Recent Japanese R&D in Satellite Communications

Abstract

SUMMARYCurrent trend in telecommunications is "broadband" and "ubiquitous." To achieve this goal, satellite communications systems are expected to play an important role in cooperation with terrestrial communications systems. Along with the advancement of optical fiber transmission systems, the role of satellite communications was dramatically changed from long distance transmission to various applications utilizing unique features of satellite communications. This paper overviews recent Japanese R&D in satellite communications.

Meteorological satellite stakeholder relationship network based on social network analysis

“…From the ego network, the local network, and the overall network, the measure-ment principle of different network features is clarified, and the evaluation index system for the coordination degree of the relational network is formed to complete a comprehensive evaluation design. SNA involves combining a graph with a matrix and ◎Weather live report ◎Maritime satellite system ◎Weather channel 9 Cheng X N [33] ◎Meteorological public service ◎Weather forecast ◎Mass media ◎TV viewer ◎Netizen Zhang Q S, et al [34] ◎WeChat public account ◎The public ◎Flood control and drought relief command department Carr R H, et al [35] ◎National Weather Service(NWS) ◎National Oceanic and Atmospheric Administration(NOAA) ◎The public ◎Forecast and early warning products Yuan H L, et al [36] ◎The public ◎New media ◎Public weather service ◎Primary industry ◎NWS Lin R H, et al [37] ◎Meteorological film and television ◎The public ◎TV media ◎Three dimensional rural issues Chattopadhyay N, et al [38] ◎Competent meteorological satellite department ◎Meteorological technology ◎Agricultural sector ◎Agricultural Meteorological Consulting ◎Farmer Umehira M, et al [39] ◎Korea Communications Commission ◎Ministry of Education, Science, and Technology ◎Satellite communications department ◎SMEs and the private sector ◎University Bayissa Y, et al [40] ◎Drought early warning system ◎Assessing the spatial and temporal pattern of drought ◎School…”

QoS provisioning by power control for video communication via satellite links

“…WINDS was launched by the Japan Aerospace Exploration Agency and the National Institute of Information and Communications Technology in February 2008. WINDS aims to develop technologies for ultrahigh data rate satellite communications in the Ka-band [20]. The USAT with a two-reflector antenna is an earth station developed for easy deployment and installation in inaccessible areas for communication purposes.…”

Background light reduction method with a double phase conjugate mirror and a phase plate for optical inter-satellite communications

“…Laser satellite communications whose operating frequency is much higher than that of radio frequency systems have been intensively studied to increase transmission speed and data capacity. [1][2][3][4][5][6][7] It can provide many attractive advantages such as high-speed transmission with high confidence, no electromagnetic interference, and low power consumption. These are due to greater bandwidth and smaller divergence angle of laser beams with much higher directivity than radio frequency.…”