• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.6
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• pp.714-721
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• 2024

For weight reduction we have applied Ti-6Al-4V, a lightweight and high-strength material, to a high-pressure gas cylinder for rapid cooling airborne electro-optical/infrared sensors. We have designed, manufactured using electron beam welding, and evaluated various performance(e.g., proof pressure tests, cooling tests). As results, a weight reduction of approximately 29 % was achieved compared to the previous gas cylinder made of STS630. Additionally, representative micro-structures that improve mechanical properties, such as acicular α' phase Martensite and Widmanstatten structure, were observed in the fusion zone. Furthermore, the cooling performance was successfully met under even high-temperature conditions.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.6
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• pp.793-799
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• 2014

EO GRD(Ground Resolved Distance) resolution of airborne EO/IR(Electro-Optical/Infrared) sensor is a critical factor in test and evaluation for EO sensor performance. We propose the laboratory measurement set-up for EO GRD by constructing optical collimator which includes integrated sphere, blackbody, equivalent 3-bar target and 6 DOF motion simulator. GRD is measured in the photographic imagery of bar targets by 3 different distances for 3 EO/IR sensors and the measured results were analyzed statistically. We found that at least 7 sheets of imagery are needed in order to obtain meaningful EO GRD. The result of statistical analysis shows that the distribution of the measured GRD is nearly symmetric about the average GRD, and the better imagery ratio above the average GRD is about 40~70%. Also from the best GRD analysis, it is estimated that the design goal for EO GRD should be 30% superior to the required GRD.