• Aerospace Engineering and Technology
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• v.12 no.2
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• pp.91-98
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• 2013

Computing environment of space explorer including LEO (Low Earth Orbit), GEO (Geosynchronous Earth Orbit) satellite may be considered as the same category of embedded system on the ground. But with comparison with personal computing environment it is widely accepted that the space computing is outdated and behind of state of the art. Especially file system which is nearly essential item in all ground computing environment including personal computer, workstation and server is rarely used in space explorer till lately. In this paper, a study of ESA PUS (Packet Utilization Standard) and CCSDS (Consultative Committee for Space Data Systems) community's activity, international trend, and applicable technical application for applying file system in oder to use these standards for utilizing the file system to deep space explorer is described.

• Current Industrial and Technological Trends in Aerospace
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• v.6 no.2
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• pp.90-98
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• 2008

In recent, image data compression method of high resolution satellite image is the important issue for its application and development. The CCSDS (Consultative Committee for Space Data Systems) published a standard for the high resolution image data compression, CCSDS 122.0-B-1, in the end of 2005, which is expected to be widely applied in process of compression for the high resolution satellite images. In this paper, it is explained that the current trends of image compression methods for high resolution satellites, and then the comparison results between CCSDS 122.0-B-1 standard and JPEG are described.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.4
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• pp.295-301
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• 2020

When a spacecraft in deep space falls into an abnormal state, an emergency communication channel between ground and the spacecraft is essential in order to perform analysis to the cause of the anomaly, and to remedy the spacecraft from the distressed state. Because the recovery actions generally comprises of long and complicated sequences of commands, the transmission of the recovery commands may require a reliable and a delay tolerant networking technology based on bundle routing. While the delay tolerant networking protocol becomes a prominent method interfacing ground and space into a internet-like Solar system network because it can address the issues of the severe communication problems in deep space, the communication system on the spacecraft which based on space packet protocol cannot use the delay tolerant networking technology directly. So a community of the consultative committee for space data systems starts a discussion of the first-hop last-hop mechanism to establish a feasible concept and standardization. This paper presents an enhanced concept of the first-hop last-hop by applying it a virtual cislunar communication environment, and we believe this contributes to make a way applicable to an interoperable relay concept of the first hop last hop between the delay tolerant networking and space packet protocol standard.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.1
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• pp.42-49
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• 2011

Telemetry link requires high data rate to transmit the multimedia data for lunar explorations in space communications. In this paper, we analyze a data rate with the modulation and channel coding schemes based on Consultative Committee for Space Data Systems (CCSDS) in S, X, Ku and Ka bands, respectively. Then, we suggests modulation and channel coding schemes to meet the link margins and have a maximum data rate for lunar explorations in telemetry links.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.662-664
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• 1998

본 논문에서는 다목적 실용위성인 아리랑위성(KOMPSAT-I)에서 지상과의통신을 위해 사용하는 CCSDS(Consultative Committee for Space Data Systems)표준 Command/Telemetry(CMD/TLM)시스템과 KOMPSAT-I의 목적에 맞게 이를 적용한 CMD/TLM 시스템을 소개한다. 현재 한국항공우주 연구소는 Observer 회원 자격으로 CCSDS 에 가입되어 있으며 국내 위성 개발에서 CMD/TLM 시스템에 CCSDS프로토콜을 사용한 것은 처음이다.

• Journal of Astronomy and Space Sciences
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• v.27 no.1
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• pp.11-20
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• 2010

This paper designs a data link between a Lunar Orbiter (LO) and an Earth Station (ES), and analyzes the downlink performance of a space communications system for lunar exploration, conforming to the recommendations by the Consultative Committee for Space Data Systems (CCSDS). The results provided in the paper can be useful references for the design of reliable communication link for the Korean lunar exploration in the near future.

• Journal of Astronomy and Space Sciences
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• v.27 no.2
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• pp.129-134
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• 2010

Rain attenuation can cause a serious problem that an availability of space communication link on Ka band becomes low. To reduce the effect of rain attenuation on the error performance of space communications in Ka band, an adaptive coding and modulation (ACM) scheme is required. In this paper, to achieve a reliable telemetry data transmission, we propose an adaptive coding and modulation level using turbo code recommended by the consultative committee for space data systems (CCSDS) and various modulation methods (QPSK, 8PSK, 4+12 APSK, and 4+12+16 APSK) adopted in the digital video broadcasting-satellite2 (DVB-S2).

• Journal of Astronomy and Space Sciences
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• v.27 no.3
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• pp.221-230
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• 2010

A 4+12+16 amplitude phase shift keying (APSK) modulation outperforms other 32-APSK modulations in a nonlinear additive white Gaussian noise (AWGN) channel because of its intrinsic robustness against AM/AM and AM/PM distortions caused by the nonlinear characteristics of a high-power amplifier. Thus, this modulation scheme has been adopted in the digital video broadcasting-satellite2 European standard. And it has been considered for high rate transmission of telemetry data on deep space communications in consultative committee for space data systems which provides a forum for discussion of common problems in the development and operation of space data systems. In this paper, we present an improved bits-to-symbol mapping scheme with a better bit error rate for a 4+12+16 APSK signal in a nonlinear AWGN channel and propose a simple signal detection algorithm for the 4+12+16 APSK from the presented bit mapping.

• Journal of Space Technology and Applications
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• v.2 no.2
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• pp.137-145
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• 2022

Space development has been independently performed by space agencies in each country. This causes redundant development for individual function, resulting in waste of space resources. Accordingly, Interagency Operations Advisory Group (IOAG) was established for standardization with mutual agreement between international organizations, and space resources can be used efficiently between space agencies through cross-support. IOAG define Service Catalog#1, #2, and #3, according to the network layer. In this technical paper, the background and main contents of the IOAG Service Catalog, and the application plan for domestic space development will be discussed.

• ETRI Journal
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• v.22 no.1
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• pp.1-11
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• 2000

The Satellite Operation System (SOS) has been developed for a low earth orbiting remote sensing satellite, Korea Multipurpose Satellite-I, to monitor and control the spacecraft as well as to perform the mission operation. SOS was designed to operate on UNIX in the HP workstations. In the design of SOS, flexibility, reliability, expandability and interoperability were the main objectives. In order to achieve these objectives, a CASE tool, a database management system, consultative committee for space data systems recommendation, and a real-time distributed processing middle-ware have been integrated into the system. A database driven structure was adopted as the baseline architecture for a generic machine-independent, mission specific database. Also a logical address based inter-process communication scheme was introduced for a distributed allocation of the network resources. Specifically, a hotstandby redundancy scheme was highlighted in the design seeking for higher system reliability and uninterrupted service required in a real-time fashion during the satellite passes. Through various tests, SOS had been verified its functional, performance, and inter-face requirements. Design, implementation, and testing of the SOS for KOMPSAT-I is presented in this paper.