Overview

The IN-orbit and Networked Optical ground stations experimental Verification Advanced (INNOVA) testbed is a NICT network of optical ground stations (OGSs) spread throughout Japan. INNOVA currently consists of three OGSs: NICT Headquarters in Koganei, the Kashima Space Technology Center, and the Okinawa Electromagnetic Technology Center. The network takes advantage of cognitive diversity through site location. By keeping OGSs in different locations, INNOVA provides enough diversity to overcome uplink/downlink constraints.

Information about the link availability at each OGS is based on meteorological data, i.e., weather patterns such as cloud coverage, fog, and rain. There are ten stations located throughout Japan that collect weather data periodically and predict long-term weather patterns. The data is fed to a control center that connects the OGS network, enabling the best link to a satellite to be selected autonomously. In this way, INNOVA also uses aspects of dynamic routing. If a satellite passes into range and one OGS is covered by clouds or rain, then another OGS can be signaled for transmission.

In 2016 uplink tests during the cloudy/rainy season, each of the 3 OGSs in INNOVA had a link probability between 50 and 31%. The Okinawa and Kashima sites together had a link probability of 77%. With the Koganei site included, the INNOVA link probability was 100%. [1] Each OGS has a telescope with a 1 meter aperture, focal length of 12 meters, and LEO-tracking capabilities. The Okinawa and Kashima sites have one focusing design (Nasmyth) and the Koganei site has five focusing designs (Cassegrain, 2 different Nasmyth, and 2 different Coude).