Terrestrial Free-Space Optical Communications Network for Future Airborne and Satellite-Based Optical Communications Projects

Abstract

Increased performance of onboard sensors has greatly increased the amount of communications data from satellites. The data rates from Earth observation satellites are also increasing, but communication rates of several tens of gigabits per second will inevitably be required for data download. This cannot be achieved using radio communications, but is possible using optical communications. Many demonstrations have been conducted to verify the usability of sophisticated optical communications equipment in orbit. The technology readiness level for space-based optical communications has reached seven, so the time has come to develop spacebased optical communications for use in operational environments. However, the influence of terrestrial weather conditions remains as a problem to be solved. One potential solution is site diversity, where several ground stations are used. The National Institute of Information and Communications Technology (NICT), is investigating a terrestrial free-space optical communications network for future