Joongwon Bae

Analysis of GPS Signal Environment for GBAS siting in Gimpo International Airport

Before GBAS ground systems is installed at the airport, the site survey is needed to determine the suitability of proposed GBAS candidate sites depending on the siting requirements. Therefore, analysis of GPS signal reception environment, one of the site survey steps, is required. In this paper, the number of visible satellites, GPS signal strength, multipath error, radio frequency interference and predicted availability were analyzed using the GPS data of Gimpo International Airport measured by PortaSAT equipments and the analysis results were represented.

Development of prototype VDL Mode 2 system in Korea

The Korea Aerospace Research Institute (KARI) has been developing a prototype VDL Mode 2 system since mid of 2005. The purposes of this project are to obtain knowledge, insights and experiences of aeronautical communications trends and technologies and to prepare for future deployment of globally harmonized communication infrastructure consistent with international standards in Korea. The prototype VDL M2 system is composed of ground system and aircraft system. VDL Mode 2 transceiver (VDR), ground station, and simplified CMU and DSP were developed or implemented as a component of the prototype system. In addition, test ATS application including AFN, CPDLC and ADS functions is implemented to verify system operation. The system integration and a series of tests were done by last year and two times flight tests have been performed by April 2009. This paper describes the successful implementation of prototype VDL Mode 2 system in Korea including system architecture and design features. This paper also addresses methodology and progress of the flight test.

GBAS Flight Testing and Performance Assessment using Flight Inspection Aircraft at Gimpo International Airport

Ground Based Augmentation System(GBAS) is a system that offers an aircraft within 23 NM radius from the airport precision positioning service and precision approach service using the concept of Differential Global Positioning System(DGPS). After GBAS ground equipment installing at the airport, functionalities and performances of GBAS should be verified through the GBAS ground and flight testing. This paper describes the methods and results for GBAS flight test using the flight inspection aircraft at Gimpo International Airport. From the test results, we confirmed that the VDB data was received without misleading within the VDB coverage of Gimpo International Airport, and VDB field strength, protection level, and course alignment accuracy met the evaluations criteria.

A Study on a Installation Siting for GBAS Category-I Ground System Implementation in Gimpo Airport

This paper presents site survey processes and the results for installing GBAS Category-I ground system into Gimpo international airport. For siting assessment, many things should be taken into account in advance, such as installation requirement of GBAS components, future airport development plan and possible interference effects to existing facilities. Because overall performance of GBAS system can be affected by GPS signal reception environment, on-site survey should be performed carefully to measure actual GPS environmental performance and determine if any adverse multipath or RFI problems exist or not. In addtion, VDB antenna should be located to ensure line of sight for transmitting VHF signal to deliver GBAS message to aircraft. Based on the survey results, final location for GBAS system installation is selected near runway 32 in the Gimpo airport.

A Study on Siting Criteria for GBAS Ground System

Since the site chosen for GBAS ground system will have a direct effect on the performance of the GBAS, the GBAS ground system siting is mightily important in the GBAS installation process. Therefore, in this paper, the major equipment of the GBAS ground system is introduced and a formal process is described for the identification and evaluation of candidate GBAS sites. Also, this paper described detail siting requirements for the GBAS ground system such as reference receiver, VDB antenna and shelter respectively.