• Title, Summary, Keyword: LRIT

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LRIT DESIGN OF COMS

  • KOO In-Hoi;PARK Durk-Jong;SEO Seok-Bae;AHN Sang-Il;KIM Eun-Kyou
    • Proceedings of the KSRS Conference
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    • pp.305-308
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    • 2005
  • The COMS, Korea's first geostationary multipurpose satellite program will accommodate 3 kind of payloads; Ka-Band communication transponder, GOCI (Geostationary Ocean Color Imager), and MI (Meteorological Imager). MI raw data will be transferred to ground station via L-band link. The ground station will perform image data processing for raw data, generate them into the LRIT/HRIT format, the user dissemination data recommended by the CGMS. The LRIT/HRIT are disseminated via satellite to user stations. This paper shows the COMS LRIT data generation procedure based on COMS LRIT specification and its verification results using the LRIT user station.

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COMPARISON OF SUB-SAMPLING ALGORITHM FOR LRIT IMAGE GENERATION

  • Bae, Hee-Jin;Ahn, Sang-Il
    • Proceedings of the KSRS Conference
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    • pp.109-113
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    • 2007
  • The COMS provides the LRIT/HRIT services to users. The COMS LRIT/HRIT broadcast service should satisfy the 15 minutes timeliness requirement. The requirement is important and critical enough to impact overall performance of the LHGS. HRIT image data is acquired from INRSM output receiving but LRIT image data is generated by sub-sampling HRIT image data in the LHGS. Specially, since LRIT is acquired from sub-sampled HRIT image data, LRIT processing spent more time. Besides, some of data loss for LRIT occurs since LRIT is compressed by lossy JPEG. Therefore, algorithm with the fastest processing speed and simplicity to be implemented should be selected to satisfy the requirement. Investigated sub-sampling algorithm for the LHGS were nearest neighbour algorithm, bilinear algorithm and bicubic algorithm. Nearest neighbour algorithm is selected for COMS LHGS considering the speed, simplicity and anti-aliasing corresponding to the guideline of user (KMA: Korea Meteorological Administration) to maintain the most cloud itself information in a view of meteorology. But the nearest neighbour algorithm is known as the worst performance. Therefore, it is studied in this paper that the selection of nearest neighbour algorithm for the LHGS is reasonable. First of all, characteristic of 3 sub-sampling algorithms is studied and compared. Then, several sub-sampling algorithm were applied to MTSAT-1R image data corresponding to COMS HRIT. Also, resized image was acquired from sub-sampled image with the identical sub-sampling algorithms applied to sub-sampling from HRIT to LRIT. And the difference between original image and resized image is compared. Besides, PSNR and MSE are calculated for each algorithm. This paper shows that it is appropriate to select nearest neighbour algorithm for COMS LHGS since sub-sampled image by nearest neighbour algorithm is little difference with that of other algorithms in quality performance from PSNR.

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JPEG Compression Pereformance Analysis of MTSAT-1R HRIT_LRIT

  • Kim, Tae-Young;Kim, Tae-Hoon;Ahn, Sang-Il;SaKong, Young-Bo
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.463-468
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    • 2006
  • This paper analyzed the JPEG compression performance of MTSAT-lR (Multi-functional Transport Satellite-1 Replacement), which is offering the LRIT/HRIT (Low Rate Information Transmissio/High Rate Information Transmission) service now, in order to design the system regarding LRIT/HRIT of COMS (Communication, Ocean and Meteorological Satellite). To do so, we analysed Lossy and Lossless JPEG compression performance regarding the MTSAT-1R LRIT/HRIT data for 10 days, and made comparison to the image characteristics, and understood the JPEG compression characteristics regarding JPEG compression of geostationary meteorological satellite. This result of compression performance analysis is expected to be a reference not only to the system design and realization of COMS LRIT/HRIT but also to those who develop other meteorological satellite receiving systems.

MTSAT-1R HRIT/LRIT Quality Analysis (MTSAT-1R HRIT/LRIT 품질 분석)

  • Jeon Bong-Ki;Kim Tae-Hoon;SaKong Young-Bo;Ahn Sang-Il
    • Proceedings of the KSRS Conference
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    • pp.394-397
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    • 2006
  • 본 논문에서는 일본의 정지궤도 위성인 MTSAT(Multi-functional Transport Satellite)-1R의 HRIT/LRIT(High Rate Information Transmission/Low Rate Information Transmission) 데이터의 특성 및 오차를 분석하였다. HRIT/LRIT 데이터를 수신하여 영상을 추출하고, 추출한 영상에 ITU(International Telecommunication Union)의 Space Radiocommunications Stations(이하 SDS) CD에 있는 Map 데이터를 겹쳐서 실제 해안선과의 차이를 계산하였다. 분석을 위하여 10일간의 HRIT/LRIT 수신 데이터를 사용하였고 분석한 결과 MTSAT-1R 위성의 HRIT VIS 영상의 평균오차는 Line 4.42 Pixel, Column 0.66 Pixel, LRIT IR1 영상의 평균오차는 Line 1.05 Pixel, Column 0.19 Pixel인 것을 알 수 있었다.

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JPEG COMPRESSION PERFORMANCE ANALYSIS OF MTSAT-1R HRIT_LRIT

  • Kim, Tae-Young;Kim, Tae-Hoon;Ahn, Sang-Il;Sa Kong, Young-Bo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.286-289
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    • 2006
  • This paper analyzed the JPEG compression performance of MTSAT-1R(Multi-functional Transport Satellite - 1 Replacement), which is offering the LRIT/HRIT(Low Rate Information Transmissio / High Rate Information Transmission) service now, in order to design the system regarding LRIT/HRIT of COMS(Communication, Ocean and Meteorological Satellite). To do so, we analysed Lossy and Lossless JPEG compression performance regarding the MTSAT-1R LRIT/HRIT data for 10 days, and made comparison to the image characteristics, and understood the JPEG compression characteristics regarding JPEG compression of geostationary meteorological satellite. This result of compression performance analysis is expected to be a reference not only to the system design and realization of COMS LRIT/HRIT but also to those who develop other meteorological satellite receiving systems.

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International Trends on Vessel Identification and Tracking and E- Navigation Strategy (선박식별 및 추적장치의 국제동향과 전자항해전략에 관한 연구)

  • Jeong Jung-Sik;Nam Taek-Kun;Kim Chul-Seung;Park Sung-Hyeon;Yim Jeong-Bin;Ahn Young-Sup
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • pp.105-111
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    • 2006
  • In the IMO COMSAR 10th meeting, the SOLAS performance standard draft for Long-range Identification and Tracking(LRIT) was submitted to MSC. '81 meeting for its approval. The LRIT and AIS would provide an important data in monitoring SOLAS vessels at shore. This paper aims to suggest the vision and future directions for a successful E-navigation development in co-orporation with vessel monitoring.

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COMS DATS Implementation and Test (통신해양기상위성 데이터 송수신 서브시스템의 구축 및 시험)

  • Park, Durk-Jong;Kim, Su-Jin;Ahn, Sang-Il
    • Journal of Astronomy and Space Sciences
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    • v.25 no.4
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    • pp.459-470
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    • 2008
  • DATS which is one of three subsystems of IDACS is responsible to receive Sensor Data, LRIT and HRIT in L-Band and transmit LRIT and HRIT in S-Band from/to COMS satellite. This paper shows detailed test procedures used to verify the performance and functionality of DATS after its implementation was completely finished. As a part of efforts to verify key DATS performance, G/T and EIRP were measured by using solar flux density as radio source. Regarding the verification of DATS functionality, RF loop-back test was conducted to validate if there is no BER degradation excepting MODEM/BB implementation loss occurred in the integrated DATS. Integrated with 13m antenna, DATS successfully restored image from received MTSAT-1R broadcasting data, LRIT and HRIT, of which frequencies are all L-Band. S-Band transmission was also verified through test antenna placed away from 13m antenna by measuring real LRIT and HRIT spectrum in S-Band. From those test results, DATS is determined to be fully ready to communicate with COMS in L-Band and S-Band.

JPEG Performance analysis for COMS LHGS Design (통신해양 기상위성 LHGS 설계를 위한 JPEG 성능 분석)

  • Bae Hee-Jin;Seo Seok-Bae;Ahn Sang-Il;Jung Sung-Chul;Kim Eun-Kyou
    • Proceedings of the KSRS Conference
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    • pp.381-385
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    • 2006
  • 2008년 발사를 목표로 개발되고 있는 통신해양기상위성(COMS: Communication, Ocean and Meteorological Satellite)는 기상 관측과 해양 관측 임무 및 통신 임무까지 수행하는 정지궤도 위성이다. 통신해양기상위성은 크게 탑재체와 지상국으로 나눌 수 있고 지상국은 다시 통신 임무를 위한 CTES(Communication Test Earth Station), 해양/기상 임무를 위한 IDACS(Image Acquisition and Control System), 그리고 위성 관제와 운영을 위한 SGCS(Satellite Ground Control System)로 구분된다. 이 중 IDACS의 서브시스템 중 하나인 LHGS(LRIT/HRIT Generation Subsystem)는 LRIT/HRIT(Low Rate Information Transmission/High Rate Information Transmission)를 생성하고 배포하는 기능을 가지고 있다. 관측 종료 후 LRIT/HRIT 전송 완료까지 15분 이내로 이루어져야 한다는 기상청의 요구사항을 만족하기 위해서 JPEG 압축 시간도 중요한 요소로 고려되어야 한다. 그래서 본 논문에서는 MTSAT에서 받은 LRIT/HRIT의 자료 처리를 바탕으로 lossless JPEG와 lossy JPEG의 압축 시간을 측정하여 압축률을 비교하여 성능 분석을 해보기로 한다. 이렇게 도출해낸 수치자료는 COMS LHGS 설계에 활용할 수 있다.

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An Analysis of Data Transmission Rate of HRIT/LRIT for COMS (통신해양기상위성의 HRIT/LRIT 데이터 전송률 분석)

  • Jung Sung-Chul;Seo Seok-Bae;Ahn Sang-Il;Baek Seon-Kyun
    • Proceedings of the KSRS Conference
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    • pp.398-403
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    • 2006
  • 2008년 발사를 목표로 개발되고 있는 통신해양기상위성(COMS : Communication, Ocean and Meteorological Satellite)의 기상 탑재체를 이용한 기상 관측 임무는 기상청 기상위성센터(가칭)의 고유 임무로서, 이는 기상탑재체에서 관측한 자료를 수신 처리하여 고품질의 영상과 분석 자료를 생산하여 기상 예보 업무에 활용하고, 위성을 통하여 국내외 사용자들에게 분배하는 것 등을 포함한다. 위성을 통한 기상 자료 서비스는 국내에서는 최초로 시도되는 것으로, 국제기상위성운영 기관들의 모임인 기상위성조정그룹회의(CGMS Coordination Group for Meteorological Satellites)에서 권고하는 High Rate Information Transmission/Low Rate Information Transmission(HRIT/LRIT)라는 특정 자료 형태를 사용하여 분배하게 된다. 따라서 본 논문에서는 CGMS에서 권고하는 CCSDS (Consultative Committee for Space Data Systems) 전송 규격과 일본의 MTSAT-1R(Multi-functional Transport Satellite) 위성 사용자 서비스 자료 형태를 참고하여 통신해양기상위성의 효과적인 기상자료 분배를 위한 HRIT/LRIT 데이터 전송률을 분석하여 보았다.

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Development of FPGA-based Meteorological Information Data Receiver Circuit for Low-Cost Meteorological Information Receiver System for COMS (보급형 천리안 위성 기상정보 수신시스템을 위한 FPGA 기반 기상정보 데이터 수신회로 개발)

  • Ryu, Sang-Moon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.10
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    • pp.2373-2379
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    • 2015
  • COMS(Communication, Ocean and Meteorological Satellite), the first Korean geostationary meteorological satellite, provides free meteorological information through HRIT/LRIT(High/Low Rate Information Transmission) service. This work presents the development of data receiver circuit that is essential to the implementation of a low-cost meteorological information receiver system. The data receiver circuit processes the data units according to the specification of physical layer and data link layer of HRIT/LRIT service. For this purpose, the circuit consists of a Viterbi decoder, a sync. word detector, a derandomizer, a Reed-Solomon decoder and so on. The circuit also supports PCI express interface to pass the information data on to the host PC. The circuit was implemented on an FPGA(field programmable gate array) and its function was verified through simulations and hardware implementation.