This paper describe the method and the result of making a fiber optic gyrocompass measuring the heading angles of a ship with a fiber optic sensor. As the method seeking for the heading angles, it is possible to get the heading angles by measuring the output signals from a stationary fiber optic sensor in at least three directions such as a heading direction and other two directions having phase difference Φ1 and Φ2 to the heading. We made the static fiber optic gyrocompass by a high performance fiber optic sensor having scale factor of 210mV/deg/s and resolution of 0.5deg/hr using this principle. The accuracy of this system was 0.29˚ from 20 numbers of data measuring the arbitrary heading angle.

The purpose of this reserch is the development of 406MHz satellite EPIRB terminals which is used on Cospas/Sarsat system. This equipment is essencial facility in all vessel due to should be equipped according to GMDSS. This 406MHz satellite EPIRB needs high technology of complicated. Because, this is designed to operate stably with ultra-stability oscillator and with the low power consumption so that can operate continually for 48 hours by the contained battery. The development of this equipment is significant in the sides of acquirement of new technology on satellite communication fields. In this research, we investigated the international and domestic regulations of needed. Because this equipment is international system concerned with life of man. So, we designed the adequate hardwares and softwares from this research. From this research, we developed the equipment with appopriate capability for productions, and much more research is needed to develop the more small size more chip one for production.

This is the first report about the development of INMARSAT-C Satellite communication terminal. We analyze the existing Inmarsat-C terminal and examine each rules(IMO rule, domestic rules) about terminal. With that result, we design the basic hardware and software of terminal. This report consists of ; 1) the contents of the overall of operating situation and resources of INMARSAT-C system as like operation of communication system, communication channels and services 2) the contents of the specification of Inmarsat-C terminal hardware and software and the rules of IMO and Type approval 3) the design of basic hardware and reserch of signal modulation/demodulation using Viterbi algorithm 4) the design of software algorithms and functions focused in korean situations.

In this study, a vertical type LPE system has been developed for III-V semiconductor compounds single crystal growth. On the basis of the experience & basic study using this system, the system modification has been carried out for a ultra thin multi-layer single crystal. The temperature fluctuation was within ±0.006℃ at 800℃, temperature uniformity for graphite boat around was within ±0.15℃ at 650℃, and cooling rate was controllable from 2.2℃/min to 0.05℃/min. As a result it is considered to satisfy the condition to grow a ultra thin layer single crystal of III-V semiconductor compounds.

Various types of optical gyroscopes have been proposed and researched to the present in the world. This paper provides an overview of the types of optical gyroscopes, and also introduces technical principles, characteristics, advantages and disadvantages for each type. Moreover, the critical problems in a design have been discussed.

Fiber optic gyroscopes must be a promising technology that can replace conventional mechanical ones based on the principle of inertia of spinning masses. The advantages of fiber optic gyroscopes over mechanical ones include low cost, light weight, compact size and fast turn-on time. We will apply them to fiber optic gyrocompass for ships. Fiber optic gyrocompass for ships requires the north-seeking accuracy of 15˚/hr, earth rotation rate, or better. This article introduces the fiber optic gyroscope as rotation sensor in the fiber optic gyrocompass system for ships that is planed to develop in our laboratory.

Shortening the lasing wavelength(particularly below infrared ; the visible region) of laser diodes is very attractive because it can provide a wide range of applications in the fields of optical information, measurement, sensor, the development of medical instrument, and optical communication through plastic fibers. According to the recent researches on the field, InGaAsP/GaAs was suggested as a material for red-light laser. In this study, in order to grow InGaAsP/GaAs epitaxial layer on InGaAsP/GaAs by LPE, we used GaP and InP two phase solution technique for 670nm and 780 nm region, respectively. Through the X-ray diffraction measurement for the epitaxial layer grown from the experiments, we found that the lattice mismatch of In0.46Ga0.54As0.07P0.93/GaAs and In0.19Ga0.81As0.62P0.38/GaAs was about +0.3% and +0.1%, respectively.

Since it is very important for an ocean-going vessel to transmit information quickly and accurately to her owner or charterer not only for the ship's safety but for economic operation of the ship, some newly-built automated vessels equipped with automatic information transmission system which consists of INMARSAT-C and specially-designed computer. This system, however, is not applicable to the existing vessel without chaging her equipments and, furthermore, is too expensive for small shipping companies to fit out such a system on their vessels. Therefore, we propose a low-priced information transmission system which consists of a personal computer and communication equipments in the existing vessel, and in this paper, as the groundwork of the proposed system, we have made up the ship's position transmission system which is composed of and IBM AT-compatible, PC, INMARSAT-A and a GPS receiver. As the test result of the system through sea trial on the training ship 'HANBADA', we confirmed that transmission of the ship's position was achieved succesfully and consequently there could be high possibility of cost-effectiveness of the proposed system

In order to grow InGaAsP epitaxial layer on GaAs by LPE, an accurate phase diagram for In-Ga-As-P quarternary compounds is required. But the short wavelength InGaAsP/GaAs phase diagram for full wavelength range was not yet reported. In this study, therefore, a theoretical calculation has been carried out by using thermodynamic's equation for InGaAsP/GaAs in order to get the relation between the mole fraction of the sloute and solid phase compounds. And the calculation being compared with the dta of Kawanishi et. al, the result has been shown that his phase diagram obtained by the calculation can apply to growing InGaAsP/GaAs by LPE.

In this paper the results for thin multi-layer InGaAsP(1.3μm)/InP crystal growth by vertical liquid epitaxial growing furnance have been presented. The growth rates of InGaAsP layer and InP layer at cooling rate of 0.3℃/min and the growing temperature of 630℃ were obtained as 0.11 μm/min and 0.06 μm/min, respectively, by the uniform cooling with two phase solution technique.

Radar image data were collected through the on-line data acquisition system of A/D converter and personal computer, and the image was restorated on CRT or plotter after digital image processing of the data. The digital image processing system which was developed for this study, consisted of some kinds of software as follows : rearrangement, transformation, and enhancement of the image data in real space or frequency space by Fourier transform, edge detection of the image, compact processing, state inferential processing, and so on. Since the image of PPI radar sweeps from the center to the circumference of a circle, the image within a given period has the shape of fan. Therefore the acquired data were transformed to have the same interval as that of data in outmost concentricity. The results of various image processing methods using transformed data were better than those of the methods using original data.