신동호 Dong Ho Shin , 기창돈 Chang Don Kee

DOI: JANT Vol.2(No.1) 3-10, 1998

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GPS is one of the main navigation systems. In these days, the application scope of GPS is extended to attitude determination using Differential GPS(DGPS) technique and Cycle Ambiguity resolution technique. In this paper, we propose an attitude determination algorithm using Kalman filter through double differenced measurement equation which is not for users with GPS patch antennas, but for users with low-priced GPS receivers. This paper also shows the simulation results and the effectiveness of proposed algorithm.

안병철Bikerng Chearl Ahn,박승모Seung Mo Park,임태욱Tae Wook Lim

DOI: JANT Vol.2(No.1) 11-21, 1998

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There have been active research efforts in the development of a dual-use millimeter-wave radiometer as an aircraft landing aid in low visibility conditions. In this paper, we constructed a radiometer operating at the Ka-band where it is relatively easy to build RF components. The radiometer is used to collect radiometric signatures of some vehicles and land surfaces. Measured signatures suggest that vehicles with metallic surfaces yield signatures markedly different from nearby land surfaces so that they can easily be detected by a simple radiometer.

소원욱Won Wook So,강연덕Yeon Duk Kang,이택경Taek Kyung Lee

DOI: JANT Vol.2(No.1) 22-33, 1998

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In the coherent-on-receiver radar system using the magnetron source, frequency synthesizer is employed as a STALO(Stable Local Oscillator) to keep the intermediate frequency stable. In this paper, X-band(8.4GHz~9.7GHz) single loop frequency synthesizer is designed and implemented by an indirect frequency synthesis technique. Phase comparison is performed by a digital PLL(Phase-Locked Loop) chip and the loop filter is designed for the low phase noise. The effects of loop component characteristics on the output phase noise are analyzed for single loop structures, and the calculated results are compared with the measured data.

김경연Kyung Youn Kim

DOI: JANT Vol.2(No.1) 34-42, 1998

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An adaptive state and input estimator for the tracking of a target with unknown randomly switching input is developed. In modeling the unknown inputs, it is assumed that the input sequence is governed by semi-Markov process. By incorporating the semi-Markov probability concepts into the bayesian estimation theory, an effective adaptive state and input estimator which consists of parallel Kalman-type filters is obtained. Computer simulation results that the proposed adaptive estimator have improved tracking performance in spite of the unknown randomly switching input.

김인택In Teak Kim,이응기Eung Gi Lee,김웅수Woong Su Kim

DOI: JANT Vol.2(No.1) 43-52, 1998

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In this paper, we have investigated the effects of geographic information on the performance of multiple ground target tracking system using multiple sensors, Geographic information is utilized in two cases : association and masking target measurement. Virtually no improvement is observed to the overall performance of tracking system when we applied mobility to the association procedure. Masking target measurement based on mobility produces desirable result that the number of false tracks is reduced. Since geographic information can be regarded as an additional sensor in sensor fusion paradigm, careful usage is required.

홍교영Gyo Young Hong,윤경호Kyoung Ho Yoon,김유창Yoo Chang Kim,김원후Won Hoo Kim

DOI: JANT Vol.2(No.1) 53-60, 1998

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This paper descries some design concepts and design parameters of RZ-SSB which allows full carrier insertion into the single side band to overcome the severe fading in aeronautical telecommunication, and it is described in ARINC Spec. in the name of AME(AM Equivalent), and the necessary transmission bandwidth of RZ-SSB is similar to that of a aeronautical telecommunication. As an amplitude limiter manage to remove the amplitude fading without degrading the quality of output signal, the receiver acts like the FM demodulators. Using the digital Signal Processing (DSP) techniques in the design of transceiver systems has become a performance enhancement of the signal quality and reliability, and making use of DSP, it`s able to design low cost, compact transceiver and reduce its weight. For avionics systems is able to eliminate the inherent disadvantages in RZ-SSB, the results of experimental tests suggest that the adoption of RZ concepts is suitable for aeronautical telecommunication transceiver systems use in HF band.

조근식Geun Sik Jo,양종윤Jong Yoon Yang

DOI: JANT Vol.2(No.1) 61-67, 1998

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In this paper, we hae described the Ramp Activity Coordination Expert System (RACES) which can solve aircraft parking problems. RACES includes a knowledge-based scheduling problem which assigns every daily arriving and departing flight to the gates and remote spots with the domain specific knowledge and heuristics acquired from human experts. RACES processes complex scheduling problem such as dynamic inter-relations among the characteristics of remote spots/gates and aircraft with various other constraints, for example, custome and ground handling factors at an airport. By user-driven modeling for end users and knowledge-driven near optimal scheduling acquired from human experts, RACES can produce parking schedules of aircraft in about 20 seconds for about 400 daily flights, whereas it normally takes about 4 to 5 hours by human experts. Scheduling results in the form of Gantt charts produced by the RACES are also accepted by the domain experts. RACES is also designed to deal with the partial adjustment of the schedule when unexpected events occur. After daily scheduling is completed, the messages for aircraft changes and delay messages are reflected and updated into the schedule according to the knowledge of the domain experts. By analyzing the knowledge model of the domain expert, the reactive scheduling steps are effectively represented as rules and the scenarios of the Graphic User Interfaces (GUI) are designed. Since the modification of the aircraft dispositions such as aircraft changes and cancellations of flights are reflected to the current schedule, the modification should be notified to RACES from the mainframe for the reactive scheduling. The adjustments of the schedule are made semi-automatically by RACES since there are many irregularities in dealing with the partial rescheduling.