Adam Ciećko

Official ICAO certification for the Galileo satellite navigation system is currently being implemented for aeronautical applications. Hence, experimental studies are needed to verify the performance of Galileo for kinematic positioning of the user in aviation. The main objective of this work is to present an optimal computational strategy for determining the user's position and the accuracy parameter of Galileo positioning in civil aviation. The paper uses the least squares method and Kalman filtering to calculate the user position. The calculations were performed in two independent Galileo observation processing software, i.e., RTKLIB and Emlid Studio. Galileo navigation and observation data acquired from a DJI Matrice RTK300 unmanned platform was used in the calculations. The Galileo SPP code method algorithm was used to determine the UAV coordinates. The RTKLIB application uses a solution based on the least squares method model to determine user coordinates using the SPP method. The Emlid Studio application, respectively, is based on the Kalman filtering algorithm. On this basis, the UAV positions were determined for the two computational strategies, and the Galileo positioning accuracy was then determined in the form of position errors and RMS errors. The study shows that Emlid Studio software improves Galileo's kinematic positioning accuracy by between 15 and 65% over the results obtained from the RTKLIB solution. The flight tests carried out, the software used, and the computational strategies can be utilized for other global GNSS systems.

This paper presents a modified algorithm for determining the positioning accuracy of a UAV based on a joint GPS/EGNOS+GPS/SDCM (Global Positioning System/European Geostationary Navigation Overlay Service+Global Positioning System/ System for Differential Corrections and Monitoring) solution....

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 determine 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 algorithm 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 (Global Positioning 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.

The potential for the use of smartphones in GNSSs (Global Navigation Satellite Systems) positioning has increased in recent years due to the emergence of the ability of Android-based devices used to process raw satellite data. This paper presents the results of a study on the use of SBAS data transmitted by the EGNOS (European Geostationary Navigation Overlay Service) system in GNSS positioning using a Xiaomi Mi8 smartphone. Raw data recorded at a fixed point were used in post-processing calculations in GPS/EGNOS positioning by determining the coordinates for every second of a session of about 5 h and comparing the results to those obtained with a Septentrio AsteRx2 GNSS receiver operating at the same time at a distance of about 3 m. The calculations were performed using the assumptions of the GNSS/SBAS positioning algorithms, which were modified with carrier-phase smoothed code observations and the content of the corrections transmitted by EGNOS.

This paper presents an algorithm for determining the precision parameter for aircraft position coordinates based on a combined GPS/EGNOS and GPS/SDCM solution. The proposed algorithm uses a weighted average model that com-bines a single GPS/EGNOS and GPS/SDCM position navigation solution to determine the resulting aircraft coordi-nates. The weighted mean model include the linear coefficients as a function of: the inverse of the number of tracked GPS satellites for which EGNOS and SDCM corrections have been generated, and the inverse of the geometric coeffi-cient of the PDOP (Position Dilution of Precision). The corrections between the single GPS/EGNOS and GPS/SDCM solution to the aircraft's resultant coordinates are then calculated on this basis. Finally, the standard deviation for the aircraft resultant BLh (B-Latitude, L-Longitude, h- ellipsoidal height) coordinates is calculated as a measure of preci-sion. The research experiment used recorded on-board GPS+SBAS data from two GNSS receivers mounted on a Dia-mond DA 20-C1 aircraft. The test flight was carried out on the Olsztyn-Suwaki-Olsztyn route. The calculations of aircraft position based on GPS/EGNOS and GPS/SDCM solution were performed in the RTKLIB v.2.4.3 program in the RTKPOST module. Next, aircraft resultant coordinates and standard deviations were computed in Scilab v.6.0.0 soft-ware package. Based on the tests performed, it was found that for the Trimble Alloy receiver, the standard deviation values for the ellipsoidal coordinates BLh of the aircraft do not exceed 1.77 m. However, for the Septentrio AsterRx2i receiver, the values of standard deviations for the aircraft's ellipsoidal BLh coordinates do not exceed 5.04 m. The use of linear coefficients as the inverse of the number of tracked GPS satellites with SBAS corrections in the GPS/EGNOS+GPS/SDCM positioning model resulted in a reduction in standard deviations of approximately 50-51% relative to the solution with linear coefficients calculated as the inverse of the PDOP parameter. In paper, the standard deviation was also obtained using arithmetic mean model. However the values of standard deviation from weighted mean model are lower than arithmetic mean model.

The aim of this article was to investigate the accuracy of determining the position parameters of an aircraft by the GCA 2000 airport control radar located at Deblin Airport (EPDE). In order to analyse the accuracy of determining the position of an aircraft by the GCA 2000 radar, a research flight was carried out. The position of the aircraft was recorded by the GCA 2000 radar and the Thales Mobile Mapper Pro GPS receiver on board the aircraft. The resulting position parameters were compared with each other to investigate the accuracy of the radar’s coordinate determination. In addition, a number of analyses and comparisons were performed to determine the reasons for the interruptions in the radar detection of the aircraft. Based on the study, it can be concluded that the GCA 2000 radar located at Deblin airport meets the requirements set by the International Civil Aviation Organisation (ICAO) for radar performance. According to ICAO, the standard deviation of the distance error should be 70–130 metres and the azimuth error for primary radars should be 0.15–0.2°, and for secondary radars 0.2–0.3°. The standard deviation of the distance error during a research flight by the GCA 2000 radar is 81.1 metres and the standard deviation of the azimuth error is 0.19°.

The purpose of this publication is to determine the accuracy of EGNOS positioning in aviation using correction data from the PRN120 and PRN124 geostationary satellites. The paper compiles GPS satellite data with EGNOS corrections to determine the position of aircraft and to determine positioning accuracy. The study used research material from an airborne experiment carried out in Mielec. GNSS data were elaborated in post-processing mode in the RKTLIB software, and numerical analyses were performed in Microsoft Excel. The average accuracy of EGNOS positioning using data from the PRN120 satellite for B, L, h coordinates was 0.9 m, 0.2 m and 0.3 m, respectively. In contrast, the average accuracy of EGNOS positioning using data from the PRN124 satellite is also similarly 0.9 m, 0.2 m and 0.3 m for BLh coordinates. It was observed that the positioning accuracy at a given measurement epoch is dependent on the number of GPS satellites observed. Furthermore, in the study, the accuracy of EGNOS positioning using corrections from the PRN120 and PRN124 satellites was compared with the certification requirements of the International Civil Aviation Organisation.

The article presents the results of research on the development of a method for improving the positioning accuracy of an UAV equipped with a single-frequency GPS receiver for determining the linear elements of exterior orientation in aerial photogrammetry. Thus, the paper presents a computational strategy for improving UAV position determination using the SPP code method and the products of the IGS service. The developed algorithms were tested in two independent research experiments performed with the UAV platform on which an AsteRx-m2 UAS single-frequency receiver was installed. As a result of the experiments, it was shown that the use of IGS products in the SPP code method made it possible to improve the accuracy of the linear elements to the level of about ±2.088 m for X coordinate, ±1.547 m for Y coordinate, ±3.712 m for Z coordinate. The paper also shows the trend of changes in the obtained accuracy in determining linear elements of exterior orientation in the form of a linear regression function. Finally, the paper also applies the SBAS corrections model for the improvement of UAV position calculation and determination of linear elements of exterior orientation. In this case, the improvement in the accuracy of determining the linear elements of exterior orientation is about ±1.843 m for X coordinate, ±1.658 m for Y coordinate, ±7.930 m for Z coordinate. As the obtained test results show, the use of IGS products and SBAS corrections in the SPP code method makes it possible to improve the determination of UAV positions for the use in aerial photogrammetry.

Unmanned aerial vehicles (UAVs) have become very popular tools for geoinformation acquisition in recent years. They have also been applied in many other areas of life. Their navigation is highly dependent on global navigation satellite systems (GNSS). The European Geostationary Navigation Overlay Service (EGNOS) is intended to support GNSSs during positioning, mainly for aeronautical applications. The research presented in this paper concerns the analysis of the positioning quality of a modified GPS/EGNOS algorithm. The calculations focus on the source of ionospheric delay data as well as on the aspect of smoothing code observations with phase measurements. The modifications to the algorithm concerned the application of different ionospheric models for position calculation. Consideration was given to the EGNOS ionospheric model, the Klobuchar model applied to the GPS system, the Klobuchar model applied to the BeiDou system, and the NeQuick model applied to the Galileo system. The effect of removing ionospherical corrections from GPS/EGNOS positioning on the results of the determination of positioning quality was also analysed. The results showed that the original EGNOS ionospheric model maintains the best accuracy results and a better correlation between horizontal and vertical results than the other models examined. The additional use of phase-smoothing of code observations resulted in maximum horizontal errors of approximately 1.3 m and vertical errors of approximately 2.2 m. It should be noted that the results obtained have local characteristics related to the area of north-eastern Poland.