• Current Industrial and Technological Trends in Aerospace
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• v.7 no.1
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• pp.89-96
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• 2009

The calibration methods of satellite visible and infrared sensors for earth observations are ummarized in this paper. Commonly used instruments for the Earth observation and their calibration ethods were briefly introduced. The optical sensors (visible and infrared) and the calibration of these nstruments were focused. With the basic principles of the calibration methods, the instrument-level alibration, which are the essential calibration process for level 1 data generation, were presented.

• Bulletin of the Korean Space Science Society
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• 2008.10a
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• pp.28.3-28.3
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• 2008

Contamination has the potential for degrading the performance of the optical payload beyond the limits defined by mission requirements, therefore it must be considered a risk to system performance and must be mitigated. To mitigate contamination problem, contamination budget is allocated according to the contamination requirements which is derived from contamination effect analysis. Once the contamination budget is allocated, prediction for on-ground and in-orbit contaminants amounts and cleanliness control is performed. In this article, typical contamination control for observation satellite is described.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.178-181
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• 2004

The Tropical Rainfall Measuring Mission (TRMM) is an US-Japan joint space mission to observe tropical and subtropical rainfall. This satellite is equipped with the world's first precipitation radar that operates at 13.8 GHz. We introduce the TRMM precipitation radar (PR) system, along with the PR data processing and analysis algorithms, and some observation results obtained by the TRMM PR. It is concluded that the TRMM PR can give quite useful rainfall data for the understanding of global climate changes, meteorology, climatology, atmospheric science, and also for the studies of satellite communication.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.207-210
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• 2005

In this paper, technical issues for an optical bench of high precision LEO Earth observation satellite are described. The optical bench should be stable for thermal and dynamic environment. In this point of view, an intermediate type of optical bench is developed. Thermal deformation analysis and modal analysis are performed for two types of FE model. Modal test are performed to verify the analysis results. The test results fit well the analysis results.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.402-405
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• 2008

This paper is a proposal of Sentinel Asia for Environment (SAFE). The essential to this project is to help environmental agencies in Asia to set up an environmental monitoring system with satellite observation data. It is focused on an environmental issues originated from anthropogenic events detected as land cover and land use change in Asians' daily human life including; agriculture, global warming gas, urban environment and forest resources. It is leaded by Japan Aerospace Exploration Agency (JAXA) along with University of Tokyo and Asian Institute of Technology in Thailand under the umbrella of Sentinel Asia which is dedicated to disaster monitoring issues. It is expected to initiate a information outgoing through WWW for Asian countries to set up their national land information system focusing on environmental changes.

• Proceedings of the KSRS Conference
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• 2007.10a
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• pp.179-182
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• 2007

COMS (Communication, Ocean and Meteorological Satellite) is a geosynchronous satellite and has been developing by KARI and Astrium for Ka-band communication, ocean observation and meteorological observation. COMS Chemical Propulsion System (CPS) uses a bipropellant propulsion subsystem, which is applied for transferring COMS from GTO to GEO (mission orbit) and implementing station-keeping manoeuvres. In this paper COMS CPS is briefly introduced for understanding. A few of mathematical thermodynamic modelings of bipropellant propulsion system in literatures are reviewed and authors has studied those models for developing a computer program, which predicts variations of thermodynamic properties such as temperature and pressure histories in the helium pressurant tank, MMH propellant tank and NTO propellant tank during LAE firing and on-orbit manoeuvrings. The CPS thermodynamic model may be used to compute pressurant and propellant masses and to size tank volumes.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.11a
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• pp.747-750
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• 2004

After launching, spacecraft is exposed to extreme environments. So spacecraft should be tested after design/manufacture to verify whether components can be operated functionally. Acceleration transferred from launch vehicle to spacecraft produces quasi-static load, sine vibration and random vibration. Random vibration is also induced by acoustic vibrations transferred by surface of spacecraft. And shock vibration is produced when spacecraft is separated from launch vehicle. To verify operation of spacecraft under these launch environments, separation shock test, sine vibration test, acoustic vibration test and random vibration test should be performed. This paper describes these launch environment test requirements.

• Korean Journal of Remote Sensing
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• v.30 no.1
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• pp.13-24
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• 2014

Satellite remote sensing data have been valuable tool for volcanic ash monitoring. In this study, we present the results of application of satellite remote sensing data for monitoring of volcanic ash for three major volcanic eruption cases (2008 Chait$\acute{e}$n, 2010 Eyjafjallaj$\ddot{o}$kull, and 2011 Shinmoedake volcanoes). Volcanic ash detection products based on the Moderate Resolution Imaging Spectro-radiometer (MODIS) observation data using infrared brightness temperature difference technique were compared to the forward air mass trajectory analysis by the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. There was good correlation between MODIS volcanic ash image and trajectory lines after the volcanic eruptions, which support the feasibility of using the integration of satellite observed and model derived data for volcanic ash forecasting.

• Journal of Astronomy and Space Sciences
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• v.28 no.3
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• pp.183-192
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• 2011

The current study analyzes the effects of the scaling parameters of the batch unscented transformation on precision satellite orbit determination. Satellite laser ranging (SLR) data are used in the orbit determination algorithm, which consists of dynamics model, observation model and filtering algorithm composed of the batch unscented transformation. TOPEX/Poseidon SLR data are used by utilizing the normal point (NP) data observed from ground station. The filtering algorithm includes a repeated series of processes to determine the appropriate scaling parameters for the batch unscented transformation. To determine appropriate scaling parameters, general ranges of the scaling parameters of ${\alpha}$, ${\beta}$, k, $\lambda$ are established. Depending on the range settings, each parameter was assigned to the filtering algorithm at regular intervals. Appropriate scaling parameters are determined for observation data obtained from several observatories, by analyzing the relationship between tuning properties of the scaling parameters and estimated orbit precision. The orbit determination of satellite using the batch unscented transformation can achieve levels of accuracy within several tens of cm with the appropriate scaling parameters. The analyses in the present study give insights into the roles of scaling parameters in the batch unscented transformation method.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.641-642
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• 2013

This research implemented Geostationary Ocean Color Imager (GOCI) observation satellite imagery visualization system on a large high-resolution tiled display. This system is designed to help users observe or analyze satellite imagery more effectively on the tiled display using multi-touch and Kinect motion gesture recognition interaction. We developed the multi-scale image loading and rendering technique for the massive amount of memory management and smooth rendering for GOCI satellite imagery on the tiled display. In this system, the unit of time corresponding to the selected date of the satellite images are sequentially displayed on the screen. Users can zoom-in, zoom-out, move the imagery and select some buttons to trigger functions using both multi-touch or Kinect gesture interaction.