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No.466 OCT 2017 Optical Satellite Communication toward the Future of Ultra High-speed Wireless Communications No.466 OCT 2017 National Institute of Information and Communications Technology CONTENTS FEATURE Optical Satellite Communication toward the Future of Ultra High-speed Wireless Communications 1 INTERVIEW New Possibilities Demonstrated by Micro-satellites Morio TOYOSHIMA 4 A Deep-space Optical Communication and Ranging Application Single photon detector and receiver for observation of space debris Hiroo KUNIMORI 6 Environmental-data Collection System for Satellite-to-Ground Optical Communications Verification of the site diversity effect Kenji SUZUKI 8 Optical Observation System for Satellites Using Optical Telescopes Supporting safe satellite operation and satellite communication experiment Tetsuharu FUSE 10 Development of "HICALI" Ultra-high-speed optical satellite communication between a geosynchronous satellite and the ground Toshihiro KUBO-OKA TOPICS 12 NICT Intellectual Property -Series 6- Live Electrooptic Imaging (LEI) Camera —Real-time visual comprehension of invisible electromagnetic waves— 13 Awards 13 Development of the “STARDUST” Cyber-attack Enticement Platform Cover photo Optical telescope with 1 m primary mirror. It receives data by collecting light from sat- ellites. This was the main telescope used in experiments with the Small Optical TrAn- sponder (SOTA). This optical telescope has three focal planes, a Cassegrain, a Nasmyth, and a coudé. The photo in the upper left of this page shows SOTA mounted in a 50 kg-class micro- satellite. In a world-leading effort, this was developed to conduct basic research on technology for 1.5-micron band optical communication between low-earth-orbit sat- ellite and the ground and to test satellite-mounted equipment in a space environment. Recent basic experiments in quantum communication have also been successful, as published in Nature Photonics. The telescope has a diameter of approximately 5 cm, and the mass of SOTA is approximately 6 kg. Optical Satellite Communication toward the Future of Ultra High-speed Wireless Communications Interview New Possibilities Demonstrated by Micro-satellites High precision Earth observation satel- Relay System (JDRS) using an optical data re- lites are being launched, one after another. lay satellite. These are micro-satellites of many types, used for research, education, and commer- ─How is research organized and what are cial purposes. As the development of space the main research themes in the Space Com- becomes more familiar in our daily lives, it munications Laboratory? is bringing a range of new conveniences. The Space Communications Laboratory, TOYOSHIMA: The laboratory has two locations, Wireless Networks Research Center, con- our headquarters in Koganei and the Kashima ducts R&D, focusing on optical (laser) sat- Space Technology Center, with approximately ellite communications, in hopes of making 50 members conducting research and devel- breakthroughs in satellite communications opment, including researchers, students, and data transmission technology. We spoke to supporting staff. Our two main research themes Laboratory Director, Dr. Morio TOYOSHIMA, are radio satellite communications and optical about this research. satellite communications. Our objectives are to establish satellite communications using these to develop communication networks that can be ■ "Mega-constellations" advancing in used at sea and in space, and be useful in mo- Morio TOYOSHIMA many countries Director bile situations and for disaster prevention and Space Communications Laboratory ─ To begin with, can you tell us about cur- mitigation. Wireless Networks Research Center rent trends in space communications tech- In several countries, recently so-called Joined the Communications Research Lab- nology? High-Throughput Satellite (HTS) services are oratory, Ministry of Posts and Telecommu- being started using Ka band communications nications (currently NICT), in 1994. After engaging in ETS-VI laser communication TOYOSHIMA: Many countries have been work- satellites with capacity exceeding 100 Gbps. experiments, Morio TOYOSHIMA was trans- ing actively on mega-constellation projects* in However, HTS services are limited by the com- ferred to NASDA (currently JAXA), and after recent years. This development of space itself munications capacity of gateways called feed- doing research at Vienna University of Tech- nology, worked on the research and devel- holds potential for innovation, and several of er links, connecting the earth station and the opment of onboard laser communication these projects are considering use of optical sat- satellite, that bundle user lines with terrestrial equipment for OICETS, SOTA, and HICALI, ellite communications. communications, and technology to expand the was involved in satellite laser communica- tion and quantum key distribution (QKD) A recent trend particularly in optical satel- feeder link communications capacity is highly experiments. Ph. D (Engineering). lite communications is the planned implemen- sought after. Our laboratory is conducting R&D tation of optical data relay satellite systems in on genuine multi-gigabit optical satellite com- the United States, Europe, and Japan. NASA's munications technology to resolve this issue Lunar Laser Communication Demonstration and establish infrastructure technologies for 10 (LLCD) at the Goddard Space Flight Center Gbps-class optical communications to resolve (GSFC) successfully established 622 Mbps op- demand for high-capacity next generation com- tical communication links between the moon munications. and the earth using a satellite launched in September 2013. And in April 2019, NASA's ■ Extra success achieved by the SOTA Laser Communication Relay Demonstration project (LCRD) project plans to launch an optical data relay satellite system into geostationary orbits. ─ Is the Small Optical TrAnsponder In Europe, the European Space Agency (ESA) (SOTA) project completed at the end of last operates an optical data relay service on geosta- year part of these efforts? tionary satellites called the European Data Re- lay System (EDRS), and the Copernicus Earth ＊ Groups of many small satellites or unmanned aircraft are observation project has launched five low-earth linked and cooperate to achieve a specific objective. As orbit (LEO) Sentinel satellites that initiate op- with constellations of stars and orbital positions, groups of satellites in particular are called satellite constellations. tical communications for data transmission. In There are many projects, largely promoted by Google (USA) Japan, the Japan Aerospace Exploration Agen- and Facebook (USA), being executed by companies includ- ing Space-X (USA), Oneweb (USA), O3b (UK), Leosat (USA), cy (JAXA) is also planning the Japanese Data and Kaskilo (formerly eightyLEO, Germany). NICT NEWS OCT 2017 1 Optical Satellite Communication toward the Future of Ultra High-speed Wireless Communications Interview New Possibilities Demonstrated by Micro-satellites TOYOSHIMA: The goal of the SOTA project was to expand optical satellite communications technology for very small satellites, developing 6 kg-class ultra-compact optical communica- tions equipment (Small Optical TrAnsponder, SOTA), and to demonstrate it mounted on the 50 kg-class Space Optical Communications Research Advanced Technology Satellite (SOCRATES). It was done in collaboration with private enterprise. The project started in 2009, and after the preliminary design review and the critical design review, a flight model was built. The SOCRATES satellite carrying SOTA was launched into low-earth orbit in May 2014. In the demonstration, images taken by an onboard camera mounted on the 50-kg class micro-sat- ellite were transmitted via optical communica- tions for the first time, using 1.5-micron laser light with original error correcting codes im- plemented in SOTA. The low-earth orbit made it accessible from various countries during its orbit, therefore international collaboration tests using SOTA were also conducted, involving international space agencies such as CNES in France, DLR in Germany, CSA in Canada, and the ESA in Europe. In particular, we conducted successful adaptive optics (AO) experiments SOTA installed in a micro-satellite. Telescope diameter is approximately 5 cm, using SOTA with the CNES optical ground and the mass is approximately 6 kg. station. In optical satellite communications ex- periments, telescope operation and commu- nication tests were done mainly by Expert Maki AKIOKA, Senior Researcher Yoshisada international collaboration experiments. This the low mass and resultant low inertial moment KOYAMA, Researcher Yasushi MUNEMASA, work yielded more success than expected. make it difficult to stabilize. No one had done and Researcher Hideki TAKENAKA. In- such a test and there was no past data, so there ternational collaborative experiments were ─ Can you tell us about some of the diffi- was an element of trial-and-error in the design planned and performed by Researcher Dimitar culties and innovations encountered in the work. KOLEV, and polarized light measurement ex- SOTA project? We also had issues with materials. In space, periments were done by Researcher Alberto thermally-resistant materials are an important CARRASCO-CASADO, and Researcher TOYOSHIMA: Earlier successes used satellites factor. Any deformation can result in inabil- Hideki TAKENAKA. as large as several hundred kilograms, so at ity to communicate properly. In space, metals These experiments
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