• Journal of Navigation and Port Research
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• v.27 no.3
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• pp.267-272
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• 2003

This paper describes design method of Passive-type Radar Reflector (PRR) which is to provide the requirement of newly revised 2000 SOLAS regulations on the Radar Reflector. The main target of this work is to find the optimum shape of a radar target having large Radar Cross Section (RCS). Through the RCS analysis based on the theoretical approach, two kinds of PRR models, RRR-F model for use in fisheries and PRR-S model for use in small sized ship, are designed and discussed their RCS performance. RCS measurement tests for the various sized samples are carried out in an anechoic chamber. As evaluation results it was clearly shown that the conventional sphere-type shows optimum shape in case of PRR-S, while the cylinder-type which consists of large sized corner clusters or zig-zag flat plats gives best performance in case of PRR-F.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2002.03a
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• pp.161-176
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• 2002

Collision avoidance is the most important part of a small vessel. Small and mediurn sized ships are surprisingly poor targets for radar reflection and are frequently in danger of being overrun by large vessels, even under good condition of visibility. One of the best way to prevent collisions at sea is to use as large and well designed a radar reflector. Thus, RCS(Radar Cross Section) increase is key element in the design of radar reflector. Radar Reflectors are normally classified into active-type and passive-type. In this paper, the RCS increase methods for passive-type reflector through shaping are explained, and analyzed with RCS performance test by computer simulation. As results from analysis, It is shown that the effective diameter of radar reflector is over 10 λ to provide a return above the threshold RCS of 25m$^2$, lower limit of detectability using X-band radar in a moderate sea.

• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.199-207
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• 2002

Radar Cross Sections(RCS) for the radar targets are measured and their performance characteristics are analyzed through computer simulation. In addition, constructional features for the commercial radar reflectors are investigated. Then, the optimum design condition of a passive-type radar reflector was chosen. The results show that the octahedral-type radar reflector with 10$\lambda$ sized circular plates has best performance in X-band($\lambda$=3.2cm). However, to comply with newly adopted 2000 SOLAS regulations, larger sized circular plate is required to provide at both X-band and S-band.

• Proceedings of KOSOMES biannual meeting
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• 2003.05a
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• pp.135-139
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• 2003

This paper describes on the development of Passive-type Radar Reflector for Fisheries (PRR-F) based on the newly revised 2000 SOLAS regulations. The purpose of PRR-F is to provide it as the protection devices of a fishing net and a fishing field. The PRR-F is composed of corner cluster bundle of light galvanized iron, and it is inserted into floating styrofoam. Performance tests for the PRR-F are carried out in an anechoic chamber. The test results show that the reflected radar signal from PRR-F is large enough for the purpose.

• Proceedings of KOSOMES biannual meeting
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• 2003.05a
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• pp.125-134
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• 2003

This paper describes on the design of Passive-type Radar Reflector for small Ship (PRR-S) based on the newly revised 2000 SOLAS regulations. The design idea, adopted in the study, is to hold PRR-S in the proper ‘catch rain’ position to avoid fluctuations of Radar Cross Section (RCS) due to ship's heeling. The PRR-S consists of octahedral-type radar reflector with circular plates and three-axis gimbaled stabilizer with weight on the bottom of outer gimbal ring. Performance test for the PRR is carried out in an anechoic chamber. The test results show that the reflected radar signal from PRR-S is more uniformly distributed than the reference model (Davis Echomaster).

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.667-676
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• 2009

The payload can be classified as a passive and active type. Generally radar satellite to acquire specific information through various radar images will use the SAR (Synthetic Aperture Radar) as active type payload. the principal of SAR satellite is to receive the signal returned from certain objects and/or surfaces in order to construct an radar image. The data acquired from the satellite in its real orbit shall be needed to perform successful CAL/VAL (Calibration & Validation) because the SAR satellite have to receive the returned signal for SAR image construction. In order to do the above, the returned signal shall be related to ground targets. Especially ground target is the corner reflector (CR) for CAL/VAL. Generally the reflector has various types and shapes. Their selection can be dependent on characteristics and mission objectives of SAR satellite. In this paper, reflector focused on the optimal case and effective case has been studied and then the trihedral corner reflector under this study has been designed and its performance also analyzed.

• Solar Energy
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• v.7 no.1
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• pp.3-13
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• 1987

A batch type passive solar water systems, which perform the dual function of absorbing the solar energy and storing the heated water, have been designed and fabricated for the purpose of side-by-side testing at KIER. The test models included an A, B and C type batch systems which were classified according to the design of box and arrangement of tanks. The year-round performance tests show that B type batch system taken the step-wise tank arrangement indicates 55.7% yearly-average collection efficiency factor and 61% yearly-average maximum collection efficiency factor. Computer-aided-experimental results show that the sufficient hot water can be obtained in the early morning if the glazing is supplemented by a reflector/insulation cover. The thermal performance equation has been developed for the prediction of hourly variation of the water temperature in tank.