• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
• /
• 2009.04a
• /
• pp.129-132
• /
• 2009

Automatic target recognition surveying method is very important technology one-man surveying system. But in the case of loss of prism's position, it have to be re-tracking for searching it, consuming the searching time and complicated in processing. In this study, it is proposed new GPS receiver combination technology for orientation of both. In conclusion, the robotic TS(totalstation) is well assisted by absolute coordinates from single GPS receiver and multi-functional surveying instrument.

• International Journal of Control, Automation, and Systems
• /
• v.3 no.1
• /
• pp.15-31
• /
• 2005

Nowadays, the road safety is an important research field. One of the principal research topics in this field is the vehicle localization in the road network. This article presents an approach of multi sensor fusion able to locate a vehicle with a decimeter precision. The different informations used in this method come from the following sensors: a low cost GPS, a numeric camera, an odometer and a steer angle sensor. Taking into account a complete model of errors on GPS data (bias on position and nonwhite errors) as well as the data provided by an original approach coupling a vision algorithm with a precise numerical map allow us to get this precision.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• v.2
• /
• pp.482-485
• /
• 2006

다채널 시각비교 수신기(R100-40T, Euro-80)를 이용한 GPS C/A 코드 시각비교 데이터와 Ashtech Z12T 수신기를 이용한 P3 코드 시각비교 데이터를 통합 모니터링함으로서, 간편하게 시각비교 결과를 확인 할 수 있게 GUI(Graphic User Interface) 환경으로 구현하였다. 수신기들은 현재 KRISS(Korea Research Institute of Standards and Science)에서 사용 중인 위성이용 시각비교 수신기들이다. 본 시각비교 통합 모니터링 프로세스를 통해서 GPS C/A code 시각비교 데이터와 P3 code 시각비교 데이터 각각을 비교 분석함으로써 시각비교 결과의 신뢰성을 검증하는데 사용한다.

• Journal of Positioning, Navigation, and Timing
• /
• v.12 no.1
• /
• pp.59-65
• /
• 2023

A GNSS receiver must perform signal acquisition to estimate the code phase and Doppler frequency of the incoming satellite signals, which are essential information for baseband signal processing. Modernized GNSS signals have different modulation schemes and long PRN code lengths from legacy signals, which makes it difficult to acquire the signals and increases the computational complexity and time. This paper proposes a novel FFT/Inverse-FFT with baseband resampling to resolve the aforementioned challenges. The suggested algorithm uses a single block only for the FFT and thereby requires less hardware resources than conventional structures such as Double Block Zero Padding (DBZP). Experimental results based on a MATLAB simulation show this algorithm can successfully acquire GPS L1C/A, GPS L2C, Galileo E1OS, and GPS L5.

• International Journal of Computer Science & Network Security
• /
• v.23 no.3
• /
• pp.203-207
• /
• 2023

A frequency reconfigurable antenna based on graphene and used for multi-band wireless communications is presented in this article. The proposed antenna, which consists of two radiating rectangular loops with a graphene extension, is analyzed for Global Positioning System (GPS) and Iridium applications. Its operating frequency is tuned through the implementation of a layer of graphene and thereby adjusting the applied gate bias. Furthermore, the results show a novel use of graphene for microwave frequencies while achieving a frequency reconfiguration with an improvement of the impedance matching and the gain. The results also prove the importance of graphene, with its exceptional properties, for a promising future in nano-electronics.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.8 no.1
• /
• pp.88-95
• /
• 2005

Direct Georeferencing by combined multi-sensor based on the direct measurement of the projection centers and rotation angle of sensor through loading the GPS and INS in aircraft. The method of combined multi-sensor can offer us to acquire the exterior orientation parameters with only minimum GCPs, even the ground control process could be completely skipped. Consequently, It is possible extreme to reduce the time and expense for the mapping process. In this study, a CCD camera is simultaneously used in combined multi-sensor surveying, and acquired CCD image through Direct Georeferencing produce digital orthoimage. In this process, methods of combining sensor and digital orthoimage are examined and estimated. For the comparison of the positioning accuracy digital orthoimage through Direct Georeferencing, GCPs determined by GPS surveying are used. Two digital orthoimage are produced; one with a few GCP and the other without them. The accuracy of orthoimages produced through combined multi-sensor with GCPs meets that of 1:1,000 maps. Without GCPs, it meets that of 1:5,000 maps.

• Journal of Navigation and Port Research
• /
• v.29 no.1 s.97
• /
• pp.91-96
• /
• 2005

The National Marine Electronics Association(NMEA) is nonprofit-making cooperation composed with manufacturers, distributors, wholesalers and educational institutions. We use the basic port of equipment in order to process the signal from NMEA signal using equipment. When we don't have enough one, we use the multi-port for processing. However, we need to have module development simulation which could multiplex and provide NMEA related signal that we could solve the problems in multi-port application and exclusive equipment generation for a number of signal. For now, we don't have any case or product using NMEA multiplexer so that we import expensive foreign equipment or embody NMEA signal transmission program like software, using multi-port. These have problems since we have to pay lots ci money and build separate processing part for every application programs. Besides, every equipment generating NMEA signal are from different manufactures and have different platform so that it could cause double waste and loss of recourse. For making up for it, I suggest the NMEA multiplexer embodiment, which could independently move by reliable process and high performance single hardware module, improve the memory efficiency of module by designing the optimized Queue, and keep having reliability for realtime communication among the equipment such as main input sensor equipment Gyrocompass, Echo-sound, and GPS.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.4
• /
• pp.567-572
• /
• 2016

Many studies have been performed since the introduction of GPS in Korea. As a result, positioning using GNSS was fully proposed. On the other hand, most of these studies focused on accuracy but analytical studies on the GNSS status and the national GNSS infrastructure of Korea are lacking. In this study, the status of multi-constellation GNSS and National Geographic Information Institute's CORS (Continuous Operating Reference Station) were identified for the benefit and direction of GNSS infrastructure enhancement. As a result, it has been operating Multi-constellation GNSS, such as GPS, GLONASS, Galileo, COMPASS, and QZSS for surveying. In addition, improvement was presented by the number of satellites, precision, PDOP, etc. through the experiment about VRS and RTK using Multi-constellation GNSS. Upgrading the infrastructure for satellite surveying was identified as a priority consideration. In the future, if a Multi-constellation GNSS service is possible in VRS service, the satisfaction of public administration service will improve, which will contribute greatly to the advancement of a surveying infrastructure.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1234-1238
• /
• 2005

As the low power GPS signal is susceptible to interference, interference can seriously degrade the performance of GPS receiver. This paper designs a ANIEF(Adaptive Narrowband Interference Excision in Frequency domain) filter that removes narrow band interferences with low signal loss. This filter uses the pre-correlation technique and attempts to filter out the interference in the frequency domain. The interference excision performance of the designed filter is evaluated for various interferences using the ANIEF filter inserted GPS software receiver and the interference generator. Interferences considered in this paper are single-tone CWI(Continuous Wave Interference), multi-tones CWI, pulsed CWI, and swept CWI. The narrowband interference excision filter in frequency domain is very effective against various interferences and the strong interference with a simple structure. However, the signal power loss is unavoidable while transforming. In this paper, the hamming window and overlap technique are adopted to reduce the signal power loss. Finally, the interference excision performance and the reduced signal power loss of the ANIEF filter are shown.

• Korean Journal of Remote Sensing
• /
• v.26 no.6
• /
• pp.629-644
• /
• 2010

A real-time image georeferencing system requires all inputs to be determined in real-time. The intrinsic camera parameters can be identified in advance from a camera calibration process while other control information can be derived instantaneously from real-time GPS/INS data. The bottleneck process is tie point acquisition since manual operations will be definitely obstacles for real-time system while the existing extraction methods are not fast enough. In this paper, we present a fast-and-automated image matching technique based on the KLT tracker to obtain a set of tie-points in real-time. The proposed work accelerates the KLT tracker by supplying the initial guessed tie-points computed using the GPS/INS data. Originally, the KLT only works effectively when the displacement between tie-points is small. To drive an automated solution, this paper suggests an appropriate number of depth levels for multi-resolution tracking under large displacement using the knowledge of uncertainties the GPS/INS data measurements. The experimental results show that our suggested depth levels is promising and the proposed work can obtain tie-points faster than the ordinary KLT by 13% with no less accuracy. This promising result suggests that our proposed algorithm can be effectively integrated into the real-time image georeferencing for further developing a real-time surveillance application.