• 한국전자통신학회논문지
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• 제9권2호
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• pp.195-202
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• 2014

다양한 상업적, 군사적 방면에서 사용되고 있는 위성항법시스템(Global Positioning System: GPS)은 특정 사용자나 물체의 위치를 추정하기 위해 설계되었다. 정확한 위치추정을 위해 위성항법시스템은 최소 네 개의 위성으로부터 신호를 수신하여야 한다. GPS 수신기는 매우 낮은 신호-대-잡음 비(signal-to-noise ratio: SNR)에서 동작하며, GPS 신호에 비해 매우 높은 전력을 가지는 간섭신호들에 의해 위치추정 성능에 영향을 받을 수 있다. 본 논문에서는 고 전력 간섭들을 정확한 GPS 신호의 도래각(angle-of-arrival: AOA) 정보 없이 제거하는 변형된 역확산기(modified despreader) 기반의 다수개의 GPS 신호를 위한 적응 간섭제거기를 소개한다. 또한 변형된 역환산 빔형성기의 출력에 대한 신호-대-간섭 및 잡음 비(signal-to-interference and noise ratio: SINR)의 수학적 해석을 제공한다. 컴퓨터 시뮬레이션을 통해 고려된 GPS 수신기의 간섭제거성능과 SINR에 대한 수학적 해석을 확인한다.

• 한국IT서비스학회지
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• 제9권4호
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• pp.207-217
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• 2010

This paper is concerned with a protection system for the mentally handicapped, which is utilizing a GPS receiver and mobile communications. The protection system consists of a location notification equipment, a location identification and management server, and a cell phone of guardian. The location notification equipment is made up of a GPS receiver, a CDMA communication module and a microprocessor. The equipment transfers the location of the mentally impaired to the location identification and management server when the handicapped gets out of a certain bound of the designated facility. The server marks the handicapped's location on the map in the server and also notifies the guardian's cell phone of the locations. With applying the proposed protection system to social welfare organizations related to the mentally handicapped, it is expected to efficiently contribute to the promotion of the handicapped's welfare.

• 한국통신학회논문지
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• 제22권3호
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• pp.506-514
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• 1997

In this paper, we implement digital circuit of despreading delay lock loop for GPS receiver. The designed system consists of Epoch signal generator, two 13bit correlators which correlates the received C/A code and the locally generated C/A code in the receiver, the C/A code generator which generates C/A code of selected satellite, and the direct digital clock synthesizer which generates the clock of the C/A code generator to control the phase and clock rate, the clock controller, and the clock divider. The designed circuit has the function of the acquisition and tracking by the autocorrelation characteristics of Gold code. The controller generates each other control signals according to the correlation value. The designed circuit is simulated to verify the logic functional performance. By using the simulator STR-2770 that generates the virtual GPS signal, the deigned FPGA chip is verified the circuit performance.

• Journal of Positioning, Navigation, and Timing
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• 제7권4호
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• pp.227-233
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• 2018

The purpose of satellite navigation meaconing jamming is to make the target GPS receiver calculate false navigation by meaconing the received satellite signals. At this time, since the received and transmitted signals have the same frequency, the back-lobe reduction level of antenna should be -160 dB when the Effective Radiated Power (ERP) is 1 Watt (30 dBm). Therefore, meaconing jamming is impossible by merely reducing the back-lobe level of antenna when the transmitter and receiver are in proximity to each other. In general, the transmitter and receiver are isolated by the time division method to eliminate such transmission/reception interference. This paper studied the optimal switching timing between transmitting and receiving when isolating the time division transmission and reception for GPS meaconing jamming.

• 센서학회지
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• 제18권1호
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• pp.22-27
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• 2009

The GPS(global positioning system) made up of 28 artificial satellites going round around the earth at a height of 20,000.Km is a system to determine the receiver's location by measuring the distance between the satellite and receivers using an electronic wave. Recently it's been widely used in various applications, such as a navigator, a surveying system, etc. In this paper, we propose a new algorithm to transform coordinates from GPS signals corresponding to various sizes of maps, and the application using this algorithm is also introduced. The algorithm is programmed by MFC on the WinCE 5.0 operating system, and the GPS receiver with a 20 channel high sensitivity and GPS microcontroller chip manufactured by SiRF Technology was used.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1998년도 제 23회 정기총회 및 추계학술발표회
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• pp.65-73
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• 1998

Ship's positino data obtaining method is ine of the very important factor innavigation . Nowadays, GPS(Global Positioning System) using the earth orbiting satellites are equipped and operated for the position finding. Because it provides more precise position information than other equipments and is very convenient for navigator. In this study, it is designed to develop the GPS simulator for everybody being able to proactise the GPS operating skill like as navigation planning, navigation calculating etc. And also, it can be operated with personal computer without real GPS receiver. This simulation system is based on the real GPS receiver system and built by the visual basic 5.0 program. And it displays the ship's position and navigating information and plots the ship's moving track on the screen in real time according as initial setup data-main engine's rpm, rudder angle, depature position and waypoint.

• 한국항공우주학회지
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• 제38권8호
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• pp.781-789
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• 2010

GPS/INS 통합시스템의 고장검출에는 카이제곱 분포 기반의 알고리즘이 일반적으로 사용된다. 본 논문에서는 기존의 RAIM (Receiver Autonomous Integrity Monitor)과 카이제곱 분포 기반의 알고리즘을 결합하여 무인기용 저급 프로세서에 적용하기 위해 단순화시킨 GPS/INS 고장검출 알고리즘을 제안한다. 제안한 알고리즘의 검증을 위해 고장모델을 사용하여 그 결과를 나타내었다.

• 해양환경안전학회지
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• 제21권3호
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• pp.234-239
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• 2015

This paper focuses on analyzing the modern warfare and weapon systems supported by improved GPS informations. The GPS capability was investigated through the real experimental test for verifying the most recent GPS features under its modernization processing. And then it was verified that such capabilities, accuracy and availability, of a typical L1, C/A code GPS receiver are equivalent to the military receiver's ones. It was also sure that the influence of GPS improved informations on NCW(Network-Centric Warfare), PGM(Precision Guided Munition) and C4SIR(Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance) should be increased and the modern warfare may be strongly dependent on GNSS informations.

• 한국군사과학기술학회지
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• 제6권1호
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• pp.49-58
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• 2003

Compared with generic GPS receiver, post-processing software GPS receiver has many advantages for high dynamic vehicle tracking. It has the advantage of the application of various tracking algorithms and aiding schemes. The post-processing system observes the carrier phase measurement data from the recorded GPS signals, detects and isolates the cycle slip. The observed carrier phase data and the raw data of the reference station are processed by carrier phase DGPS scheme. And the integer ambiguity resolution algorithm is used for resolving single frequency carrier phase ambiguity. The results of static and real flight test are presented and show that the proposed GPS translator processing system satisfies submeter accuracy.

• 한국항해학회지
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• 제24권4호
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• pp.219-226
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• 2000

Ship's position data obtaining method is one of the very important factor in navigation. Nowadays, GPS(Global Positioning System) using the earth orbiting satellites are equipped and operated for the position finding. Because it provides more precise position information than other equipments and is very convenient for navigator. In this study, it is designed to develop the GPS simulator for everybody being able to practise the GPS operating skill like as navigation planning, navigation calculating etc. And also, it can be operated with personal computer without real GPS receiver. This simulation system is based on the real GPS receiver and built by the visual basic 5.0 program. And it displays the ship's position and navigating information and plots the ship's moving track on the screen in real time according as initial setup data-main engine's rpm, rudder angle, departure position and waypoint.