New Methodology for Computing the Aircraft’s Position Based on the PPP Method in GPS and GLONASS Systems

Abstract

In the field of air navigation, there is a constant pursuit for new navigation solutions for precise GNSS (Global Navigation Satellite System) positioning of aircraft. This study aims to present the results of research on the development of a new method for improving the performance of PPP (Precise Point Positioning) positioning in the GPS (Global Positioning System) and GLONASS (Globalnaja Nawigacionnaja Sputnikovaya Sistema) systems for air navigation. The research method is based on a linear combination of individual position solutions from the GPS and GLONASS systems. The paper shows a computational scheme based on the linear combination for geocentric XYZ coordinates of an aircraft. The algorithm of the new research method uses the weighted mean method to determine the resultant aircraft position. The research method was tested on GPS and GLONASS kinematic data from an airborne experiment carried out with a Seneca Piper PA34-200T aircraft at the Mielec airport. A dual-frequency dual-system GPS/GLONASS receiver was placed on-board the plane, which made it possible to record GNSS observations, which were then used to calculate the aircraft’s position in CSRS-PPP software. The calculated XYZ position coordinates from the CSRS-PPP software were then used in the weighted mean model’s developed optimization algorithm. The measurement weights are a function of the number of GPS and GLONASS satellites and the inverse of the mean error square. The obtained coordinates of aircraft from the research model were verified with the RTK-OTF solution. As a result of the research, the presented solution’s accuracy is better by 11–87% for the model with a weighting scheme as a function of the inverse of the mean error square. Moreover, using the XYZ position from the RTKLIB program, the research method’s accuracy increases from 45% to 82% for the model with a weighting scheme as a function of the inverse of the square of mean error. The developed method demonstrates high efficiency for improving the performance of GPS and GLONASS solutions for the PPP measurement technology in air navigation.

Improvement of UAV Positioning Performance Based on EGNOS+SDCM Solution

“…Table 1 describes selected research works in which a weighted average model was used to determine the position of an aircraft. Among the works mentioned [7,[35][36][37], the weighted average model was based on one or two measuring weights. On the other hand, the presented article shows a weighing scheme for three different weighing scales.…”

“…On the other hand, the presented article shows a weighing scheme for three different weighing scales. Moreover, in the works [7,[35][36][37], the experiment used satellite data in the GPS, EGNOS, and GPS/GLONASS systems. On the other hand, the presented work presents a weighted average model for two support systems, SDCM and EGNOS.…”

“…As for the vehicle used in the experiment, it is worth emphasizing that the research tests relate to the aircraft or UAV. Resultant coordinates BLh of UAV [7] Measurement weights were defined as the inverse of the squared mean error values of the determined coordinates [7] Standard deviation of the UAV position calculated from the weighted mean model improved by about 21 ÷ 50% compared to the arithmetic mean model's solution [7] Aircraft [35] Resultant coordinates XYZ of aircraft vehicle [35] The measurement weights are a function of the number of GPS and GLONASS satellites and the inverse of the mean error square [35] The obtained accuracy is better by 11-87% for the model with a weighting scheme as a function of the inverse of the mean error square [35] Aircraft [36] Resultant velocity of aircraft vehicle [36] Measurement weights were defined as the inverse number of GNSS satellites [36] The RMS error of resultant velocity is less than 0.05 m/s [36] Aircraft [37] Resultant coordinates XYZ of aircraft vehicle [37] Measurement weights were used as a function of the number of GPS satellites being tracked, and geometric PDOP (position dilution of precision) coefficient [37] The RMS (root mean square) accuracy of positioning for XYZ geocentric coordinates was better than 1.2% to 33.7% for the weighted average method compared to a single GPS SPP solution [37] In summary, the main achievements at work are:…”

New Methodology of Designation the Precise Aircraft Position Based on the RTK GPS Solution

“…Subsequently, papers [ 32 , 34 , 36 , 37 ] present results of EGNOS (European Geostationary Navigation Overlay Service) solution in relation to the reference position of the flight determined from the differential RTK-OTF technique. Furthermore, in papers [ 38 , 39 ] the results of PPP positioning were compared with the RTK-OTF solution. Then, in the work [ 40 ], the model of the resultant flight speed of the aircraft was calculated and the results were compared with the RTK-OTF precision solution.…”

“…On the basis of the collected publications [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 ], it can be seen that a lot of research work concerned the determination of positioning accuracy using the RTK-OTF technique. In order to better describe the research carried out in the works [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , ...…”