• Aerospace Engineering and Technology
• /
• v.5 no.2
• /
• pp.16-26
• /
• 2006

GNSS is a satellite-based radio navigation aid. For using it in civil air navigation area, any GNSS service should meet the requirements of accuracy, integrity, continuity and availability in each flight phase established by ICAO. In this study, a remote integrity monitoring system(RIMS) for GNSS are proposed and explained to utilize it in the design of GNSS augmentation system such as GBAS and GRAS. The RIMS consists of signal-in-space receiving subsystem and signal processing subsystem. Each GPS receiver is connected to Host PC by the serial to ethernet converting device which is able to convert serial port connection to LAN port connection in order to exchange information via the internet. We can overcome the siting limitation of GPS receiver and antenna, and reduce signal loses in the cable between GPS antenna and receiver. This system is providing the development environment for GBAS CAT-I system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.6 no.8
• /
• pp.1175-1180
• /
• 2002

In this paper, we implemented the sign board that is able to display the located based information by adding the GPS module to the board that display the DARC information and user`s message. The global positioning information from GPS module gets more correct by DGPS from DARC module. This information help this system select the located based information for broadcasting. From the experiment, we confirmed that this system displayed user`s data, DARC information data and located based information.

• KIISE Transactions on Computing Practices
• /
• v.21 no.12
• /
• pp.798-803
• /
• 2015

DGPS is a technology that can improve the positioning precision of the existing GPS based on the correction information regarding reference station. Although the country is currently building infrastructure for DGPS correction information to be transmitted, it is being used only in limited areas for which DGPS expensive equipment is required. By enabling the development of the DGPS device using the smart phone, this limitation can be overcome, DGPS can be applied for various location-based services, and the implementation of the new model of location-based services may be enabled. In this paper, we introduce the development of a DGPS device for which high-precision positioning is possible using DGPS correction information received via the DMB network or mobile network in the smart phone environment.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2012.06a
• /
• pp.71-73
• /
• 2012

하드웨어 방식의 DGPS 기준국 시스템을 개선한 차세대 DGPS 기준국 아키텍처인 소프트웨어 DGPS 기준국 시스템은 하드웨어 방식에서 발견된 많은 문제점을 개선한다. 그러나, 초기의 소프트웨어 DGPS 기준국 시스템은 차세대 아키텍처를 충실히 따르고 있기는 하지만 소프트웨어의 구조에 단점을 내포하고 있어 실제 적용에 어려움이 있다. 본 논문에서는 기존 소프트웨어 DGPS 기준국 시스템의 단점을 보완하고 구조를 개선한 새로운 아키텍처를 설계하고 이 아키텍처를 기반으로 한 실제 소프트웨어를 구현한다.

• Journal of Navigation and Port Research
• /
• v.37 no.1
• /
• pp.49-54
• /
• 2013

This paper describes the progress and results of 'Wide Area Differetial GNSS (WA-DGNSS) Development' project which is supported by Korea Ministry of Land, Transport and Maritime Affairs. This project develops the main algorithm of the WA-DGNSS which can guarantee the improved accuracy, availability and integrity all over the Korean peninsula. After the establishment of WA-DGNSS ground system, a real time demonstration using pseudolite will be conducted. Product of this project will be directly utilized in Korean Satellite Based Augmentation System(SBAS) development project which is planned to be started from 2014.

• Journal of Advanced Navigation Technology
• /
• v.25 no.3
• /
• pp.194-202
• /
• 2021

Ionosphere, one of the largest error sources, can pose potentially harmful threat to single-frequency GNSS (global navigation satellite system) user even after applying ionospheric corrections to their GNSS measurements. To quantitatively assess ionospheric impacts on the satellite navigation-based applications using simulation, the standard deviation of residual ionospheric errors is needed. Thus, in this paper, we determine conservative statistical quantity that covers typical residual ionospheric errors for nominal days. Extensive data-processing computes TEC (total electron content) estimates from GNSS measurements collected from the Korean reference station networks. We use Klobuchar model as a correction to calculate residual ionospheric errors from TEC (total electron content) estimate. Finally, an exponential delay model for residual ionospheric errors is presented as a function of local time and satellite elevation angle.

• Journal of Advanced Navigation Technology
• /
• v.11 no.1
• /
• pp.1-8
• /
• 2007

Loran-C of ground transmitting station base that can prevent confusion of country navigation system and give BACK-UP function about electric wave navigation comparing utilization incapability state about GPS(Global Positioning System) infra that user is spreading rapidly over our society whole such as sea/aviation safety, vehicles navigation, minuteness agriculture, minuteness measurement in this treatise practical use of Loran-C navigation propose. Executed ASF(Additional Secondary Phase Factor) production and an application experiment Loran-C by location error improvement way to enhance practical use value. By the result Loran-C in conclusion that can improve location error 100~400m remarkably by 10~65m reach. Also, production extent is latitude when go composition medium and bends cotton at ASF revision table utilization of land area, this smell is judged to be suitable hardness 10 minutes. And notable location error improvement and numeric of GPS BACK-UP function are judged to be possible at a ASF revision table application to Korea Peninsula whole area hereafter.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2016.05a
• /
• pp.685-688
• /
• 2016

SBAS(Satellite Based Augmentation System) broadcasts the correction message based on satellite communication to improve the positioning accuracy of GNSS user. For this reason, SBAS is actively being utilized on navigation part. To apply SBAS to navigation part, it should satisfy not only accuracy but also integrity, continuity, availability, coverage requirements and so on. Since SBAS reference station is the base infrastructure of SBAS, it is the main factor to determine the environment, position, and geometry of reference stations to achieve SBAS service performance. Therefore, a site environmental analysis should be performed prior to the selection of SBAS reference station. In this paper, it performs the environmental analysis of NDGPS(Nationwide Differential GPS) reference station sites on the premise that SBAS reference station will be co-operated in the same site of NDGPS operated by MOF(Ministry of Oceans and Fisheries). The environmental analysis is conducted as carrying out the visibility analysis of GPS satellite and interference analysis. This paper also presents the brief procedures and requirements for site survey of SBAS reference station.

• Journal of Positioning, Navigation, and Timing
• /
• v.13 no.4
• /
• pp.505-514
• /
• 2024

The aim of this study is to evaluate the performance of navigation during take-off and landing by conducting Satellite-Based Augmentation System (SBAS) flight tests equipped with various SBAS enabled GNSS receivers on the Korea Urban Air Mobility (K-UAM) demonstration routes to measure the positional accuracy and to assess the Real-Time Kinematic (RTK) positional accuracy near Vertiports. The flight tests were conducted by repeatedly traveling along the Ara Waterway route between Gaeyang vertiport and the Drone Certification Center of KIAST, designated as the GC 2-1 demonstration route. During the flight tests, SBAS navigation positions and raw observational data were recorded, while RTK positions and raw observational data were recorded near vertiports. Using the stored data, dynamic reference position data were generated through post-processed RTK, and the positional accuracy of SBAS on the demonstration route and RTK near vertiports were evaluated. The results indicated that the SBAS performance on the route ranged between 1.5 to 2.6 meters, while RTK demonstrated highly precise accuracy of under 10 cm. This study provides essential foundational data for evaluating the performance of navigation systems related to K-UAM initial commercialization. By statistically calculating and analyzing the Navigation System Errors (NSE) within corridors and at vertiports, this study is expected to contribute to establishing Total System Error (TSE) evaluation criteria. Additionally, it is anticipated to play a significant role in future GC Phase 2 demonstration trials and technical development.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.23 no.6
• /
• pp.505-510
• /
• 2013

In order to detect and identify the GPS clock anomaly in the Differential GPS real environment, this paper addresses a method for minimizing the measurement noise of reference receivers. It estimates the real measurement noise that removed the uncommon error source from pseudorange measurement to minimize the measurement noise. Based on the output of two reference receivers, it first removes the uncommon errors, then optimizes the measurement noise by applying the correction data. Finally, it detects and identifies the satellite clock anomaly using the minimized measurement noise. The method will increase the availability of current DGPS reference system.