• Journal of the Korean Association of Geographic Information Studies
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• v.8 no.3
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• pp.129-141
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• 2005

It is difficult to edit large-scale digital maps because of problems of cost and process and it is carried out by aerial photogrammetry in renewal periods. Five years of update period cannot provide exact data required in the fast-moving age. This study is to analyze applicability and impact for editing digital map of road system using the GPS-Van. Results are compared with accuracy of the data acquisition with GPS-Van positioning. INS data are affected by the barrier to receive GPS data. But high accuracy were achieved by thorough plans according to work order. By using GPS Van and fieldwork at the same time for editing and renewal of digital map, it is expected that this method can be used to reduce costs in the economic and temporal aspects, and provide rapid and accurate digital map of road system.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.2
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• pp.138-146
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• 2011

With the increased use of GPS in the field of various applications including surveying, the request for fast and precise positional information has increased. Several countries such as USA, Canada, and Australia have already been operating Internet-based automatic GPS data analysis system using e-mail and FTP. Expanding GPS market, it is necessary to establish automatic GPS baseline processing system that is accessible via Internet. The system developed in this study is operating on the web, and it allows the users to access easily regardless of time and place. The main processing engines are Bernese V5.0 and PAGES. They process user data with three GPS CORS(Continuously Operating Reference Station), and then send the report to the users through e-mail. This system allows users to process high accurate GPS data easily. It is expected that this system will be used for various GPS applications such as monitoring large-scale structures and providing spatial information services in private sector.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.353-356
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• 2005

In Taiwan, there are more the one hundred GPS tracking stations maintained by Ministry of the Interior (MOI), Academia Sinica, Central Weather Bureau and Central Geological Survey. In the further, they may be instead of the GPS controlling points after giving the lawful status. In other words, the engineers don't need to survey on the reference points when they are surveying in the field. They only need to download the GPS data via internet and process the observations in their company. The precise coordinates of the unknown points will be obtained. Therefore, the data qualities of the tracking stations are more and more important. In this study, six data quality indexes were adopted as follows: observations, cycle slips, multipath on L1, multipath on L2, clock offset and frequency stability. Besides, the relationships of the indexes and the positioning precision were found. The frequency stability of GPS receiver is the most important index, the cycle slip is the second index and the mutlipath is the third index. According to the results, the auto-analytical system of GPS data quality was established and the tracking stations were monitored. When the receiver got some problem or the station's environment changed, we hope to find and resolve the problems earlier to make sure the high data quality of the tracking stations. Moreover, we try to design a data quality verification to help users and let the engineers have more and more confidence when they use the data of GPS tracking stations.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2007.04a
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• pp.455-458
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• 2007

Currently, aortal surveying is getting advanced in the world. New digital equipment for aerial surveying makes improvement of accuracy, economical efficiency and reduces cost. for a result, however, there are required to produce a accurate product. In this study, we used two kinds of data, the one which used only GPS/INS data and the other one which used GPS/INS data added on GCPs from digital maps, and made as a mosaic to compare both of them whether which one is better based on digital maps. the result is that the data which used GPS/INS data added on GCPs from digital maps was a lot better than GPS/INS data.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.547-549
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• 2012

In this paper, we propose the verification platform for traffic information of TPEG. Verification platform contains the parsing module of TPEG data and the processing module of GPS data. We compared the traffic information of GPS devices with traffic information of TPEG data. As a result, traffic information from TPEG data is distinguished from actual road traffic information.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2632-2635
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• 2003

This paper designs a software signal generator for the new GPS L2 civil signal. The CM/CL code and the message structure of L2CS described in GPS ICD PPIRN-200C-007 are used in designing the signal generator. The output of the GPS signal generator is designed as the sampled IF data with the sampling frequency 5.7MHz and stored in the binary data format. By analyzing both the spectrum characteristics of the output signal and the correlation properties of the CM/CL code, the validation of the designed GPS signal generator is shown. It should be mentioned that the modeling of the GPS satellite constellation and the error sources remains for implementing the software space segment of GPS.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1636-1645
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• 2016

In navigation systems that use collected trajectory for routing, the number and diversity of trajectory data are crucial despite the infeasible limitation which is that all routes should be collected in person. This paper suggests an algorithm combining trajectories only by collected GPS data and generating new routes for solving this problem. Using distance between two trajectories, the algorithm estimates road intersection, in which it also predicts the correlated direction of them with geographical coordinates and makes a decision to combine them by the correlated direction. With combined and generated trajectory data, this combination way allows trajectory-based navigation to guide more and better routes. In our study, this solution has been introduced. However, the ways in which correlated direction is decided and post-process works have been revised to use the sequential pattern of triangles' area GPS information between two trajectories makes in road intersection and intersection among sets comprised of GPS points. This, as a result, reduces unnecessary combinations resulting redundant outputs and enhances the accuracy of estimating correlated direction than before.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.1
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• pp.71-78
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• 2009

In general, it is necessary to establish the dedicated GPS base station at the central point of the survey area in GPS/INS aerotriangulation. Although this base station is needed to achieve the required survey accuracy, there are some difficulties in practical operation. To tackle these difficulties and to achieve the effective GPS/INS aerotriangulation, the GPS data of CORS was interpolated and used in stead of those of the usual ground base station. Through this study, it was found that the interpolated CORS data was accurate enough to substitute dedicated GPS base station in GPS/INS aerotriangulation.

• Bulletin of the Korean Space Science Society
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• 2003.05b
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• pp.50-50
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• 2003

No Abstract, See Full Text

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.2
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• pp.381-389
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• 2012

This paper proposes a method which corrects location data of GPS for navigation of outdoor mobile robot. The method uses a Bayesian filter approach called the particle filter(PF). The method iterates two procedures: prediction and correction. The prediction procedure calculates robot location based on translational and rotational velocity data given by the robot command. It incorporates uncertainty into the predicted robot location by adding uncertainty to translational and rotational velocity command. Using the sensor characteristics of the GPS, the belief that a particle assumes true location of the robot is calculated. The resampling from the particles based on the belief constitutes the correction procedure. Since usual GPS data includes abrupt and random noise, the robot motion command based on the GPS data suffers from sudden and unexpected change, resulting in jerky robot motion. The PF reduces corruption on the GPS data and prevents unexpected location error. The proposed method is used for navigation of a mobile robot in the 2011 Robot Outdoor Navigation Competition, which was held at Gwangju on the 16-th August 2011. The method restricted the robot location error below 0.5m along the navigation of 300m length.