• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.5
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• pp.92-98
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• 2008

Chaff is one of important devices for heliborne protection from radars and missiles. When we use a chaff for heliborne protection, J/S(jamming signal of chaff vs reflected signal from heliborne) is important factor to analyze a heliborne survive. When the radial angle between missile and heliborne is changed, J/S of missile receiver is changed and jamming effectiveness of chaff is also changed. We calculate the RCS of chaff and heliborne, and compare the returned signals in a half power beam width of receiver antenna. We analyze chaff dispense modes and specially simulate the effectiveness of a dilution mode chaff between missile and heliborne.

• Proceedings of the IEEK Conference
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• 2004.06a
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• pp.139-142
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• 2004

X-band Waveguide slot way antenna is developed for heliborne MTD radar applications. The antenna is composed of multi-layer waveguide structures. Each of them has it's own functions, such as, radiation, power/phase distribution, coupling, etc. Broad-wall offset slots are used for radiators, inclined slots on broad-wall for power distribution to radiating(branch) waveguide, some kind of coaxial probe structures for in-phase coupling and H-plane T-junction power dividers. Antenna is realized by precision machining and careful assembly. It is tested and measured by 3m${\times}$l.7m planar near-field probe, which is set-up in MTG. Far-field calculations have good agreement in tolerable bounds. Special but necessary process such as brazing, will increase the accuracy and performance. Results show promising possibilities of future applications for real systems.

• Journal of the Korea Institute of Military Science and Technology
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• v.11 no.6
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• pp.63-73
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• 2008

The helicopter position, heading data and the direction finding data of ESM are essentially required to compensate the parallax and analyze the direction finding accuracy of heliborne ESM in flight test phase. In the case of the long test range compared with small platform like as LYNX helicopter and Jisim Island test site, the parallax compensation for direction finding accuracy calculation and GPS position error can be neglected. In this paper, the direction finding accuracy on the basis of helicopter propeller was calculated by coordinate changing between helicopter and transmitting antenna from WGS84 coordinate to navigation coordinate using helicopter position and direction finding data.