• Journal of Advanced Navigation Technology
• /
• v.20 no.3
• /
• pp.182-189
• /
• 2016

In this paper, we propose a buoy system based on multi-hop relay networks for ocean observation. The proposed system consists of various sensor modules, a gateway, wireless communication modules, and a remote monitoring site. The sensor modules are integrated with various communication interfaces and connected to the gateway of the proposed buoy system with an unified protocol based on controller area network (CAN)-bus. In order to communicate with the remote monitoring site and extend the coverage, the proposed system uses long-term evolution (LTE) router and XBee mesh network modules. The field test results show that the proposed system can extend the coverage using the proposed multi-hop relay network.

• Journal of Advanced Navigation Technology
• /
• v.19 no.5
• /
• pp.403-410
• /
• 2015

ADS-B can provide high accurate position information and faster update rate than Radar system and it is a technique that can supplement or replace the Radar. Recently ADS-B has been applied to the actual aircraft operation because to increase air transportation traffic and required to high accurate surveillance. In this study, we surveyed analysis of position deviation distribution analysis and received actual ADS-B trajectory data for conformed precise surveillance on the near airport area using ADS-B message. For that, we received the precision instrument approach ADS-B trajectory data using instrument landing system, and can analyse about target deviation distribution on the final approach segment about precision instrument approach. The result of analysis is mean distance of target deviation -0.04 m and standard deviation 6.71 m on between ADS-B target and extended runway centerline. Also that is to conformed the ADS-B message trajectory available to provide relatively exact surveillance information.

• Journal of Advanced Navigation Technology
• /
• v.19 no.5
• /
• pp.389-394
• /
• 2015

This paper considers the transfer alignment in the inertial navigation system which has lever-arm and the time delay in the velocity measurement. We suggest a method to improve the performance of the velocity matching. First, we analyze the estimation performance of the velocity matching through the tuning of the two covariance matrices of process noise and measurement noise. Next we provide some maneuvering conditions of the vehicles to improve the estimation performance using the observability analysis. The analysis results are verified using the computer simulations, which show that cruise movements do not provide the azimuth estimation of the vehicles, while east or north accelerating movement can provide.

• Journal of Advanced Navigation Technology
• /
• v.19 no.5
• /
• pp.363-369
• /
• 2015

This paper describes deployment of a sea based sensor platform for the detection of a submarine launched ballistic missile (SLBM). Recently, North Korea successfully conducted the underwater launching test of the SLBM, which will seriously threaten the global security. To defend these threats successfully, a sensor platform of the ballistic missile defense (BMD) should be deployed in the area of high detection probability of the missile. The maximum detection range characteristics of the typical radar sensor system, however, depend on the radar cross section (RCS) and flight trajectories of the target. In this point of view, this work analyzed the flight trajectories based on the tactics and calculated the RCS of the SLBM. In addition, sea based sensor platform position is proposed from the analysis of the detection time.

• Journal of Advanced Navigation Technology
• /
• v.15 no.1
• /
• pp.11-17
• /
• 2011

In this paper, we consider the frequency sharing feasibility of Fixed Satellite Service (FSS) with Microwave Landing System (MLS) allocated in the C-band. On the basis of characteristics of MLS and FSS suggested by ITU and safety standards of MLS by ICAO, three interference scenarios are built and numerical simulations are carried out for investigating the frequency sharing between the two systems. From the simulation results, we calculate the separation distance between MLS and FSS ground antennas, required for frequency sharing by employing standard protection limits regulating the interference to noise ratio (I/N) of the receiver.

• Journal of Advanced Navigation Technology
• /
• v.15 no.6
• /
• pp.1241-1249
• /
• 2011

There are TOA, TDOA and AOA method to estimate the position of the electromagnetic wave transmitter by using the multiple receivers at the fixed position. Among these methods, AOA method is suitable for the jammer localization system. Because TOA method can be adopted for the clocks of the transmitter and the receiver are synchronized each other, and TDOA method can be only adopted for a broad-band jamming signal. This paper, therefore, analyzes the characteristics of the AOA measurements and the sensitivity of the positioning performance according to the system design parameters. Based on the analyzed results, the jammer localization system to meet the desired performance is designed, and it has been checked that the positioning error for the jammer located at a distance of 10km is lower than 38m through the simulation results.

• Journal of Advanced Navigation Technology
• /
• v.15 no.6
• /
• pp.1059-1067
• /
• 2011

Next-Generation ITS environment requires high-speed data packet transmission, security, authentication, and hand-over supportable for driving vehicle on road by installing RSEs and OBUs. Therefore, wireless communication technology for next-generation ITS services are advancing to 200km/h maximum speed supportable, 1km communication radius, minimum 10Mbps hish-speed datarate for multimedia data(such as text, images, movie clips and so on) supportable, high reliability. In this paper, we implemented WAVE communication system which based on IEEE 802.11p PHY/MAC and evaluated that the system meets next-generation ITS environments.

• Journal of Advanced Navigation Technology
• /
• v.13 no.3
• /
• pp.393-398
• /
• 2009

In this paper, we study the design and implementation of an auto recognition system by using wireless sensor node. RFID system has a limited communication range and communication network is damaged, it is impossible to communicate. Therefore, easy installation and low cost wireless system are required in an area where the installation of communication between RFID system and monitoring system is difficult, or a portable RFID system is installed. The auto recognition system in this study is implemented by the combination of 13.56MHz RFID system using MLX12115 RFID chip of Melexis company and wireless sensor node system using CC2420 Zigbee chip of Chipcon company. As a result, we develop an auto recognition system which makes it possible to get tag's information wirelessly. Also, it has a simple circuit structure and is small in size.

• Journal of Advanced Navigation Technology
• /
• v.20 no.6
• /
• pp.588-594
• /
• 2016

As more populations are getting older, the number of vulnerable pedestrians is increasing, thereby social problems related to transportations also frequently occur in different areas and situations. Many of such problems come from bus drivers who may pass bus stops not recognizing passengers about to board. In this paper, we propose a new IoT bus notification system developed to avoid these situations. Our implementation aims to gain bus service routes using publicly opened data, notify passengers about bus stop locations using GPS information and finally deliver the positions of those passengers to the bus drivers so that they can hardly miss passengers who are willing to board on the right stop. By creating an application, it was conducted by means of a GPS to communicate the location of the vehicle by means of GPS and transfer data to the location of the vehicle. Experimental results show that it is possible to accurately determine the position of passengers even in a crowded race area. The average error distance is 31m, and if the data to be processed as error is excluded, it provides a high reliability as 19m.

• Journal of Advanced Navigation Technology
• /
• v.21 no.1
• /
• pp.12-20
• /
• 2017

A maritime DGPS in Korea offers pseudo-range correction information and monitors integrity of correction data by using multiple GNSS receivers. The maritime DGPS reference station and integrity monitor service sets alarm threshold value about integrity monitoring parameters for preventing service interruption status. However there is no way to avoid system interruption according to malfunction of backup systems and outside factors. Therefore, in this paper, warning threshold values were proposed for maritime DGPS operator can be counteract in advance. And Markov analysis method was carried out for selection of these warning threshold values.