Global Navigation Satellite Systems Applications in Modern Aviation and Terrestrial Applications

摘要

Global navigation satellite systems (GNSS) have become present in virtually all areas of social, commercial and private life. This technology became an essential component for modern navigation on land, water and air. Its use extended also to map making and land surveying and today's uses of it go further beyond the preliminary applications. Currently, we can talk about multiconstellation GNSS. It is composed not only of American GPS, but also of additional constellations used for corrections of the signal, such as for example: Wide Area Augmentation System (WAAS) in the USA, or European Geostationary Navigation Overlay Service (EGNBOS) in Europe. It is also well known that European Union decided to launch its own GNSS program called Galileo, however it is still far from operational phase. Recently, Russia implemented its own GNSS called GLONASS and China develops system called BeiDou (Chinese name of the Big Dipper constellation used for navigation, and hence, having metaphoric meaning: Compass). The plenary lecture presents applications of contemporary multiconstellation GNSS in aviation and terrestrial applications based research performed within the EGALITE project (www.egalite-project.eu) funded by European Union, whose foundations arose from EDCN (EGNOS Data Collection Network) and the ability offered by innovative Virtual Flying Laboratory (VFL) at Silesian University of Technology. The project started with enhancements of a software package for gathering in MS SQL database the high-throughput satellite navigation data, which is integrated with 3D visualization module GPS3D Viewer. The software package is also integrated with PEGASUS, a program authorized by EUROCONTROL organization. The database and the GPS3D Viewer are designed and functionally extended using the most recent software development technologies for continuous storing, administrating and postprocessing of the EGNOS signal data. Their operation within distributed, Pan-European EDCN system has already made possible detection of important but rare events, such as sudden accuracy degradation, subject for further identification by EUROCONTROL, an organization responsible for the safe use of satellite navigation in European civil aviation. Additionally to single constellation signal, the more accurate localization can be achieved in Ground Based Augmenting System (GBAS) or Satellite Based Augmenting System (SBAS). The example of the first is the European Positioning (EUPOS) network delivering correction signals by radio, the example of the second is WAAS in the USA or EGNOS, a common project of European Union, European Space Agency (ESA) and European Organization for the Safety of Air Navigation (EUROCONTROL). In the interdisciplinary EGALITE project, the innovative technologies originated from ICT are studied, varying from the on-ground precise positioning using GNSS and other sensors (for example in inertial navigation) as well as application of GNSS to vertical guidance in aviation in order to increase safety of the close-to-ground operations of helicopters. In such approach, it is necessary to consider the interplay of many qualitatively different factors, which act simultaneously and cause significant errors in positioning. The group of external factors such as architecture of GNSS systems in multiconstellation approach, influences the positioning accuracy by laws of physics, dynamics ionosphere and troposphere, and electromagnetic phenomena. The corrections of time scales caused by relativistic effects resulting both from Einstein's special and general (gravitational) theories of relativity have to be considered as well in any GNSS constellation. Additionally, internal factors, such as construction of the receivers, their ability of making use of augmentation signals, and computational algorithms applied are important for the final result of position measuring. Although mathematical models for positioning are generally known, the implementation of innovative computational algorithms can increase the accuracy in accordance with EUROCONTROL recommendations for the SBAS/EGNOS augmentation and the ionospheric range correction RCL1/L2. As mentioned above, the performed research is using the capabilities of the Virtual Flying Laboratory (VFL) at SUT. It is an exceptional interdisciplinary laboratory, where cutting-edge technologies from aviation are combined with the newest trends in ICT, in particular, virtual reality and visualization, and with satellite navigation systems GNSS. VFL is co-financed by European Union from the European Regional Development Fund within the Project considered as a winner among more than 100 others in Silesia, the most industrial region in Poland. It is equipped with 14 professional flight simulators, including full-size cockpit simulators: two cockpit simulators: ELITE Evolution S812 and ELITE Evolution S923 equipped with 3-channel visualization technology, are compliant with JAR-STD 3A (Evolution S923 is additionally capable for MCC); two others, manufactured by FLYIT (FAA approved: PHS for helicopter and PAS for aircraft), are installed in mobile class-room platforms with heating and air-condition. Due to mobility, it is possible to move them to distant places where research and/or demonstration field experiments are planned. The instrumentation includes a full IFR panel with all engine and fuel gauges, engine/rotor RPM, AH, ALT, ROC, T&B, HSI, VOR, ADF, and Transponder. Engine gauges can be selected as reciprocating or turbine. The software includes Jeppesen 20,000 airport database, with associated Navaids, and the entire earth surface with accurate elevation/obstructions. Software for PHS provides an accurate flight model including translation lift, ground effect, torque, auto-rotation for selectable 6 helicopter models: Piston R-22, R-44 (VFR-IFR), Schweizer 300 (VFR-IFR), Enstrom 280FX, Turbine-MD 500, Bell 206 (IFR). In stationary simulators such airplanes as Cessna 172RG, Piper Seneca III, Piper Arrow IV and King Air B200 are available. For all cockpit simulators, professional instructor command centres are supplied. Through command center, the operator can select any meteorological weather condition including precipitation, change clouds and wind direction and intensity at multiple elevations, record and replay flights, move a map, make a flight review, or print a flight path. Additionally, the professional GARMIN GNS430 original GNSS simulation devices are installed in stationary cockpit simulators, which, due to vertical navigation function, make possible to define various approaches, manoeuvres, and procedures based on GNSS. Particular problem of integration of flight simulator installed in VFL with the GNSS-based guidance system is described in more detail in a regular paper written by my collegues and me: O. Antemijczuk, D. Sokolowska, K.A. Cyran, "Integration of the MS ESP flight simulator with GNSS-based guidance system", and presented at this conference separately.