• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.151-156
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• 2015

As the proliferation of smart phone, almost every user has one's own smart phone, and the user could get the global position and location based services using GPS system outdoors. But indoor positioning system using GPS does not work, and it could not detect global position using TDOA local positioning system. In this paper, a new indoor global positioning system for smart phone employing GPS receiver and electronic compass device is proposed with the TDOA local positioning system using acoustic signal, and the performance and the experimental result are described.

• Journal of Applied Reliability
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• v.8 no.3
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• pp.125-134
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• 2008

Global Positioning System(GPS) is prospects item of information infrastructure with internet. Global Positioning System module made by domestic have high technology, but its international competitive power is very weak because of reliability. In this paper, we compare domestic products with foreign advanced products exactly, and confirm excellence of domestic products.

• Journal of Navigation and Port Research
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• v.26 no.3
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• pp.303-310
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• 2002

Nowadays, the combined land navigation system using GPS(Global Positioning System) and DR(Deduced Reckoning), etc. has been used. Although GPS is popular with the land navigation system, this is not useful for the kinematic positioning of the vehicles in the urban canyon because of its few satellites. Thus, this study deals with the kinematic positioning of the vehicles with the combined GPS/GLONASS(GLObal Navigation Satellite System) to compliment the drawbacks of GPS. So the kinematic positioning of the vehicles can be performed constantly by the combined GPS/GLONASS based on the high acquisition rate of data with the help of GLONASS despite of many obstacles and few satellites tracked in the test sites. Consequently, the combined GPS/GLONASS can be applicable to the control of traffic flow and the effective management of read system.

• Journal of Korean Society for Geospatial Information Science
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• v.15 no.4
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• pp.41-50
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• 2007

This study aims to suggest efficient setting up of GPS (Global Positioning System) for cadastral surveying. In order to perform it effectively, worldly used modern surveying technology GPS introduced. In a practical analysis, GPS observation had been performed in the research area and the results had been compared and analysed with the results of Total Station. As a results, it is shown that GPS is more efficient rather than current surveying method in terms of time, cost and economy. The results of GPS surveying were included in the scope of error tolerance, being accepted by cadastral laws, showing high accuracy of GPS surveying method. With the results of analysis, how to application of GPS for cadastral surveying was suggested.

• Journal of Positioning, Navigation, and Timing
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• v.3 no.1
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• pp.31-36
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• 2014

Precise Point Positioning (PPP) is a stand-alone precise positioning approach. As the quality of satellite orbit and clock products from analysis centers has been improved, PPP can provide more precise positioning accuracy and reliability. A combined use of Global Positioning System (GPS) and Global Orbiting Navigation Satellite System (GLONASS) in PPP is now available. In this paper, we explained about an approach for combined GPS and GLONASS PPP measurement processing, and validated the performance through the comparison with GPS-only PPP results. We also used the measurement obtained from the GRAS reference station for the performance validation. As a result, we found that the combined GPS/GLONASS PPP can yield a more precise positioning than the GPS-only PPP.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.1
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• pp.27-33
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• 2011

In this paper, for a software-based Global Positioning System receiver (SGR), the principle capturing Global Positioning System (GPS) signal is researched extensively in order to analyze the processing of the GPS raw data signal at the lowest level, and the process of capturing the GPS signal was simulated by Matlab. The simulation results show the accuracy and the feasibility of this method, which is comparable to study under a true environment. We know that the improvement of the receiving facilities is of very vital significance to the performance of this system, and the fine frequency can be found through comparing phases within a few tens of Hertz.

• Journal of Satellite, Information and Communications
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• v.8 no.2
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• pp.62-67
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• 2013

Recently, users have been receiving LBS(Local Based Service) which provides various services. The LBS uses positioning information from satellites with using GPS(Global Positioning System). However, due to satellite signal's characteristics which are reflection and refraction in urban areas, users get unexpected positioning information error, expecially if there are so many tall buildings in a small area. To solve this problem, this paper offers a post-processing algorithm. It is consisted of users' direction vectors and positioning information. The positioning information with error is designed to be put on the direction vector. Through a car driving test in urban areas, we've got 11.1m(43%) improved result and demonstrated the superiority of its algorithm.

• Journal of Positioning, Navigation, and Timing
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• v.5 no.4
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• pp.165-172
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• 2016

A Global Navigation Satellite System (GNSS), which is typically exemplified by the Global Positioning System (GPS), employs a open signal structure so it is vulnerable to spoofing electronic attack using a similar malicious signal with that used in the GPS. It is necessary to require a spoofing test evaluation environment to check the risk of spoofing attack and evaluate the performance of a newly developed anti-spoofing technique against spoofing attacks. The present paper proposed a simulation method of spoofing environment based on simulator that can be implementable in a test room and analyzed the spoofing simulation performance using commercial GPS receivers. The implemented spoofing simulation system ran synchronized two GPS simulator modules in a single scenario to generate both of spoofing and GPS signals simultaneously. Because the signals are generated in radio frequency, a commercial GPS receiver can be tested using this system. Experimental test shows the availability of this system, and anti-spoofing performance of a commercial GPS receiver has been analyzed.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.112-119
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• 2023

In urban environments, signals of Global Positioning System (GPS) can be blocked and reflected by tall buildings, large vehicles, and complex components of road network. Therefore, the performance of the positioning system using the GPS module in urban areas can be degraded due to the loss of GPS signals necessary for the position estimation. To deal with this issue, various localization schemes using inertial measurement unit (IMU) sensors, such as gyroscope and accelerometer, and Bayesian filters, such as Kalman filter (KF) and particle filter (PF), have been designed to enhance the performance of the GPS-based positioning system. Among Bayesian filters, the PF has been widely used for the target tracking and vehicle navigation, since it can provide superior performance in estimating the state of a dynamic system under nonlinear/non-Gaussian circumstance. This paper presents a positioning system that uses the double-stacked particle filter (DSPF) as well as the accelerometer, gyroscope, and GPS receiver on the smartphone to provide higher pedestrian positioning accuracy in urban environments. The DSPF employs a nonparametric technique (Parzen-window) to create the multimodal target distribution that approximates the posterior distribution. Experimental results show that the DSPF-based positioning system can provide the significant improvement of the pedestrian position estimation in urban environments.

• Journal of Astronomy and Space Sciences
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• v.32 no.4
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• pp.403-409
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• 2015

The Quasi-Zenith Satellite System (QZSS), a dedicated regional Japanese satellite system currently under development, was designed to complement the performance of the Global Positioning System (GPS). The high elevation angle of the QZSS satellite is expected to enhance the effectiveness of GPS in urban environments. Thus, the work described in this paper, aimed to investigate the effect of QZSS on GPS performance, by processing the GPS and QZSS measurements recorded at the Bohyunsan reference station in South Korea. We used these data, to evaluate the satellite visibility, carrier-to-noise density (C/No), performance of single point positioning, and Dilution of Precision (DOP). The QZSS satellite is currently available over South Korea for 19 hours at an elevation angle of more than 10 degrees. The results showed that the impact of the QZSS on users' vertical positioning is greatest when the satellite is above 80 degrees of elevation. As for Precise Point Positioning (PPP) performance, the combined GPS/QZSS kinematic PPP was found to improve the positioning accuracy compared to the GPS only kinematic PPP.