• Korean Journal of Optics and Photonics
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• v.18 no.2
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• pp.135-141
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• 2007

This paper describes the design technology for a third generation thermal imaging system, which is more compact than before, using a $320\times240$ mid-IR focal plane detector. The third generation non-scanning thermal imaging system was constructed as a compact thermal imaging module as a reconnaissance, surveillance and navigation sensor for helicopter and infantry vehicles in the $1980's\sim1990's$ and now, we designed a new compact infrared camera and studied a new type of non-uniformity correction lens fer this camera.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.8B
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• pp.1593-1600
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• 1999

This paper describes the acquisition modeling of an airborne target for target tracking simulation of infrared homing missiles. The modeling, of which key technologies are the sub-modeling for target infrared signature, atmospheric transmission, and receiver characteristics, shows the acquisition process of an airborne target under various tracking conditions determined by line-of-sight, distance, and atmospheric conditions. We confirm the validity of the modeling by applying it to simulations concerned with target tracking. The modeling gives a guideline to determine an optimum detector and a defection band for effective discrimination of the target among false targets.

• Current Industrial and Technological Trends in Aerospace
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• v.7 no.2
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• pp.48-58
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• 2009

Since 1960s, cryogenic cooling technologies has been adopted in the development of spacecraft with components that must be cooled to cryogenic temperatures of 2 to 150 K. In recent years this technology has been a substantial growth in the emerging number of programs that include such spacecraft to service scientific, military, and weather observation missions. The cooling of optics and detectors to reduce signal noise in infrared (IR) telescopes is the principal applications of cryogenic cooling technologies. The choice of cooling technologies depends on the desired temperature level, the amount of heat to be removed, and the required operating life. This paper will present the status of modern cryogenic cooling technologies especially for space application.

• Journal of Astronomy and Space Sciences
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• v.28 no.3
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• pp.225-232
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• 2011

We have designed and manufactured the Earth observation camera (EOC) of multi-purpose infrared imaging system (MIRIS). MIRIS is a main payload of the STSAT-3, which will be launched in late 2012. The main objective of the EOC is to test the operation of Korean IR technology in space, so we have designed the optical and mechanical system of the EOC to fit the IR detector system. We have assembled the flight model (FM) of EOC and performed environment tests successfully. The EOC is now ready to be integrated into the satellite system waiting for operation in space, as planned.

• Korean Journal of Optics and Photonics
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• v.33 no.4
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• pp.146-158
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• 2022

The detector of a focal-plane-array mid-wave infrared (MWIR) camera has different response characteristics for each detector pixel, resulting in nonuniformity between detector pixels. In addition, image nonuniformity occurs due to heat generation inside the camera during operation. To solve this problem, in the process of camera manufacturing it is common to use a gain-and-offset table generated from a blackbody to correct the difference between detector pixels. One method of correcting nonuniformity due to internal heat generation during the operation of the camera generates a new offset value based on input frame images. This paper proposes a technique for dividing an input image into block image patches and generating offset values using only homogeneous patches, to correct the nonuniformity that occurs during camera operation. The proposed technique may not only generate a nonuniformity-correction offset that can prevent motion marks due to camera-gaze movement of the acquired image, but may also improve nonuniformity-correction performance with a small number of input images. Experimental results show that distortion such as flow marks does not occur, and good correction performance can be confirmed even with half the number of input images or fewer, compared to the traditional method.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.3
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• pp.428-435
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• 2002

Pyroelectric $Pb(Zr_{0.3}Ti_{0.7})O_3$ (PZT30/70) thin film IR detectors has been fabricated and characterised. The PZT30/70 thin film was deposited onto $Pt/Ti/Si_3N_4/SiO_2/Si$ substrate by the sol-gel process. Four different substrate conditions were studied for their effects on the pyroelectric responses of the IR detectors. The substrate conditions were the combinations of the Si etching and the Pt/Ti patterning. In the Si etched substrate, the $Si_3N_4/SiO_2$ composite layer was used as silicon etch-stop, and was used as the membrane to support the PZT pyroelectric film element as well. The measured pyroelectric current and voltage responses of detectors fabricated on the micro-machined thin $Si_3N_4/SiO_2$ membrane were two orders higher than those of the detectors on the bulk-silicon. For detectors on the membrane substrate, the Pt/Ti patterned detectors showed a 2-times higher pyroelectric response than that of not-patterned detectors. On the other hand, the pyroelectric response of the detectors on the not-etched Si substrate was almost the same, regardless of the Pt/Ti patterning. It was also found that the rise time strongly depended on the substrate thickness: the thicker the substrate was, the longer the rise-time.

• Publications of The Korean Astronomical Society
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• v.21 no.2
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• pp.67-74
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• 2006

We have developed a control electronics system for an infrared detector array of KASINICS (KASI Near Infrared Camera System), which is a new ground-based instrument of the Korea Astronomy and Space science Institute (KASI). Equipped with a $512{\times}512$ InSb array (ALADDIN III Quadrant, manufactured by Raytheon) sensitive from 1 to $5{\mu}m$, KASINICS will be used at J, H, Ks, and L-bands. The controller consists of DSP(Digital Signal Processor), Bias, Clock, and Video boards which are installed on a single VME-bus backplane. TMS320C6713DSP, FPGA(Field Programmable Gate Array), and 384-MB SDRAM(Synchronous Dynamic Random Access Memory) are included in the DSP board. DSP board manages entire electronics system, generates digital clock patterns and communicates with a PC using USB 2.0 interface. The clock patterns are downloaded from a PC and stored on the FPGA. UART is used for the communication with peripherals. Video board has 4 channel ADC which converts video signal into 16-bit digital numbers. Two video boards are installed on the controller for ALADDIN array. The Bias board provides 16 dc bias voltages and the Clock board has 15 clock channels. We have also coded a DSP firmware and a test version of control software in C-language. The controller is flexible enough to operate a wide range of IR array and CCD. Operational tests of the controller have been successfully finished using a test ROIC (Read-Out Integrated Circuit).

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.1025-1026
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• 2008

This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The micro-controller calculates the 3D position of the markers using only the measured intensity and the 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system has the advantages of the compact size, the low cost, the easy installation, and the high frame rates to be suitable for high speed motion tracking in games.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.31.4-32
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• 2016

Observing the solar atmosphere with ground-based telescopes in the near-infrared has a number of advantages when compared to classical measurements in visible wavelengths. One of them comes from the magnetic sensitivity of spectral lines, which varies as ${\lambda}_g$, where g is the effective $Land{\acute{e}}$ factor of the transition. This wavelength dependence makes the near-infrared range adequate to study subtle spatial or temporal variations of the magnetic field. Spectral lines, such as the photospheric Fe I $1.5648{\mu}m$ spectral line, with a $Land{\acute{e}}$ factor g=3, have often been used in the past for this type of studies. To study the chromosphere, the Ca II IR triplet and the He I $1.0830{\mu}m$ triplet are the most often observed lines. The latter has the additional advantage that the photospheric Si I $1.0827{\mu}m$ is close enough so that photosphere and chromosphere can be simultaneously recorded with a single detector in a spectrograph. The instrument TIP (Tenerife Infrared Polarimeter) has been continuously operating since 1999 at the 70-cm German VTT of the Observatorio del Teide and has been recently moved to the 1.5-m German GREGOR. During all this time, results have been obtained concerning the nature of the weak photospheric magnetic field of the quiet sun, magneto-acoustic wave propagation, evolution with the cycle of sunspot magnetic fields, photospheric and chromospheric magnetic field in emerging regions, magnetic field in chromospheric structures such as filaments, prominences, flares, and spicules, etc. In this talk, I will review the main results obtained after all these observations and mention the main challenges for the future. With its novel polarization-free design and a complete suite of instruments aimed at simultaneous (imaging and spectroscopic) observations of the solar photosphere and chromosphere, the EST (European Solar Telescope) will represent a major world-wide infrastructure to understand the physical nature of all these phenomena.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.582-584
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• 2006

This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system compact, low-cost, and only requires a one-time calibration at the factory. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The PSD sensor is placed in the focal plane of a wide-angle lens. The micro-controller calculates the 3D position of the markers using only the measured intensity and 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system's compact size, low-cost, ease of installation, and high frame rates are suitable for high speed motion tracking in games.