For high-speed space communications, future needs of space optical communication technologies are further increasing to provide operation services of intersatellite links and direct links in the field of remote sensing and space explorations. However, cloud blockage of direct communication links is one of the issues in space optical direct communications, while the atmospheric effect on the communication links is also an important issue on the link quality in a given satellite path connected with optical ground stations. Space optical communication experiments have been performed and results have also been reported internationally, but many of them are mainly focused on communication link evaluations for stable optical direct links under atmosphere, while experiments of optical ground systems for avoidance of cloud blockage with ground network switching controls have not been sufficiently reported. For the network switching controls among optical ground stations based on cloud blockage on a given satellite path over stations, JAXA developed ground network systems. First, the laser ground network planning system is explained. Next, our optical ground stations and the infrared cloud monitoring and discrimination system for lower cloud blockage are explained. Finally, our planned network switching testings are explained.

Chapter Contents:

• 20.1 Introduction
• 20.2 Methodology
• 20.2.1 Laser ground network planning system
• 20.2.2 Optical ground stations
• 20.2.3 Infrared cloud monitoring and discrimination system
• 20.2.4 Network switching testings
• 20.3 Results
• 20.4 Conclusion
• Acknowledgments
• References

Inspec keywords: switching networks; telecommunication network planning; telecommunication control; satellite links; space communication links; optical fibre networks; optical links; satellite ground stations

Other keywords: direct communication links; remote sensing; communication link evaluations; network switching testing planning; high-speed space optical direct communication technologies; optical ground system developments; infrared cloud monitoring; intersatellite links; infrared cloud blockage monitoring; space explorations; discrimination system; optical ground stations; JAXA; optical direct link stability; laser ground network systems

Subjects: Communication network design, planning and routing; Optical fibre networks; Control applications in radio and radar; Control applications in optical communication; Space communication systems; Free-space optical links; Satellite communication systems; Communication switching