Aircraft positioning using GPS/GLONASS code observations Kamil Krasuski, Janusz Cwiklak and Marek Grzegorzewski Institute of Navigation, Polish Air Force University, Dęblin, Poland Abstract Purpose – This paper aims to present the problem of the integration of the global positioning system (GPS)/global navigation satellite system (GLONASS) data for the processing of aircraft position determination. Design/methodology/approach – The aircraft coordinates were obtained based on GPS and GLONASS code observations for the single point positioning (SPP) method. The numerical computations were executed in the aircraft positioning software (APS) package. The mathematical scheme of equation observation of the SPP method was solved using least square estimation in stochastic processing. In the research experiment, the raw global navigation satellite system data from the Topcon HiperPro onboard receiver were applied. Findings – In the paper, the mean errors of an aircraft position from APS were under 3 m. In addition, the accuracy of aircraft positioning was better than 6 m. The integrity term for horizontal protection level and vertical protection level parameters in the flight test was below 16 m. Research limitations/implications – The paper presents only the application of GPS/GLONASS observations in aviation, without satellite data from other navigation systems. Practical implications – The presented research method can be used in an aircraft based augmentation system in Polish aviation. Social implications – The paper is addressed to persons who work in aviation and air transport. Originality/value – The paper presents the SPP method as a satellite technique for the recovery of an aircraft position in an aviation test. Keywords GPS, Accuracy, GLONASS, SPP method, Least square estimation Paper type Research paper Introduction The global navigation satellite system (GNSS) satellite technology is widely used in air, sea and land or car navigation. In particular, in terms of navigation, the GNSS satellite technology is exploited to determine the trajectory of a vehicle movement in a horizontal and vertical plane, to determine the speed of movement of a vehicle, as well as the principal heading, pitch and roll angles in three-dimensional space. However, the key parameter during the navigation using the GNSS satellite technology is to determine the actual trajectory of the vehicle movement. The determination of the actual position of the vehicle using the GNSS satellite technology is important for a number of reasons: safety of navigation in the horizontal and vertical plane, maintaining the continuity of the navigation solution of a vehicle position, determining the basic parameters of the navigation vehicle movement, specifying the reliability of the determined position, informing about a possible collision with other vehicles, continuous tracking the planned route and monitoring changes in a vehicle movement in relation to the adopted route, warning other vehicle users of any problems occurring at certain route sections, verification of the operation of the GNSS system during an operation of a vehicle, examining the state of the constellation of GNSS satellites while the vehicle is in motion, comparison of the indications of a vehicle position from the GNSS sensor with the measurements made by another device installed in the vehicle, error monitoring of thick or sudden variations in the readings of the GNSS sensor, specifying the quality of cooperation with an onboard computer, which manages vehicle movement, etc. The implementation of the GNSS satellite technology in air navigation is particularly important in the age of air transport development in the twenty-first century. In accordance with Annex 10 “Radio Navigational Aids” to the Chicago Convention, the International Civil Aviation Organization (ICAO) introduced certification for using the global positioning system (GPS) global navigation satellite system (GLONASS), aircraft based augmentation system (ABAS), satellite based augmentation system (SBAS) and ground based augmentation system (GBAS) (ICAO, 2006). Among the above-mentioned navigation systems, the GPS and the GLONASS are the most common in practical use in air navigation. The ICAO recommendations for the use of GPS and GLONASS systems in air navigation concern the exploitation of single frequency GPS/ GLONASS onboard receivers as fundamental instrument-board avionics. In addition, it needs to be added that the certification of GPS and GLONASS navigation systems in aviation concerns the precise positioning parameters, i.e. accuracy, integrity, continuity The current issue and full text archive of this journal is available on Emerald Insight at: https://www.emerald.com/insight/1748-8842.htm Aircraft Engineering and Aerospace Technology 92/2 (2020) 163–171 © Emerald Publishing Limited [ISSN 1748-8842] [DOI 10.1108/AEAT-01-2019-0018] The authors would like to thank for CSRS-PPP on-line service for numerical computations. This paper was supported by Polish Air Force University for 2019 year. Received 20 January 2019 Revised 12 May 2019 Accepted 27 September 2019 163