NICT is developing the HICALI (High Speed Communication with Advanced Laser Instrument) payload and an optical ground station to demonstrate 10 Gbps-class optical satellite communication between geostationary orbit and the ground. The HICALI payload is planned to be mounted on the Engineering Test Satellite-9 (ETS-9) which will be launched in 2023. In this paper, we present the status of the HICALI payload and optical ground station development and discuss the initial experiment results using a star (Betelgeus), a planet (Venus) and low-Earth orbit satellite-to-ground optical links.
Laser communication is an expected approach to realize a high data rate communication on small, micro and even cube satellites. Sony and Japan Aerospace Exploration Agency (JAXA) had experimentally verified fundamental functions of the small optical communication terminal with optical disk technology that is needed for miniaturization of light-weight and low power consumption laser communication terminals. To verify these functions from the optical disk technology in orbit as a laser communication system, Sony Computer Science Laboratories, Inc. (Sony CSL) and JAXA had jointly developed the small optical communication terminal called SOLISS from late 2017 that designed to be attached to the exposed facility of International Space Station (ISS) and it was successfully launched from Tanegashima in Japan on 25th September 2019. This experimentation aims to confirm 100 Mbps Ethernet-based laser communication establishment between low-Earth orbit and the ground and the availability of pointing control with the optical disk technology in-orbit. To achieve the goal, SOLISS continuously controls the accurate pointing with a coarse and fine pointing mechanism to keep the establishment of the optical link with a counterpart. In this experimentation, SOLISS successfully established the bidirectional Ethernet-based link with a PC connected to the optical ground station of National Institute of Information and Communications Technology (NICT) by its pointing mechanism. The result demonstrated the availability of the proposed pointing mechanism. This article discusses the pointing performance of SOLISS with the optical ground station.
SOLISS is designed for technology demonstration of small laser communication terminal connecting to optical ground station from International Space Station (ISS) and its name came from Small Optical Link for ISS. It was successfully launched on 25th Sep., 2019 and achieved to demonstrate bi-directional communication as its extra success. SOLISS is jointly developed with Japan Aerospace Exploration Agency (JAXA) and also jointly developed special functions of optical ground station with National Institute of Information and Communications Technology (NICT). We discuss and report in-orbit demonstration and its result.
Recent technology trends of cost reduction of launch and satellite miniaturization are leading cutting-edge applications such as earth observation and communication with satellite constellation. Miniaturization of the communication terminal, light weight and low power consumption are required to the communication terminal on small satellites. Free space optical communication is expected approach to realize high data rate communication system on small satellites. Sony and Japan Aerospace Exploration Agency (JAXA) have experimentally verified the fundamental functions of the small optical communication terminal with optical disk technology for small satellites since 2016. Following this basic study, Sony Computer Science Laboratories, Inc. (Sony CSL) has jointly studied in orbit experiment of the small optical communication terminal with JAXA. To verify its functions in-orbit promptly, we have tried to utilize IVA-replaceable Small Exposed Experiment Platform(i-SEEP) attached to Japanese Experiment Module (JEM) on International Space Station (ISS). The developed small optical communication terminal (SOLISS) is connected to i-SEEP and SOLISS is designed to verify bi-directional communication with free-space optical technology capable of 100 Mbps Ethernet frame data transfer between SOLISS and the optical ground station. For the optical ground station connecting with SOLISS, Sony CSL also conducts a joint research project with National Institute of Information and Communications Technology (NICT). To establish the optical communication link, telemetry and commanding through ISS, controlling of the optical ground station and SOLISS are designed. This article discusses the system architecture for in-orbit experimentation of bi-directional optical communication between SOLISS and the optical ground station.
In National Institute of Information and Communications Technology (NICT) of JAPAN, an ultra high speed optical satellite communication equipment onboard the engineering test satellite IX has been developing. The satellite is planned to be launched to geosynchronous orbit in 2021. In this project, we are aiming for ultra high-speed data transmission at the world's highest level of 10 [Gbps] for both uplink and downlink between optical ground stations and geosynchronous satellite. This paper outlines the optical communication mission, the scheduled optical communication experiment, the examination of HICALI and the ground based system at the present time - the outline of the development situation is also explained.
Recently, satellite broadband communication services using Ka-band are emerging all over the world, some requiring capacities in excess of 100 Gbps. With the radio bandwidth resources becoming exhausted, high-speed optical communications can be used instead to achieve ultra-broadband communications. The National Institute of Information and Communications Technology (NICT) in Japan has over 20 years of experience in R&D of space laser communications with missions such as the Engineering Test Satellite VI (ETS-VI), OICETS, and SOCRATES/SOTA. We are currently developing a laser communication terminal named “HICALI”, aiming to achieve 10 Gbps-class space communications with a 1.5 μm-band laser beam between optical ground stations (OGSs) and the next generation high throughout satellite called ETS-IX with a hybrid communication system using radio and optical frequencies, which will be launched into the geostationary orbit in 2021. Moreover, we have studied laser communication terminals for terrestrial networks, as an alternative wireless system to radio frequency (RF) band. In 2014, we developed a terrestrial free-space optical communications network facility, named INNOVA (IN-orbit and Networked Optical ground stations experimental Verification Advanced testbed). Many demonstrations have been conducted to verify the feasibility of sophisticated optical communications equipment in orbit.
We have conducted a feasibility study of a laser communication terminal for next-generation space networks following the above R&D trends in space communication networks, which is a high-speed, secure, small, and scalable laser communication terminal for optical ground stations (OGSs) and satellites or airborne terminals. In this paper, we describe the plan of NICT to develop a scalable laser communication terminal for next-generation space networks.
In recent years, the necessity of satellite-to-ground optical communication has increased as a method for realizing higher-speed communications between satellites and the ground. However, one disadvantage of free-space optical (FSO) communication is the significant influence of the atmosphere. FSO communications cannot be utilized under certain atmospheric conditions, such as cloudy skies. One of the solutions to this problem is site diversity, which makes it possible to select a given ground station with better atmospheric conditions among a number of fixed ground stations. The other solution is to prepare a ground station that can be moved to a place with better atmospheric conditions. In this paper, we present the development of a transportable optical ground station currently being researched in NICT.
In order to be transportable, it is necessary to build a system capable of travelling on public roads, installable in every place, and ready to be loaded on relatively-light trucks. For this purpose, a realistic telescope diameter is about 30 cm at the maximum, capable of being set up quickly, and with a pointing accuracy of about 100 μrad. In addition, it is necessary to prepare a fine-pointing optical system that performs tracking with about 1/10 of the pointing accuracy of the telescope. In this research, we will develop the base of the transportable optical ground station using the knowledge of mobile astronomical telescopes. With respect to tracking, we will develop a smaller and lighter fine-tracking system based on NICT’s previous experience. If necessary, we plan to develop an adaptive-optics system for correcting atmospheric disturbances to improve the fiber-coupling efficiency of the communication laser beam.
Research and development of a novel method for a secure free-space optical communication system has been done in NICT since 2018, and demonstration experiments between an aircraft and a transportable optical ground station are planned in near future. In order to establish a stable and highly accurate optical communication link, the system must have a fine pointing mechanism in both the aircraft and the ground station. A compact and light-weight tracking system is required to be mounted on the aircraft, and there will be needed to have an adjustment function of the beam divergence control to allow stable communication under various altitude and atmospheric conditions. The transportable optical ground station should maintain vibration resistance when moving, and it must be easily deployed on each site where is the appropriate optical ground station site with respect to atmospheric turbulence condition.
Recently, satellite broadband communication services using Ka-band are emerging all over the world, some of them with capacities in excess of 100 Gbps. However, as the radio bandwidth resources become exhausted, high-speed optical communication can be used instead to achieve ultra-broadband communications. The National Institute of Information and Communications Technology (NICT) in Japan has more than 20 years of experience in R&D of space laser communications, with important milestones like ETS-VI (Engineering Test Satellite VI), OICETS, and SOTA. We are currently developing a laser-communication terminal called “HICALI”, which goal is to achieve 10 Gbps-class space communications in the 1.5-μm band between Optical Ground Stations (OGSs) and a next generation high-throughput satellite (called ETS-IX) with a hybrid communication system using radio and optical frequencies, which will be launched into a geostationary orbit in 2021. The development of test and a breadboard model for HICALI has been conducted for several years and we are now carrying out an engineering model as well as designing the OGSs segment. In this paper, we describe concepts and current design status of the HICALI system.
In recent years, the performance of observation equipment mounted on satellites has improved to such levels that it can obtain significant amount of data from a single observation [1]. Radio waves are used as a method for transmitting large volumes of data acquired by satellites to the ground. However, currently operational radio frequencies make it difficult to improve the communication speed, owing to interference problems and the carrier frequency. Space optical communication is expected to be a solution to this problem.
Optical Satellite Downlinks have gathered increasing attention in the last years. A number of experimental payloads have become available, and downlink experiments are conducted around the globe. One of these experimental systems is SOTA, the Small Optical Transponder, built by the National Institute of Information and Communications Technology (NICT).
This paper describes the downlink experiments carried out from SOTA to the German Aerospace Center’s Optical Ground Stations located in Oberpfaffenhofen, Germany. Both the Transportable Optical Ground Station (TOGS) as well as the fixed Optical Ground Station Oberpfaffenhofen (OGS-OP) are used for the experiments. This paper will explain the preparatory work, the execution of the campaign, as well as show the first results of the measurements.
Recently, the sensors ability of remote sensing satellites are offering much better resolution, higher quality, etc. [1] The gathered data size by the satellite has become larger. However, generally, downlink transfer capacity from the satellite to a ground station using RF (Radio Frequency) communication is limited, due to the internal balance of resources (power consumption, size capacity, mass, placement, etc.) in the satellite, and allocation of bandwidth by frequency regulation arrangement.
In collaboration between CNES, NICT, Geoazur, the first successful lasercom link between the micro-satellite SOCRATES and an OGS in Europe has been established. This paper presents some results of telecom and scintillation first data analysis for 4 successful links in June & July 2015 between SOTA terminal and MEO optical ground station (OGS) at Caussols France. The telecom and scintillation data have been continuously recorded during the passes by using a detector developed at the laboratory. An irradiance of 190 nW/m2 and 430 nW/m2 has been detected for 1549 nm and 976 nm downlinks at 35° elevation. Spectrums of power fluctuation measured at OGS are analyzed at different elevation angles and at different diameters of telescope aperture to determine fluctuations caused by pointing error (due to satellite & OGS telescope vibrations) and caused by atmospheric turbulence. Downlink & Uplink budgets are analyzed, the theoretical estimation matches well to measured power levels. Telecom signal forms and bit error rates (BER) of 1549 nm and 976 nm downlink are also shown at different diameters of telescope aperture. BER is 'Error Free' with full-aperture 1.5m telescope, and almost in ‘good channel’ with 0.4 m sub-aperture of telescope. We also show the comparison between the expected and measured BER distributions.
Research and development of space optical communications is conducted in the National Institute of Information and Communications Technology (NICT). The NICT developed the Small Optical TrAnsponder (SOTA), which was embarked on a 50kg-class satellite and launched into a low earth orbit (LEO). The space-to-ground laser communication experiments have been conducted with the SOTA. Atmospheric turbulence causes signal fadings and becomes an issue to be solved in satellite-to-ground laser communication links. Therefore, as error-correcting functions, a Reed-Solomon (RS) code and a Low-Density Generator Matrix (LDGM) code are implemented in the communication system onboard the SOTA. In this paper, we present the in-orbit verification results of SOTA including the characteristic of the functions, the communication performance with the LDGM code via satellite-to-ground atmospheric paths, and the link budget analysis and the comparison between theoretical and experimental results.
KEYWORDS: Optical communications, Free space optical communications, Optical networks, Data communications, Satellites, Free space optics, Satellite communications, Telecommunications, Data centers, Control systems
A terrestrial free-space optical communications network facility, named IN-orbit and Networked Optical ground stations
experimental Verification Advanced testbed (INNOVA) is introduced. Many demonstrations have been conducted to
verify the usability of sophisticated optical communications equipment in orbit. However, the influence of terrestrial
weather conditions remains as an issue to be solved. One potential solution is site diversity, where several ground
stations are used. In such systems, implementing direct high-speed optical communications links for transmission of data
from satellites to terrestrial sites requires that links can be established even in the presence of clouds and rain. NICT is
developing a terrestrial free-space optical communications network called INNOVA for future airborne and satellitebased
optical communications projects. Several ground stations and environmental monitoring stations around Japan are
being used to explore the site diversity concept. This paper describes the terrestrial free-space optical communications
network facility, the monitoring stations around Japan for free-space laser communications, and potential research at
NICT.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.