Following the successful demonstrations of GNSS and data link capabilities for precision approaches and landings performed with a SAAB 340 aircraft at Linköping Airport in October 1988 (WingTip, landing demonstrations, October, 1988), the R&D efforts on the aircraft local-area augmentation system that employed DGPS to assist aircraft landing continued. In 1990 the Swedish Civil Aviation Administration (SCAA) entered into a co-operation agreement with GP&C Systems International AB aiming at further exploitation of these technologies. After series of different studies and tests public large scale demonstrations was conducted at Gothenburg-Landvetter International Airport in June 1994. International visitors attended the two-day demonstrations which among others included representatives from the Nordic countries and USA. During the demonstrations precision approaches and landings at a remotely located airport (Såtenäs) using DGNSS data from Gothenburg-Landvetter was shown.
In September and October 1994 around 300 precision approaches and landings were completed at Norrköping- Kungsängen Airport using the so-called GNSS Transponder, Cockpit Display of Traffic Information, one Differential GPS ground station, and a ground monitoring station.
Signals from the GNSS Transponder, which include a GPS receiver and the STDMA data link was integrated with the ILS system and a large number of the test flights were conducted with the so-called Hybrid GNSS-ILS system. The subsequent reports (GNSS Landing Trials at Norrköping-Kungsängen 1994- Arrival Routes, GNSS CAT I, ILS/GNSS Hybrid) was released in December 1994 (three volumes). The reports were later presented to the Special European Regional Air Navigation Meeting, Vienna 5-16 September 1994; (see SP EUR-WP/39, September, 1994) - An intermediate Step in the Transition From ILS to New Approach and Landing Systems) and to the ICAO Special COM/OPS/95 - Meeting in Montreal 27 March 7 April 1995 (See SP COM/OPS/95-WP 32 - An Alternative Architecture that may facilitate the Transition from ILS to GNSS, A Hybrid ILS/GP-GPS Architecture).
A similar hybrid landing concept has also been presented by the Boeing Company (see US Patent 5,786,773, Jul. 28, 1998).
Seach words: GPC Systems International AB, GNSS-Transponder, GNSS Transponder, GP&C Transponder, GPS-Transponder, STDMA data link, SOTDMA, ICAO VDL Mode 2, ICAO VDL Mode 3, ICAO VDL Mode 4, ADS-B broadcast, Surveillance, Mode S Squitter, GPS-Squitter, AMASS, ASDE, TCAS, CDTI, DGPS, DGNSS, GBAS, LAAS, ICAO/AMCP, RTCA Task Force 3, Free Flight Steering Committee, Flight 2000, CNS/ATM, NEAN, NEAP, NAAN, FARAWAY, SUPRA, MAGNET-B, FREER, PETALII, 4S Transponder, AIS transponder, hybrid, landning, ILS, LOC/GS, Håkan Lans, Hakan Lans , http://www.gpc.se, http://www.gpc.se