The application of optical communications technology for intersatellite and direct links is increasing in the fields of remote sensing and space explorations. Optical communication experiments have been conducted internationally and there are plans to use related technologies for space operations. However, there are not many experiments or plans for the network of optical ground stations focused on the particular issue of how to avoid cloud blocking in optical links between space and the ground for effective data downlink. In 2015, JAXA reported on a future experimental plan for optical direct communication links from space to ground in order to acquire the fundamental technologies of spatial pointing and tracking with the International Space Station and the experimental concept for the avoidance of cloud blockings by optical ground stations, cloud sensors and network planning systems [3]. To forward the study on flexible optical ground network operations, JAXA began joint research with Tokai University in 2017 and has studied more specific experiment method with ground fiber networks, cloud sensors, network planning systems and meteorological satellite data. This paper presents the research and development approach to realize flexible optical ground network operations for effective data downlink from space to ground.

Inspec keywords: space communication links; satellite links; optical fibre networks; telecommunication network planning; optical links

Other keywords: remote sensing; network planning systems; optical direct communication links; Tokai University; optical ground stations; flexible optical ground network operations; data downlink; space exploration operations; optical communications technology; cloud sensors; ground fiber networks; JAXA; International Space Station

Subjects: Optical fibre networks; Free-space optical links; Satellite communication systems; Communication network design, planning and routing; Space communication systems