• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.1
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• pp.1-9
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• 2004

Until comparatively lately the use of vector data is the main current in GIS fields. Vector data have many advantages such as easy of scale change, small data volume and so on. But it also has some weak point that can't apply real world. The other hand the satellite images have strong point that can apply real world actually. Recently rapid progress of computer capacity and processing velocity is the current trend of the times. Therefore in this study I intend to develop GIS application based on satellite images with vector data and raster data altogether. This system is developed by using Visual C＋＋ in the personal computer and MS Access's MDB far database management. The LANDSAT, KOMPSAT and IKONOS satellite image database were used in this study. Also, we are studied to set up scale for screen display according to spatial resolution.

• Journal of Satellite, Information and Communications
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• v.11 no.3
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• pp.72-79
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• 2016

In this paper, we propose a Service-adaptive Tactical Data Transmission Protocol (STTS) based on Satellite Communications with narrow bandwidth. STTS is designed to provide additional field for scalability and scheduler for reliability of transport stream protocol based on digital broadcasting standard, DVB-S and DVB-S2. It is also verified the effects of lost data packets with narrow bandwidth through the simulator by traffic model and re-transmission of critical data, and checked the design considerations based on STTS system.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.8-10
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• 2012

위성을 전체적으로 제어하는 탑재소프트웨어가 동작하는 주 메모리와는 별도로 세이프가드 메모리가 있다. 세이프가드 메모리는 주로 위성의 장애관리를 위해 사용되는 것으로 프로세서 리셋 시에 전체적으로 초기화가 수행되는 주 메모리와는 달리 별도의 전원을 사용하여 항상 Power-ON 상태를 유지하고 주/부 2개의 메모리가 주/부 프로세서와 Cross-Strap으로 연결되어 어느 프로세서에서든 접속이 가능하도록 구성되어 있다. 위성에 심각한 장애가 발생하여 정상적인 운영이 불가능한 경우, 위성은 Fail-over 과정을 거치게 되는데, Fail-over 과정에서 2개의 세이프가드 메모리의 비상운영데이터 영역에 장애 발생원인 및 프로세서 리셋 이후에 필요한 정보들을 기록하고, 미리 정해진 Backup 하드웨어를 이용하여 시스템 초기화가 수행된다. Backup 하드웨어를 통하여 프로세서가 정상적으로 Boot-up되면 세이프가드 메모리에 저장된 비상운영데이터를 이용하여 위성의 장애발생 원인을 파악하고, 정상운영모드로 복귀하는 절차를 거치게 된다. 본 논문은 저궤도 위성에서 사용되는 세이프가드 메모리 운영방식에 대해 기술한 것이다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.5
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• pp.417-424
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• 2021

The S-band telemetry and telecommand formats for geostationary orbit satellites should have sufficient reliability, since they transmit massive satellite health data and receive the mission commands in the 36,000km of the geostationary orbit. Also, they have to efficiently manage the large quantity of satellite health data under the limited data transmission rate. Cheollian-2A and 2B satellites were developed by Korea Aerospace Research Institute and launched at 2018 and 2020, respectively. Their missions are to conduct continuously the mission of Cheollian-1, which was the first geostationary orbit satellite of Korea. Therefore, the fundamental S-band data format design for Cheollian-2A and 2B should meet the requirements of Cheollian-1. Meanwhile the latest remote data processing techniques for these newest geostationary orbit satellites should be implemented. In this paper, the advanced S-band space data formats and management methods are proposed for more efficient data transmission, reception and operation with the limited data rate of the geostationary orbit satellites. The implemented results in the flight software of Cheollian-2A and 2B are described in detail.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.4
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• pp.347-352
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• 2007

This paper describes the design and implementation of PFM(Proto Flight Model, PFM) of DRE(Data Receiving Equipment, DRE) for Science and Technology Satellite 2(STSAT-2) and the results of integration performance test. DRE components are X-band receiver, DCE(Data Combine Equipment, DCE) and RAC(Receiving and Archiving Computer, RAC). DCE consists of I&Q data combiner and ECL signal distributor. RAC consists of DRC(Data Receiving Card) and ST2RAS(STSAT-2 Receiving and Archinving Software). X-band receiver receives 10Mbps QPSK I, Q satellite data and sends the data to DCE. DRC stores the I&Q combine data from DCE to RAID. The pre-processing program sorts and stores to satellite status data and payload data. The performance of DRE in the functional and space environments test satisfies the requirements of STSAT-2.

• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.1
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• pp.62-77
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• 2019

Open Data Cube(ODC) has been emerging and developing as the open source platform in the Committee on Earth Observation Satellites(CEOS) for the Global Earth Observation System of Systems(GEOSS) deployed by the Group on Earth Observations (GEO), ODC can be applied to the deployment of scalable and large amounts of free and open satellite images in a cloud computing environment, and ODC-based country or regional application services have been provided for public users on the high performance. This study first summarizes the status of ODC, and then presents concepts and some considering points for linking this platform with Korea Multi-Purpose Satellite (KOMPSAT) images. For the reference, the main contents of ODC with the Google Earth Engine(GEE) were compared. Application procedures of KOMPSAT satellite image to implement ODC service were explained, and an intermediate process related to data ingestion using actual data was demonstrated. As well, it suggested some practical schemes to utilize KOMPSAT satellite images for the ODC application service from the perspective of open data licensing. Policy and technical products for KOMPSAT images to ODC are expected to provide important references for GEOSS in GEO to apply new satellite images of other countries and organizations in the future.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.335-335
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• 2007

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.65.1-65.1
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• 2015

근지구 우주환경 예측을 위해서는 태양의 주기, 흑점, 그리고 코로나의 방출과 함께 Van Allen Belt에 붙잡힌 고에너지 입자의 상태 변화가 우주 환경의 예보를 위한 중요 요소가 된다. 이런 고에너지 입자를 측정하기 위해서는 Van Allen Belt를 통과하는 VAP 위성의 데이터를 살펴보는 것이 매우 중요하다. 이 연구에서는 한국천문연구원에서 APL과 공동으로 VAP 위성의 실시간 데이터를 송수신하는 시스템을 구축하고, 그 실시간 데이터를 우주환경감시실에서 표출하여 Van Allen Belt의 변화를 바로 알아보는 과정을 기술 하였다. 이를 통해 데이터의 경향성을 바로 파악하여 특정 이벤트의 발생을 알아 낼 수 있을 뿐만아니라 과거의 데이터를 손쉽게 찾아볼 수 있었다. 별도의 프로그램을 개발하여 데이터의 표출 비교를 가능하게 함으로써 다른 위성의 데이터나 태양 이미지를 보지 않아도 자체 비교를 통해 이벤트의 발생을 찾아 볼 수 있게 되었다.

• Journal of Navigation and Port Research
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• v.42 no.1
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• pp.17-24
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• 2018

The Russian Global Navigation Satellite System (GLONASS) has been fully recovered since October 2011, and it has been significantly modernized. The recently launched GLONASS 752 was set for successful performance on October 16, 2017 and has resulted in 24-satellite constellation with 22 second-generation (GLONASS-M) satellites, and a third-generation (GLONASS-K) satellite. Therefore, this paper is focused on not only the identified navigation parameters, but also the performance analysis of the project based on its real data received from the studied satellites. It is verified that the 5-11 satellites are available for receiving navigation signal at this time. The obtained values of GDOP, PDOP, HDOP, VDOP, and TDOP are 2.790, 2.424, 1.169, 2.123, and 1.381, noted respectively in standard deviation. In fact, the level of positioning precision is about 1.4m in standard deviation. As a result, the positioning performances of the measured GLONASS and GPS are virtually identical. Therefore, we determine that the GLONASS is expected to be expanded for future applications.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.11
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• pp.61-69
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• 2006

Position determination accuracy is strongly depending on how much precisely and frequently satellite receiver measures transmitted signals from terminals on target animals when Doppler effect is applied for position determination. ARGOS satellite system has shown relatively high position determination accuracy by operating multiple satellites, which enable operator to get more Doppler shift data from terminals. In case of animal tracking mission with single satellite, however, it is difficult for the satellite receiver to receive transmitted signals from terminals frequently during short period that satellite passes over ground terminals. This is one of the main sources to decrease position accuracy on target animals. In this paper, the Doppler rate estimation is implemented to increase the number of Doppler shift data received by single satellite. It is proved that the relatively high position determination accuracy with increased number of estimated data can be obtained. We also suggest that the Doppler rate estimation is applicable for position determination system with single satellite.