transport and navigation.

7

Analysis of seasonal crustal deformation characteristics in Dali, Yunnan using GPS observations

Shen Xing, Liu Xikang, Shen Yu, Song Chengke, Yin Haiquan, Chen Zhaohui

Acta Geophysica

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2024

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Vol. 72, no. 3

1473--1482

EN

This paper extracts and separates seasonal term of GPS (Global Positioning System) time series based on empirical mode decomposition and wavelet transformation. Through time series analysis of 9 GPS continuous stations in Dali, Yunnan, it is found that the vertical (U), north-south (N) and east-west (E) components of the relative motion have distinct annual and semi-annual period components. In the vertical direction, the U component has the strongest seasonal deformation characteristics, on the annual period term, between each station the correlation coefficient reaches 0.98, this is consistent with the relevant research results of many researchers; In horizontal direction, seasonal deformation is also more significant, the N component annual and semi-annual period signals are more obvious and the correlation coefficient is high, but the E component 9 stations signal are relatively scattered and poorly correlated. On the semi-annual period, the N and U directions have a very obvious and consistent semi-annual periodicity, and their two correlation coefficient numbers are 0.95 and 0.94 on average, respectively, the N and E are negatively correlated with a correlation coefficient of -0.98. In time series trend term, 9 stations show southeast movement in horizontal direction, but have great differences in vertical movement trend. Among them, YNLJ, YNYS, YNSD and YNLC are linear uplift movement with good consistency. YNYA, YNCX and YNJD show overall uplift movement, but with subsidence fluctuation, the trend of the three stations is very similar, with an average correlation coefficient reaches 0.8; XIAG station shows uplift movement as a whole, the relative motion trend in the E direction is very different from other stations in phase and amplitude, probably because it is closer to the Erhai lake and more susceptible to the influence of water level changes; YNYL also has different motion changes at different times, but the overall performance is subsidence motion. The analysis suggests that the GPS time series contains rich information on the seasonal deformation of the Earth’s crust, and precipitation has an important role in influencing the seasonal deformation of continuous stations.

8

Methodology to improve the accuracy of determining the position of UAVS equipped with single-frequency receivers for the purposes of gathering data on aviation obstacles

Lalak Marta, Krasuski Daniel, Wierzbicki Damian

Zeszyty Naukowe. Transport / Politechnika Śląska

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2023

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z. 119

83--104

EN

Low-altitude photogrammetric studies are often applied in detection of aviation obstacles. The low altitude of the Unmanned Aerial Vehicle (UAV) flight guarantees high spatial resolution (X, Y) of the obtained data. At the same time, due to high temporal resolution, UAVs have become an appropriate tool for gathering data about such obstacles. In order to ensure the required accuracy of orientation of the photogrammetric block, Ground Control Points (GCPs) are measured. The recently introduced UAV positioning solutions that are based on Post-Processing Kinematic (PPK) and Real Time Kinematic (RTK) are known to effectively reduce, or, according to other sources, even completely eliminate the necessity to conduct GCP measurements. However, the RTK method involves multiple limitations that result from the need to ensure continuous communication between the reference station and the rover receiver. The main challenge lies in achieving accurate orientation of the block without the need to conduct time-consuming ground measurements that are connected to signalling and measuring the GCPs. Such solution is required if the SPP code method is applied to designation the position of the UAV. The paper presents a research experiment aimed at improving the accuracy of the determination of the coordinates of UAV for the SPP method, in real time. The algorithm of the SPP method was improved with the use of IGS products.

9

Monitoring of Icelandic plate movement with GNSS method and GPS signal jamming effects in Iceland

Pırtı Atınç, Hoşbaş Ramazan Gürsel, Yücel Mehmet Ali

Reports on Geodesy and Geoinformatics

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2023

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Vol. 116

15--22

EN

Jamming is electromagnetic radiation or reflection that impairs the function of electronic instruments and equipment or communication tools. Intentionally disrupting or interfering with GPS signals, which are used for positioning, navigation, and timing, known as "GPS jamming", is accomplished using a radio frequency emitting device. On January 8, 2022 (the day of a NATO exercise), it was investigated how GPS signal jamming affected the position accuracy at three IGS points in Iceland. The obtained coordinate differences between kinematic processing and static processing reached values of about 0.5-10 meters for the MAYV, and HOFN stations in this study. In addition to GPS signal jamming effect in Iceland, horizontal and vertical velocity fields of the three IGS stations in Iceland covering a twenty-two year period (2000-2022) in this study. According to the obtained results, a motion of about 2cm-2.5cm per year (horizontal) and 0.1cm-2.1cm per year (vertical) was computed at the three IGS stations (HOFN, REYK, and MAYV) located in Iceland.

10

Progression of clock DBD changes over time

Maciuk Kamil, Varna Inese, Kudrys Jacek

Metrology and Measurement Systems

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2023

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Vol. 30, nr 3

499--505

EN

Day-boundary discontinuity (DBD) is an effect present in precise GNSS satellite orbit and clock products originating from the method used for orbit and clock determination. The non-Gaussian measurement noise and data processing in 24 h batches are responsible for DBDs. In the case of the clock product, DBD is a time jump in the boundary epochs of two adjacent batches of processed data and its magnitude might reach a couple of ns. This article presents the four GNSS (Global Navigation Satellite System) systems DBD analysis in terms of change over an 8 year period. For each of 118 satellites available in this period, the yearly value of DBD was subject to analysis including standard deviation and frequency of outliers. Results show that the smallest DBDs appear in the GPS system, the biggest - for the BeiDou space segment. Moreover, the phenomenon of changes in DBDs over time is clearly seen at the beginning of the analysed period when the magnitude and number of the DBDs were larger than for current, newest clock products.

11

Development Of A Monitoring System For Electric Power Substations Based On Ios And Implementation Of Designs On FPGA

Kalimoldayev Maksat, Wójcik Waldemar, Shermantayeva Zhazira

International Journal of Electronics and Telecommunications

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2023

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Vol. 69, No. 4

819--824

EN

In this article, a monitoring system based on IoT technologies of the substation electrical system in the Republic of Kazakhstan was developed. At the moment, the operation of power systems is extremely important to maintain the frequency of electric current over time. For management and monitoring applications, it is necessary to take into account communication within acceptable limits. IoT technologies are considered the main functions in applications for monitoring and managing energy systems in real time, as well as making effective decisions on both technical and financial issues of the system, for monitoring the main form of data registration on an electric power substation in the city of Shymkent of the Republic of Kazakhstan, for consistent effective decision-making by system operators. In this work, an Internet of Things-based monitoring system was implemented and implemented for the substation of the power system using a specialized device built into the FPGA controller for fast integrated digitalization of transformer substations of real-time distribution electrical networks. The IoT platform also provides complete remote observability and will increase reliability for power system operators in real time. This article is mainly aimed at providing a practical application that has been implemented and tested.

12

NFC technology for precise localization in areas with limited global navigation satellite system signal

Szewczyk Robert, Hanus Paweł

Geomatics, Landmanagement and Landscape

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2023

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no. 4

169--180

EN

The emergence of modern technologies and widespread access to the Internet has led to an increase in interest in mapping websites. The data provided by online mapping geoportals is a rich source of information for society. Today, thanks to these geoportals, the location of objects in the field is widely available. This approach makes it possible to locate objects that are not visible in the field, such as underground electrical cables, underground water lines, or property boundaries. The technology used for object localization is GNSS (Global Navigation Satellite System). GNSS technology is based on the transmission of signals from satellites. However, this technology is limited in areas where satellite signals are restricted, such as high-rise buildings in city centers, dense forests, or tunnels. NFC technology is becoming increasingly available thanks to mobile phones that are equipped with NFC tags. This technology is widely used for payments via a mobile phone. This article presents a method of using the near-field communication (NFC) for easy positioning of infrastructure objects in a given area. This technology is particularly useful in areas with limited GNSS signals, such as urbanized, forested, or mountainous areas.

13

Using GPS and Run-Off Rates Data to Study the Close Monitoring Networks for Dams – Al-Kut Barrages as a Case Study

Saiwan Malik Khalaf, Hamdoon Rana Mozahim, Al-Zuhairy Mudhaffar Sadiq

Ecological Engineering & Environmental Technology

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2023

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Vol. 24, iss. 2

87--93

EN

The dams and barrages are among the most important engineering structures for water supply, flood control, agriculture, and electric power generation. Monitoring the horizontal and vertical deformation of the barrage’s body and identifying the risk it’s so important to maintain the dam and also to reduce costs. Where in this research the case of the Al-Kut barrage is studied by observing the body of the barrage using surveying devices through (GPS) by taking spatial observations of the two networks of stations, the horizontal and vertical networks. Then compare them with the observations of previous years to determine the magnitude of the deformation through the differences between the observations. By calculating the differences and finding the displacement of surveying observations from 2014 to 2021, It was found that the highest and least displacements in the horizontal stations is 50 and 11 mm, respectively. Also, for the vertical network observations, the highest and lowest differences in elevation were 11and 3 mm, respectively. Where, the results showed a slight deformation within the acceptable limits. In addition, the annual and monthly discharge rates for a number of years were evaluated to observe the extent of the impact of run-off rates on increasing sedimentation at the upstream of Al-Kut barrage. It was found that the accumulation of sediment on the river’s left bank affected the gates’ efficiency and put pressure on the other gates, which led to some operational issues in the barrage gates.

14

Review on application of location tracking to monitor people in health field against COVID-19

Syamsudin H., Mohammed M. N., Aljibori H. S. S., Al-Tamimi Adnan N. Jameel, Alfiras M., Yusuf Eddy, Abdullah Oday I.

Diagnostyka

|

2023

|

Vol. 24, No. 4

art. no. 2023408

EN

Location tracking stands for technologies that physically identify and electronically register and monitor the tracking of individuals or objects. This technology is widely implemented in the health field for tracking clinicians and patient locations. The history of visited location data is used for many purposes and is mainly applied to monitor and assess the patient’s movement to provide helpful knowledge. This data is obtained using the Global positioning system (GPS), Bluetooth, and Radio-frequency identification (RFID) built into the device such as smartphones, smart watches, or wearable devices. In some Research, other technologies like Google Location History (GLH) provide the history of visited locations made by the Google Account. Location tracking can be an alternative and potentially help monitor and track Covid-19 infectee to prevent wider diffusion. This paper reviews location tracking applications in healthcare based on how the location data is obtained and analyzed. The application of location tracking was differentiated and reviewed based on the applied methods in acquiring knowledgeable data. Furthermore, the data analysis used to track location was also discussed to know what knowledge that obtained from the location history data. Getting the location and assessing the data for specific purposes was also highlighted.

15

Accuracy analysis of aircraft positioning using navigational data from AVIA-W radar

Goś Artur, Krasuski Kamil, Mazur Wojciech

Aviation and Security Issues

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2023

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No. 1

287--312

EN

The paper presents an analysis of the accuracy of determination of parameters of the position of aircraft using data from the AVIA-W radar. In the first place, the authors determined the position of the aircraft as well as the range and azimuth parameters by the AVIA-W radar, located in Dęblin. This was followed by a determination of the absolute position error of the aircraft and the determination of the range and azimuth measurement error by the AVIA-W radar. The research test was carried out using a Diamond DA40 NG aircraft on which a GPS satellite receiver was mounted in order to determine the flight reference position. In addition, the range and azimuth measurements for the aircraft were acquired from the AVIA-W radar. Navigational calculations were conducted for polar and rectangular planar coordinates. Based on the performed research, the azimuth error was found to be -1.4°, while the radar range measurement error was equal to -0.04 km. The conducted research is experimental in its character. In the future it will be repeated and extended to the GCA-2000 radar, which is also located at Dęblin military airfield.

PL

W pracy przedstawiono analizę dokładności wyznaczenia parametrów pozycji statku powietrznego z użyciem danych z radaru AVIA-W. W pierwszej kolejności dokonano wyznaczenia pozycji statku powietrznego oraz określenia parametru zasięgu i azymutu przez radar AVIA-W, zlokalizowany w Dęblinie. Następnie dokonano wyznaczenia błędu absolutnego pozycji statku powietrznego oraz określenia błędu pomiaru zasięgu i azymutu przez radar AVIA-W. Test badawczy przeprowadzono z użyciem samolotu Diamond DA40 NG, na pokładzie którego zamontowano odbiornik satelitarny GPS w celu wyznaczenia pozycji odniesienia lotu. Dodatkowo z radaru AVIA-W pozyskano pomiary zasięgu i azymutu do statku powietrznego. Obliczenia nawigacyjne zrealizowano dla współrzędnych biegunowych i prostokątnych płaskich. Na podstawie wykonanych badań stwierdzono, że błąd azymutu wynosi -1,4°, z kolei błąd pomiaru zasięgu radaru wynosi -0,04 km. Przeprowadzone badania mają charakter eksperymentalny i w przyszłości zostaną powtórzone i rozszerzone o radar GCA-2000, który także znajduje się na lotnisku wojskowym Dęblin.

16

Slip deformation along the Gyaring Co fault from InSAR and GPS

Zhang Qingyun, Li Yongsheng, Zhang Jingfa, Tian Yunfeng, Tian Tian, Li Bingquan

Acta Geophysica

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2023

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Vol. 71, no. 1

53--63

EN

Interferometric synthetic aperture radar (InSAR) can monitor large-scale small deformation. Because the Sentinel-1 satellite has a stable orbit control and the data coherence in Qinghai–Tibet Plateau is good, we utilize data from Sentinel-1 to analyze the slip deformation of the Gyaring Co fault (GCF) in the central Tibetan Plateau. Data are obtained from ascending and descending tracks covering the research area, and the deformation results are obtained by the stacking and analysis of time series. The results demonstrate that the GCF exhibit slow slip overall. An analysis of different sections indicates that the fault displays both right-lateral strike-slip and normal faulting behaviors, and the movement is particularly obvious in the middle section of the GCF. Furthermore, we investigate the contemporary slip rate of the GCF using GPS data and construct two velocity profiles perpendicular to the fault strike at the southeastern and northwestern ends of the fault. The southeastern profile shows ~4 mm/year of right-lateral strike-slip movement and a modest (<1 mm/year) amount of crustal thickening across the fault, while the northwestern profle shows much slower (~ 1 mm/year) right-lateral strike-slip motion and 0.5 mm/ year of crustal extension. The GPS results are consistent with the InSAR deformation map derived using Sentinel-1 A/B data from 2014 to 2017. Our results support the distributed crustal motion model in which most crustal deformation (shortening/ extension/strike-slip) occurs on various active faults in the central Tibetan Plateau rather than being concentrated on several fast-moving fault zones, e.g., the GCF-BCF. Finally, we analyze the distribution of historical earthquakes and the gravity and aeromagnetic felds. We speculate that a fault may exist north of Gyaring Co Lake that may be an extension of the fault north of Mujiu Co Lake.

17

Realizacja układu do pomiaru wpływu poziomu zurbanizowania terenu na jakość wyznaczania pozycji w systemie GPS

Bielawski Antoni, Lazarowska Agnieszka

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

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2022

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Nr 75

9--12

PL

W artykule zaprezentowano projekt układu do rejestrowania położenia bezwzględnego z wykorzystaniem systemu GPS, który umożliwił przeprowadzenie badań nad wpływem poziomu zurbanizowania terenu na jakość wyznaczania pozycji. W tym celu dokonano rejestracji położenia w dwóch miejscach, w terenie zurbanizowanym oraz w dwóch w terenie niezurbanizowanym. Następnie dokonano analizy wyników w oparciu o parametr HDOP (ang. Horizontal Dilution Of Precision – współczynnik geometrycznej dokładności w płaszczyźnie poziomej) oraz liczbę widocznych satelitów.

EN

The article presents the design of the absolute position recording system with the use of the GPS system, which made it possible to conduct research on the influence of the level of urbanization of the area on the quality of determining the position. For this purpose, position registration was made in two places in urbanized areas and in two in non-urbanized areas. Then, the results were analyzed based on the HDOP (Horizontal Dilution of Precision) parameter and the number of visible satellites.

18

Stability of GPS and GLONASS onboard clocks on a monthly basis

Ziętala Michał

Zeszyty Naukowe. Transport / Politechnika Śląska

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2022

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z. 114

193--209

EN

This paper presents the stability of the GPS and GLONASS system clocks’ stability. It describes the construction of these two systems and calculated four different Allan variances (AVAR), based on the MGEX (the Multi-GNSS Experiment) clock products. Four used variances allowed making a better analysis of each GNSS system clock. The results are shown at different averaging times from 5 s as successive multiples to 655,360 s in a monthly period. The stability of GPS and GLONASS clocks is included in the range of 10-12~10-14 s. The results showed that GLONASS clocks are stable (10-12~10-14 s) and are affected with white frequency noise (WFM). The GPS clock stability models have more fluctuations for τ > 40,960 s and the mean stability is concluded between 10-12~10-13 s. Mean frequency accuracy for GPS clocks is related with WFM and Random Walk Frequency (RWF). The differences in clock stability are caused by several factors – block type, type of clock and the time of a satellite in orbit. These factors have an influence on stability results.

19

Accuracy analysis of aircraft positioning using real radar and GPS data

Ciećko Adam, Goś Artur, Krasuski Kamil, Krześniak Kacper

Zeszyty Naukowe. Transport / Politechnika Śląska

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2022

|

z. 116

71--82

EN

This paper presents an analysis of the accuracy of aircraft positioning using radar and GPS satellite data. In particular, this study shows the results of research on determining the position of an aircraft, as well as the range and azimuth parameters for the GCA-2000 radar to the GPS solution. The research used measurement data from the GCA-2000 radar and the Thales MobileMapper Pro receiver placed onboard a Diamond DA-40NG aircraft. The flight experiment was carried out at the EPDE military airport in Dęblin. It was found that the average error in determining the position of the aircraft for the GCA-2000 radar was 295.57 m. Moreover, the average error in determining the range for the GCA-2000 radar is 138.12 m. Additionally, the average error in determining the azimuth for the GCA-2000 radar is equal to 0.408°.

20

Accuracy analysis of aircraft positioning using GPS dual receivers in aerial navigation

Krasuski Kamil, Ciećko Adam, Wierzbicki Damian

Zeszyty Naukowe. Transport / Politechnika Śląska

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2022

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z. 115

23--34

EN

This study presents a modified algorithm to determine the accuracy of GPS positioning in aerial navigation. To achieve this, a mixed model with measurement weights was used to determine the resultant value of accuracy of aerial vehicle positioning. The measurement weights were calculated as a function of the number of GPS tracking satellites. The calculations were performed on actual GPS measurement data recorded by two onboard GNSS receivers installed onboard a Cessna 172 aircraft. The flight test was conducted around the military airport in Dęblin. The conducted analyses demonstrated that the developed algorithm improved the accuracy of GPS positioning from 62 to 91% for horizontal coordinates and between 16-83% for the vertical component of the aerial vehicle position in the BLh ellipsoidal frame. The obtained test results show that the developed method improves the accuracy of aircraft position and could be applied in aerial navigation.