• Journal of the Korea Society of Computer and Information
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• v.28 no.2
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• pp.63-68
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• 2023

In this paper, we introduce a system that tracks and shares the position of objects based on tags. After receiving the location information of objects through the tag location tracking app, the location of the tag is shared as a group, and the shared users also check the location of objects in real time. Our system offer a differentiated function that allows multiple users to manage and supervise the location of objects, compared to legacy systems. The GPS module and Bluetooth are connected to the Arduino board to obtain the location information of the tag and check it through the Android app. We used Android Studio to create app, and the tag brings up the location of the object. The location of the tag is stored in the phpMyadmin DB and the latitude/longitude is received to the Android app and displayed on the map of the app. The proposed system will be useful for loss prevention and managing public goods.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.9
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• pp.2120-2126
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• 2010

This paper aims to realize the location tracking system using the Zigbee in the wireless sensor network. The wireless sensor network offers the user-oriented location tracking service in the ubiquitous environment. The location tracking service can track the location of an object or a person and provides it. The location tracking system realized in this paper can be used inside or outside without any black-out areas to measure the location of the moving nodes. In tracking inside the RSSI signals use and in tracking outside will connect with the GPS signals to track the location. Also, by using Zigbee, the wireless sensor network environment was established and by obtaining the location of the moving nodes, the real-time tracking is possible.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.4
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• pp.307-313
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• 2021

Modernized GNSS signal structures tend to use tiered codes, and all GNSSs use binary codes as secondary codes. However, recently, signals using polyphase codes such as Zadoff-Chu sequence have been proposed, and are expected to be utilized in GNSS. For example, there is Tiered Differential Polyphase Code (TDPC) using polyphase code as secondary code. In TDPC, the phase of secondary code changes every one period of the primary code and a time-variant error is added to the carrier tracking error, so carrier tracking ambiguity exists until the secondary code phase is found. Since the carrier tracking ambiguity cannot be solved using the general GNSS receiver architecture, a new receiver architecture is required. Therefore, in this paper, we describe the carrier tracking ambiguity and its cause in signal tracking, and propose a receiver structure that can solve it. In order to prove the proposed receiver structure, we provide three signal tracking results. The first is the differential decoding result (secondary code sync) using the general GNSS receiver structure and the proposed receiver structure. The second is the IQ diagram before and after multiplying the secondary code demodulation when carrier tracking ambiguity is solved using the proposed receiver structure. The third is the carrier tracking result of the legacy GPS (L1 C/A) signal and the signal using TDPC.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.8
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• pp.761-766
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• 2008

This paper analyzes the availability and Dilution Of Precision (DOP) of GPS, widely used in positioning, with and without augmentation using QZSS (Quasi-Zenith Satellite System). Orbit simulator for QZSS is developed using Kepler‘s orbital parameters. Also 3D modeling technique based on three-Dimensional GIS digital map and satellite tracking algorithm for visible satellite simulation system are discussed. Performance improvement of the availability and DOP were achieved by combining GPS with QZSS at urban environment of Seoul.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.394-396
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• 2006

When developing a new GPS receiver module, the essential problems are evaluation of reliable algorithms, software debugging, and performance comparison between algorithms to find optimal solution. Most GPS receiver modules nowadays use a correlator to track signals from satellites and an MCU (Micro Controller Unit) to control operations of the entire module. The problem of software evaluation from MCU is very difficult, due to limitation of MCU resources and low ability of interfacing with user. Normally, user has to expense special tool kit for a limiting access to MCU but it is also hard to use. This article introduces an implementation of a GPS receiver test bed using correlator GP2021 interfacing with ISA (Industry Standard Architecture) PC bus. This way can give user complete control and visibility into the operation of the receiver, then user can easily debug program and test algorithms. For this article, the least square method is implemented to test the hardware and software performance.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.2
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• pp.137-141
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• 2006

The purpose of GPS structural vibration monitoring is to obtain information on the frequency and amplitude of vibrations based on GPS observations that are often affected by various errors. Filters are frequently used to improve GPS accuracy and to retrieve vibration signals from GPS observational series. This paper studies the performances of four commonly used filters, i.e., Vondrak, wavelet, adaptive FIR and Kalman filters, for such applications. Controlled experiments are carried out and the results show that the capability of GPS in tracking structural dynamics and complex signals can be improved with any of the filters. The performances of Vondrak and wavelet filters are almost the same and superior to the adaptive FIR and Kalman filters. Recommendations are given for the selection of filters and filter parameters for different situations based on an analysis of the advantages and disadvantages of each of the filters.

• The Journal of the Convergence on Culture Technology
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• v.1 no.1
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• pp.79-85
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• 2015

According to the growing use of the personal GPS in the mobile device recently, the LBS (Local bases service), which processes and refines the GPS information, such as a position-tracking service, a public safety service, a local based information service, has increased steadily. Due to the refraction or reflection of GPS, however, it is impossible to use GPS around or in buildings. Therefore, it is necessary to correct the errors of GPS. We propose the method which corrects the errors of GPS and creates the refined trajectory using intersection region indexing. After analyzing the trajectory, receiving trajectories from many people and identifying the similarity between of trajectories, we will recommend the favorite route and useful information such as restaurant, convenience store, bus station and emergency call service.

• Journal of the Korean Institute of Telematics and Electronics S
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• v.34S no.1
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• pp.16-25
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• 1997

This paper shows the development of the high accuracy vehicle positioning algorithm using the differential technique in vehicle tracking systems form the existing vehicle position which is acquired from the global positioning system (GPS). The control center receives the satellite ephemerise data and pseudorange correction from the reference station, and vehicle position from the moving vehicle. The pseudorange is calculated with the satellite position and the vehicle position, and corrected by pseudorange correction. Using this corrected pseudorange and kalman filter, more improved vehicle positioning data were obtained.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.6
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• pp.121-130
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• 2009

In this paper, Gaussian probability distribution model based multi-sensor data fusion algorithm is proposed for a vehicular location awareness system. Conventional vehicular location awareness systems are operated by GPS (Global Positioning System). However, the conventional system is not working in the indoor of building or urban area where the receiver is difficult to receive the signal from satellites. A method which is combined GPS and UWB (Ultra Wide-Band) has developed to improve this problem. However, vehicular is difficult to receive seamless location information since the measurement systems by both GPS and UWB convert the vehicle's movement information separately at each sensor. In this paper, normalized probability distribution model based Hybrid UWB/GPS is proposed by utilizing GPS location data and UWB sensor data. Therefore the proposed system provides information with seamless and location flexible properties. The proposed system tested by Ubisense and Asen GPS in the $12m{\times}8m$ outdoor environments. As a result, the proposed system has improved performance for accurateness and connection ability between devices to support various CNS (Car Navigation System).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.7
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• pp.1544-1550
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• 2013

In recent years, Container Security Device(CSD) using GPS & GLONASS to improve logistics efficiency are being extensively researched. The purpose of this paper is to examine the performance development antenna usable cargo container security transport. Antenna developed by study were optimized to match logistics environment apply to GPS/GLONASS dual frequency for monitering system. The measure of antenna have confirmation about frequency characteristics each 1575.42MHz, 1602MHz and VSWR is 2:1 measured in return loss -9.54dB. Reliability of this antenna has been verified about GPS/GLONASS through test-operation between the south korea and Russia.