• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.620-623
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• 2005

KARI has prepared Calibration and Validation activities for the KOMPSAT-2 (KOrea Multi-Purpose SATellite-2) MSC data that will be launched at the end of this year. Firstly, we divided the Cal/Val activities of it to four parts, Spatial, Spectral, Radiometric and Geometric, and defmed the detailed Cal/Val items from them. Secondly, Cal/Val targets have been defined and manufactured for the role of them. Thirdly, we have made the plan and the procedure for the Cal/Val items, developed the codes for them, studied more detailed method to do them, and trained the Cal/Val activities using the foreign satellite image data by ourselves. KARI has been now setting up the KOMPSAT-2 LEOP plan with the Cal/Val activities, and probably will finish the EOP Cal/Val activities for the KOMPSAT-2 MSC data by the next April or May.

• Proceedings of the KSRS Conference
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• v.1
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• pp.282-285
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• 2006

This paper analyzed the characteristics of the Lossy JPEG of the meteorological satellite image, and analyzed the quality of the Lossy JPEG compression, which is proper for the LRIT(Low Rate Information Transmission) to be serviced to the SDUS(Small-scale Data Utilization Station) system of the COMS(Communication, Oceans, Meteorological Satellite). Since COMS is to start running after 2008, we collected the data of the MTSAT-1R(Multi-functional Transport Satellite -1R) for analysis, and after forming the original image to be used to LRIT by each channel and time zone of the satellite image data, we set the different quality with the Lossy JPEG compression, and compressed the original data. For the characteristic analysis of the Lossy JPEG, we measured PSNR(Peak Signal to Noise Rate), compression rate and the time spent in compression following each quality of Lossy JPEG compression. As a result of the analysis of the satellite image data of the MTSAT-1R, the ideal quality of the Lossy JPEG compression was found to be 90% in the VIS Channel, 85% in the IR1 Channel, 80% in the IR2 Channel, 90% in the IR3 Channel and 90% in the IR4 Channel.

• ETRI Journal
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• v.24 no.3
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• pp.251-254
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• 2002

We developed a method for optimal superframe design in the multi-frequency time division multiple access (MF-TDMA) return-link of a satellite multimedia interactive network called a digital video broadcasting return channel over satellite (DVB-RCS) sub-network. To find the optimal superframe pattern with the maximum data throughput, we formulated the design problem as a non-linear combinatorial optimization problem. We also devised the proposed simple method so that it would have field applicability for improving radio resource utilization in the MF-TDMA return link.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.1258-1260
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• 2003

Cloud's properties can be showed on different spectral channel. The 0.65${\mu}$m reflectance is mainly function of cloud optical thickness and reflectance of 1.6${\mu}$m is sensitive to cloud phase and particle size distribution. So we can use multi-spectral information to analysis cloud's microphysical properties.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.2
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• pp.17-22
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• 2010

Establishment of systematic platform is needed for technological progress of receiving of satellite image data with high quality and processing system for product generation and operation related with direct receiving system for satellite from abroad. Besides, it's necessary to develop the integrated data processing system to prohibit similar functions on developing (or being developed) for KOMPSAT-3, KOMPSAT-5 and to operate system efficiently. Therefore, conceptual design of the integrated data processing system is performed considering commercialization of KOMPSAT(Korea Multi-Purpose Satellite) series based on KOMPSAT-2 IRPE on operation in this paper.

• Korean Journal of Remote Sensing
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• v.28 no.3
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• pp.329-336
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• 2012

This paper give further assessment on the original DoP-CPD classification scheme. This paper provides some additional comparative study on the DoP-CPD with H/A/alpha classifier in terms of multi look effects and classification performances. The statistics and multi looking effects of the DoP and CPD were analyzed with measured polarimetric SAR data. DoP-CPD is less sensitive to the number of averaging pixels than the entropy-alpha technique. A DoP-CPD diagram with appropriate boundaries between six different classes was then developed based on the data analysis. A polarimetric SAR image DoP-CPD classification technique is verified with C-band polarimetric RADARSAT-2 images.

• International Journal of Aeronautical and Space Sciences
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• v.1 no.2
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• pp.43-49
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• 2000

The Global Positioning System (GPS) is becoming more attractive navigation means for LEO (Low Earth Orbit) spacecraft due to the data accuracy and convenience for utilization. The anomalies such as serious variations of Dilution-Of-Precision (DOP), loss of infrequent 3-dimensional position fix, and deterioration of instantaneous accuracy of position and velocity data could be observed, which have not been appeared during the ground testing. It may cause lots of difficulty for the processing of the orbit control algorithm using the GPS data. In this paper, the characteristics of the GPS data were analyzed according to the configuration of GPS receiver such as position fix algorithm and mask angle using GPS navigation data obtained from the first Korea Multi-Purpose Satellite (KOMPSAT). The problem in orbit tracking using GPS data, including the infrequent deterioration of the accuracy, and an efficient algorithm for its countermeasures has also been introduced. The reliability and efficiency of the modified algorithm were verified by analyzing the effect of the results between algorithm simulation using KOMPSAT flight data and ground simulator.

• Journal of Astronomy and Space Sciences
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• v.35 no.3
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• pp.175-183
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• 2018

Many recent satellites have mission periods longer than 10 years; thus, satellite-based local space weather monitoring is becoming more important than ever. This article describes the instruments and data applications of the Korea Space wEather Monitor (KSEM), which is a space weather payload of the GeoKompsat-2A (GK-2A) geostationary satellite. The KSEM payload consists of energetic particle detectors, magnetometers, and a satellite charging monitor. KSEM will provide accurate measurements of the energetic particle flux and three-axis magnetic field, which are the most essential elements of space weather events, and use sensors and external data such as GOES and DSCOVR to provide five essential space weather products. The longitude of GK-2A is $128.2^{\circ}E$, while those of the GOES satellite series are $75^{\circ}W$ and $135^{\circ}W$. Multi-satellite measurements of a wide distribution of geostationary equatorial orbits by KSEM/GK-2A and other satellites will enable the development, improvement, and verification of new space weather forecasting models. KSEM employs a service-oriented magnetometer designed by ESA to reduce magnetic noise from the satellite in real time with a very short boom (1 m), which demonstrates that a satellite-based magnetometer can be made simpler and more convenient without losing any performance.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.198-203
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• 1999

Korea Multi-Purpose Satellite-1 (KOMPSAT-1) is developed by the Korea Aerospace Research Institute (KARI) with the aid of TRW and will be launched on the Nov. 24, 1999 at the Vandenberg Air Base in CA, U.S, Now, the satellite application group in KARI is preparing for the service with the KOMPSAT-1 satellite data. For the purpose of supplying good service to the users, data application planning has to be established before launching satellite. To use satellite data effectively, KARI makes a plan for data policy, data price, mission planning, and commercializing strategy. This study was carried out with the purpose of effective use of satellite data. For this purpose, KARI makes a user group first. There are 58 user groups to use KOMPSAT-1 data for public welfare and research sectors. These user groups include government, public corporations, institutes, and universities. KARI will offer the service to users through online using Internet. Secondly, KARI makes a policy for the priority of KOMPSAT-1 missions. These are classified by the mission priority, payloads, and operational states etc. Thirdly, KARI will make data policy and data price of KOMPSAT- 1 based on the basic master 1)tan. Especially, data price will be determined at trte KOMPSAT-1 committee including Ministry of Science and Technology (MOST). KARI is also trying to commercialize the data with the domestic and foreign companies to expand the use of KOMPSAT-1 data in the industries sector. Afterward in this study, KARI will continue the improvement for the effective distribution of KOMPSAT-1 data for all users.

• Proceedings of the KSRS Conference
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• v.2
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• pp.791-793
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• 2006

In the satellite camera, the incoming light source is converted to electronic analog signals by the electronic component for example CCD (Charge Coupled Device) detectors. The analog signals are amplified, biased and converted into digital signals (pixel data stream) in the video processor (A/Ds). The outputs of the A/Ds are digitally multiplexed and driven out using differential line drivers (two pairs of wires) for cross strap requirement. The MSC (Multi-Spectral Camera) in the KOMPSAT-2 which is a LEO spacecraft will be used to generate observation imagery data in two main channels. The MSC is to obtain data for high-resolution images by converting incoming light from the earth into digital stream of pixel data. The video data outputs are then MUXd, converted to 8 bit bytes, serialized and transmitted to the NUC (Non-Uniformity Correction) module by the Hotlink data transmitter. In this paper, the video data streams, the video data format, and the image data processing routine for satellite camera are described in terms of satellite camera control hardware. The advanced satellite with very high resolution requires faster and more complex image data chain than this algorithm. So, the effective change of the used image data chain and the fast video data transmission method are discussed in this paper