Relative aircraft positioning based on inertial navigation and datalink

Formation flying has emerged as a prominent aircraft operational mode，necessitating precise relative posi⁃ tioning of aircraft within the formation as a fundamental requirement. In Global Navigation Satellite System（GNSS）-denied environments，aircraft experience a loss of global positioning information，making it challenging to derive rela⁃ tive aircraft positioning solely from local data sources. To address the relative positioning challenge among aircraft within a formation in GNSS-denied environments，this paper introduces a method that integrates data link and inertial navigation. Firstly，the inertial navigation method is employed to give a real-time calculation of the positioning informa⁃ tion of each aircraft，which is then transmitted to other aircraft through its respective data link. Subsequently，each air⁃ craft conducts measurements of the relative positions between the aircraft in the formation by using the received infor⁃ mation from other aircraft and the data link. Finally，leveraging the continuous time series of inertial navigation data and data link measurements，a relative pose optimization factor graph is constructed to solve the relative poses be⁃ tween the aircraft in real time. Simulation and experimental verification are undertaken，employing a two-aircraft forma⁃ tion as a case study. The outcomes indicate that this method proposed enables real-time estimation of the relative po⁃ sitions of aircraft within the formation. Experimental results demonstrate that this method reduces the distance error measured by the data link by 76%，and can provide accurate and reliable relative position information for formation flight. © 2024 Chinese Society of Astronautics. All rights reserved.