• 한국측량학회지
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• 제29권6호
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• pp.651-657
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• 2011

GPS 관측방정식에서 전리층 지연값과 모호정수는 상관관계가 높기 때문에 충분한 시간동안 취득된 자료가 있어야 모호정수의 결정이 가능하다. 특히, 짧은 시간 동안 취득된 자료를 이용하여 정밀측위를 수행하는 신속정지측위의 경우 모호정수의 결정 여부는 측위정확도에 영향을 주는 핵심 요소라 할 수 있다. 본 연구에서는 전리층 교란이 상대적으로 심했던 2011년 2월 19일 서산, 수원, 원주 상시관측소에서 수신된 GPS 관측자료를 이용하여 신속정지측위를 수행한 후 모호정수가 결정되는 데 필요한 시간을 계산하였다. 총 141개의 세션에 대해 신속정지 측위를 수행하였으며 동일한 시간대에 해당되는 이중차분 전리층 지연 평균값과의 상관관계를 분석함으로써 전리층 교란이 신속정지측위 정확도에 미치는 영향을 분석하였다. 모호정수를 결정하는데 필요한 시간과 이중차분 전리층 지연 평균값과의 상관계수는 0.31로 나타났으며 이로부터 전리층의 교란이 신속정지측위 정확도에 영향을 미치고 있음을 알 수 있다. 따라서 태양폭풍 발생 시 불가피하게 GPS 측량을 수행하는 경우 충분한 시간 동안 취득된 자료를 사용하여야 정밀측위가 가능하다.

• 대한산업공학회지
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• 제25권4호
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• pp.421-436
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• 1999

It is discussed how to locate idle vehicles of AGVS considering dynamically changing situation. Several positioning methods are suggested including static positioning, dynamic positioning with time-independent pickup probabilities, dynamic positioning with time-dependent pickup probabilities, and dynamic positioning with a look-ahead capability. These positioning strategies are compared with each other by a simulation experiment.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.349-352
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• 2005

The telematics positioning testbed is an infrastructure to test and verify positioning technology, the sub-component of telernatics system. The positioning testbed provides the environment of performance analysis for acquisition of static and dynamic positioning information using telematics vehicle. This testbed consists of onboard positioning system, positioning reference station and lab positioning server. The onboard positioning system equipped in telematics vehicle, consists of target positioning system, reference positioning system, and analysis tool. A equipment acquiring high precision positioning data obtained from GPS combined with IMU was set as a reference positioning system. Analysis tool compares observed positioning data with high precision positioning information from a reference positioning system, and processes positioning information. Positioning reference station is RTK system used for reducing atmosphere error, and it transmits corrected information to reference positioning system. Positioning server which is located at laboratory manages positioning database and provides monitoring data to integrated testbed operating system. It is expected that the testbed supports commercialization of telernatics technology and services, integrated testing among component technology and verification.

• Journal of Positioning, Navigation, and Timing
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• 제10권1호
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• pp.67-73
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• 2021

The need for precise location data is growing across numerous markets, and so is the number of affordable high-precision GPS receivers. In this paper, we validated the performance of RTAP2U, a low-cost high-precision RTK receiver that was recently released. Two positioning modes were tested: static and driving. The static test conducted Zero-Baseline Single-RTK and Network-RTK survey for 57 hours and 51 hours, respectively. For the driving test, Network-RTK survey was conducted using VRS services provided by NGII based on Trimble PIVOT and Geo++ GNSMART. The static test showed about 1 cm horizontal and vertical accuracies, which is very stable considering the test duration longer than 50 hours. The integer ambiguity FIX rate marked a solid 100%. The driving test result also reached a 100% FIX rate. Horizontal and vertical accuracies were better than 2 cm and 3 cm, respectively. Researchers can refer to this paper when considering affordable high-precision GPS receivers as an option.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.230-236
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• 2008

In this paper, a model-based stick-slip compensation for the micro-positioning is proposed using an enhanced stick-slip model based on statistical rough surface contact model. The smart structure is comprised with PZT (lead (Pb) zirconia (Zr) Titanate (Ti)) based stack actuator incorporating with the PID (Proportional-Integral-Derivative) control algorithm, mechanical displacement amplifier and positioning devices. For the stick-slip compensation, the elastic-plastic static friction model is used considering the elastic-plastic asperity contact in the rough surfaces statistically. Mathematical model of system for the positioning apparatus was derived from the dynamic behaviors of structural parts. PID feedback control algorithms with the developed stick-slip model as well as feedforward friction compensator are formulated for achieving the accurate positioning performance. Experimental results are provided to show the performances of friction control using the developed positioning apparatus.

• 한국소음진동공학회논문집
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• 제18권11호
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• pp.1134-1142
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• 2008

In this paper, a model-based stick-slip compensation for the micro-positioning is proposed using an enhanced stick-slip model based on statistical rough surface contact model. The smart structure is comprised with PZT(lead (Pb) zirconia(Zr) Titanate(Ti)) based stack actuator incorporating with the PID(proportional-integral-derivative) control algorithm, mechanical displacement amplifier and positioning devices. For the stick-slip compensation, the elastic-plastic static friction model is used considering the elastic-plastic asperity contact in the rough surfaces statistically. Mathematical model of system for the positioning apparatus was derived from the dynamic behaviors of structural parts. PID feedback control algorithms with the developed stick-slip model as well as feedforward friction compensator are formulated for achieving the accurate positioning performance. Experimental results are provided to show the performances of friction control using the developed positioning apparatus.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2583-2605
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• 2016

Fingerprint positioning is a main stream and key technique for seamless positioning systems. In this paper, we develop a performance evaluation testbed for fingerprint based Wireless Local Area Network (WLAN) positioning system. The testbed consists of positioning server, positioning terminal, Access Point (AP) units, positioning accuracy analysis system and testing scenarios. Different from other testbeds tended to focus on testing in same situation, in the proposed testbed, a couple of scenarios are set to test the positioning system including indoor and outdoor environments. Handset-side positioning mode and network-side positioning mode are provided simultaneously. Variety of motion models, such as static model, low-speed model and high-speed model are considered as well as different positioning algorithms. Finally, some implementation cases are analyzed to verify the credibility of the testbed.

• Journal of Positioning, Navigation, and Timing
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• 제5권1호
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• pp.21-28
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• 2016

The Wide Area Differential Global Positioning System (WADGPS) that uses a number of Global Navigation Satellite System (GNSS) reference stations are implemented with various types and provide services as it can service a wide range of areas relatively. This paper discusses a constellation design of reference stations and performance analysis of the WADGPS. It presented performance results of static and dynamic users when wide area correction algorithm was applied using eight reference stations.

• 대한토목학회논문집
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• 제13권2호
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• pp.219-228
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• 1993

지구측위시스템(GPS)은 1980년대 측량분야에서 가장 중요한 기술발전이며 최근에는 수신기의 개선과 데이터 처리기법의 발전에 따라 높은 정확도로서 효율적인 GPS측량이 가능하게 되었다. 이 논문에서는 데이터 선형조합의 방법에 대해 고찰하고 P코드/위상측정용 수신기인 Wild GPS System-200의 테스트 결과를 제시하고 있다. 연구결과는 7km/37km의 기선에서 1ppm 이내의 높은 정확도의 측정이 가능하며 P-코드 수신에 의한 1점측위에서는 10m의 위치정확도가 쉽게 얻어질 수 있으므로 초기좌표 결정에 효과적임을 보여주고 있다.

• 한국음향학회지
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• 제26권4호
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• pp.166-172
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• 2007

본 논문에서는 표적 위치추정기법 및 관측잡음에 따른 다중상태 소나의 표적위치 추정성능에 대하여 논한다. 다중상태 소나망에 대한 기존 정보융합방법인 거리정보만을 이용하는 Maximum Likelihood (ML)와 거리정보와 방위정보를 함께 이용하는 Least Square (LS)에 대한 분석을 기반으로 거리정보와 방위정보를 함께 이용하는 ML을 제안한다. 각 센서가 거리정보와 방위정보를 이용한다고 가정할 때 다양한 잡음 환경하에 기존 방법과 제안된 방법에 대한 비교 실험을 수행했다. 또한 센서 수와 송신기, 수신기간 거리에 따른 표적위치 추정성능에 대한 연구를 수행했다. 실험결과에 의하여 제안된 거리정보와 방위정보를 함께 이용하는 ML의 제곱근 오차 성능이 송수신기간 거리가 길수록, 수신기 수가 적을수록 기존의 거리정보만 이용하는 ML, LS보다 더 우수한 것으로 나타났다.