• Korean Journal of Remote Sensing
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• v.37 no.1
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• pp.169-176
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• 2021

The Global Space-based Inter-Calibration System (GSICS) is an international partnership sponsored by World Meteorological Organization (WMO) to continue and improve climate monitoring and to ensure consistent accuracy between observation data from meteorological satellites operating around the world. The objective for GSICS is to inter-calibration from pairs of satellites observations, which includes direct comparison of collocated Geostationary Earth Orbit (GEO)-Low Earth Orbit (LEO) observations. One of the GSICS inter-calibration methods, the Ray-matching technique, is a surrogate approach that uses matched, co-angled and co-located pixels to transfer the calibration from a well calibrated satellite sensor to another sensor. In Korea, the first GEO satellite, Communication Ocean and Meteorological Satellite (COMS), is used to participate in the GSICS program. The National Meteorological Satellite Center (NMSC), which operated COMS/MI, calculated the Radiative Transfer Model (RTM)-based GSICS coefficient coefficients. The L1P reproduced through GSICS correction coefficient showed lower RMSE and Bias than L1B without GSICS correction coefficient applied. The calculation cycles of the GSICS correction coefficients for COMS/MI visible channel are provided annual and diurnal (2, 5, 10, 14-day), but long-term evaluation according to these cycles was not performed. The purpose of this paper is to perform evaluation depending on the annual/diurnal cycles of COMS/MI GSICS correction coefficients based on the ray-matching technique using Suomi-NPP/Visible Infrared Imaging Radiometer Suite (VIIRS) data as reference data. As a result of evaluation, the diurnal cycle had a higher coincidence rate with the reference data than the annual cycle, and the 14-day diurnal cycle was the most suitable for use as the GSICS correction coefficient.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1278-1280
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• 2003

Striping is a main factor for imaging spectroradiometer data, which is obtained by multi-sensor scanning on spacecraft. The reason causing stripes and the development of striping removal methods are simply described in this paper, particularly, the principle of Matching Empirical Distribution Functions is introduced in detail. By using this method, some experiments are done to destripe imaging spectrometer data of SZ-3. The result shows that the method of Matching Empirical Distribution Functions is available for destirping Imaging spectroradiometer data of SZ-3, and the quality of image is improved obviously. This will help to process the future similar instruments data.

• Korean Journal of Remote Sensing
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• v.16 no.4
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• pp.347-353
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• 2000

The purpose of this paper is to extract DEM (Digital Elevation Model) using KOMPSAT images. DEM extraction consists of three parts. First part is the modeling of satellite position and attitude, second part is the matching of two images to find corresponding points of them and third part is to calculate the elevation of each point by using the result of the first and second part. The position and attitude modeling of satellite is processed by using GCPs. Area based matching method is used to find the corresponding points between the stereo satellite images. The elevation of each point is calculated using the exterior orientation information obtained from sensor modeling and the disparity from the stereo matching. In experiment, the KOMPSAT images, 2592$\times$2796 panchromatic images are used to extract DEM. The experiment result show the DEM using KOMPSAT images.

• Korean Journal of Geomatics
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• v.4 no.1
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• pp.31-37
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• 2004

The aim of this research is comparing the existing approximation models (e.g. Affine Transformation and Direct Linear Transformation) with Rational Function Model as a substitute of rigorous sensor model of linear array scanner, especially push-broom sensor. To do so, this research investigates the mathematical model of each approximation method. This is followed by the assessments of accuracy of transformation from object space to image space by using simulated data generated by collinearity equations which incorporate or depict the physical aspects of linear array sensor.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.6
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• pp.2546-2566
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• 2016

This paper investigates an efficient transmission scheme for the remote wireless sensors to receive information which is rarely discussed in the integrated remote wireless sensor and multibeam satellite networks (IWSMSNs). The networks can be employed to exchange sensing information for emergency scenario, ocean scenario, and so on, which are isolated from available terrestrial networks. As the efficient transmission link is important to the IWSMSNs, we propose a hybrid full frequency (HFF) precoding by taking advantage of frequency reuse and multiple-input multiple-output (MIMO) precoding. Considering energy efficiency and sinks fairness are crucial to transmission link, thus the HFF precoding problems are formulated as transmit power minimization (TPM) and max-min fair (MMF) received signal to interference plus noise ratio (SINR) problems, which can be transformed to indefinite quadratic optimization programs. Then this paper presents a semi-definite programming (SDP) algorithm to solve the problems for the IWSMSNs. The promising potential of HFF for the real IWSMSNs is demonstrated through simulations.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.37 no.6
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• pp.517-523
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• 2019

PM₁₀ concentration is a spatiotemporal phenomenta and capturing data for such continuous phenomena is a difficult task. This study designed a model that enhances spatiotemporal resolution of PM₁₀ concentration levels using satellite imagery, atmospheric and meteorological sensor data, and multiple deep learning models. The designed deep learning model was trained using input data whose factors may affect concentration of PM₁₀ such as meteorological conditions and land-use. Using this model, PM₁₀ images having 15 minute temporal resolution and 30m×30m spatial resolution were produced with only atmospheric and meteorological data.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.29 no.2
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• pp.157-164
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• 2011

As high-resolution satellite images have enabled large scale topographic mapping and monitoring on global scale with short revisit time, agile sensor orientation, and large swath width, many countries make effort to secure the satellite image information. In Korea, KOMPSAT-2 (KOrea Multi-Purpose SATellite-2) was launched in July 28 2006 with high specification. These satellites have stereo image acquisition capability for 3D mapping and monitoring. To efficiently handle stereo images such as stereo display and monitoring, the accurate epipolar image generation process is prerequisite. However, the process was highly limited due to complexity in epipolar geometry of pushbroom sensor. Recently, the piecewise approach to generate epipolar images using RPC was developed and tested for in-track IKONOS stereo images. In this paper, the piecewise approach was tested for KOMPSAT-2 across-track stereo images to see how accurately KOMPSAT-2 epipolar images can be generated for 3D geospatial applications. In the experiment, two across-track stereo sets from three KOMPSAT-2 images of different dates were tested using RPC as the sensor model. The test results showed that one-pixel level of y-parallax was achieved for manually measured tie points.

• Korean Journal of Remote Sensing
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• v.36 no.4
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• pp.645-652
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• 2020

GK2A(GEO-KOMPSAT-2A)satellite has been operating excellently since its launch in Dec 2018. The secondary payload called KSEM (Korean Space Environment Monitor) was equipped into the GK2A satellite along with AMI (Advanced Meteorological Imager) sensor. KSEM is the Korea's first operational geostationary space weather sensor and has been developed collaboratively by KHU (Kyung Hee University) and KARI (Korea Aerospace Research Institute). The interface works between KSEM and GK2A were conducted by KARI. Various interface tests, which aim for evaluating effective functionality of KSEM with the spacecraft, were intensively conducted at KARI facilities. Main tests consisted of mechanical and electrical check-up activities between the KSEM and GK2A. Interface tests of KSEM, which involve pre-launch tests such as ETB and GK2A system level tests, were conducted to evaluate functional and performance of KSEM before the launch. The tests carried out during the GK2A LEOP (Launch and Early Orbit Phase) and IOT (In Orbit Test) period (Dec 2018 ~ June 2019) showed excellent in-orbit performance of KSEM data.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.2
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• pp.50-67
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• 2000

The spacecraft simulator is used for command validation, operational check of the Satellite Operation Subsystem (SOS), spacecraft anomaly analysis support, satellite operator training etc. In this paper, S/W design features and modeling characteristics of the KOMPSAT Spacecraft Simulator Subsystem (SIM) are described. Validation procedures and simulation results are also provided. The SIM provides extensive simulation capabilities by including models for most of the spacecraft subsystems. The software structure of the SIM was designed and implemented so as to support operations not only in real-time but also in non real-time by utilizing the Hewlett Packard (HP) UNIX functions. The SIM incorporates as many user-friendly Man Machine Interface (MMI) windows as possible so that all the SIM normal operations can be executed through the MMI windows.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 1996.06b
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• pp.1-6
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• 1996

To promote academic researches on earth environment utilizing satellite data, research infrastructure such as satellite data reception processing, distribution and archival systems should be fully provided. The means to enhance the infrastructure were discussed by a working group and“Satellite Data Center via Network”has been proposed. This concept has three principles; (1) To realize necessary functions by organizing experts distributed all over Japan and connecting them by network, (2) To realize“Satellite Data Center via Network”for GMS and NOAA Satellites, which are widely used for research, and (3) Satellite data set oriented to specific research area should be generated by researchers having definite research purposes of sensor algorithms and hugh volume data processing. Utilization of the Science Information Network (SINET) has been discussed to realize this concept, and to accelerate this project an experiment“Network Utilization for Wide Area Use of Satellite Image Data”under“Cooperative Experiment on Multimedia Communication”has been introduced. And the roles of the Institute of Industrial Science, University of Tokyo to contribute this project has been described.