Session
Technical Session II: Communications
Abstract
Tohoku University is developing a 50kg-class international scientific microsatellite named RISESAT. In addition to various scientific instruments including a 5m GSD multi-spectral high-precision Cassegrain telescope (HPT), RISESAT is also equipped with a laser communication terminal VSOTA, developed by Japanese National Institute of Information and Communications Technology (NICT) as technology demonstration mission. VSOTA stands for Very Small Optical Transmitter for Component Validation, which is a dual-band (980nm/1550nm) laser signal transmitter without gimbal mechanism or internal fine pointing mechanism. RISESAT aims to demonstrate satellite-to-ground laser communication by means of accurate attitude control of the satellite body, i.e. the direction of the laser beams fixed to the satellite structure, with an attitude control accuracy of down to 0.04 deg (3σ). Moreover, it is planned that the HPT is utilized to determine the direction of the pilot signal sent from the ground station, which can be fed back to the attitude control system for achieving higher control accuracy. The desired maximum bitrate for this mission is 1 Mbps. The NICT’s 1.5m diameter optical ground station is the primary ground station, supported by 0.3m diameter mobile optical ground stations. This is the first step toward the establishment of future optical communication infrastructures.
Presentation Slides
Laser Data Downlink System of Micro-satellite RISESAT
Tohoku University is developing a 50kg-class international scientific microsatellite named RISESAT. In addition to various scientific instruments including a 5m GSD multi-spectral high-precision Cassegrain telescope (HPT), RISESAT is also equipped with a laser communication terminal VSOTA, developed by Japanese National Institute of Information and Communications Technology (NICT) as technology demonstration mission. VSOTA stands for Very Small Optical Transmitter for Component Validation, which is a dual-band (980nm/1550nm) laser signal transmitter without gimbal mechanism or internal fine pointing mechanism. RISESAT aims to demonstrate satellite-to-ground laser communication by means of accurate attitude control of the satellite body, i.e. the direction of the laser beams fixed to the satellite structure, with an attitude control accuracy of down to 0.04 deg (3σ). Moreover, it is planned that the HPT is utilized to determine the direction of the pilot signal sent from the ground station, which can be fed back to the attitude control system for achieving higher control accuracy. The desired maximum bitrate for this mission is 1 Mbps. The NICT’s 1.5m diameter optical ground station is the primary ground station, supported by 0.3m diameter mobile optical ground stations. This is the first step toward the establishment of future optical communication infrastructures.
