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Satellite control service

Utilization of high value-added satellite information to improve public safety and quality of life.

Use of satellite information

From land management to disaster monitoring

KARI is currently controlling and operating the Arirang and Cheollian satellites, which are national satellite assets; it plans to manage and utilize systematically the integrated national satellite information to prepare for the multi-satellite era. The Institute is in charge of record planning, receiving, processing, and distributing images for the Arirang and Cheollian satellites; it is planning research and development to promote satellite image processing and utilization. Satellite images have recently been used as important big data that create high added value in the 4th Industrial Revolution era. KARI promotes the use of satellite images acquired from various satellites, including the world's best high-level resolution imaging satellites. The Arirang generates about 100,000 satellite images per year, including sub-meter high-resolution satellite images, radar images, and infrared images provided to the public and private sectors. The Cheollian continuously generates satellite images for meteorological, ocean, and environmental observations. These satellite images are crucial in various fields such as land management, disaster monitoring, marine water resource management, agricultural and forestry applications, environmental weather observation, national security, industrial activities, and daily life.

Integrated satellite operation and efficient use of satellite information

KARI operates the National Satellite Information Utilization Support Center, a national organization for national satellites' integrated operation and promotion of systematic, efficient satellite information utilization. The National Satellite Information Utilization Support Center plays the role of enhancing the support and utilization system based on the private demand for satellite information to promote the use of various kinds of satellite information acquired by satellites, promoting the industries using satellite information and use services, and constructing the infrastructure for the satellite information utilization industry. The Center has formed the Satellite Information Utilization Council to supply satellite images to 31 government agencies to satisfy public demand according to the national mid- to long-term space development policy. Moreover, the Center builds the national satellite information integration database and platform so that the public and private sectors can readily use the national satellite data and enhance the added value of national satellite data to access satellite data easily.

Satellite Information Utilization Council

KARI performs four major tasks through the operation of the council. First, it acquires and processes the satellite information required by the government council and produces and distributes standard and high value-added images. It also constructs and operates the information management system by acquiring Korean Peninsula images recorded by foreign satellites such as PeruSat-1. KARI has constructed a platform dedicated to using satellite information for the council by systematically implementing and enhancing the council operation support system and developing the order management system for the systematic management of the council's satellite information. Moreover, it operates the additional processing system it has implemented to produce high value-added information. It also operates the large-capacity database management system it has developed for the stable management of high value-added satellite information. KARI plans to develop commercialization technology for satellite information to help the council collaborating institutions utilize satellite information efficiently. It intends to secure technology that can analyze urban changes, forest damage, and farming land changes to support field service organizations. Moreover, it is developing tools to support the council users in checking and processing images.Lastly, it has organized a specialized group for each council's division to operate the council and provide user education. It is also holding use seminars and providing users' technical education to support the council's field service. Moreover, it holds workshops on utilizing satellite information and annual meetings to share satellite information utilization technology and know-how.

Satellite control service

Updates : 2021.06.25

Satellite orbit/altitude control and real-time operation

KARI implemented Korea’s first ground station operation system to control Arirang 1 and independently developed a ground station system for the Cheollian. It controls seven national satellites: Arirang 2, 3, 5, and 3A and Cheollian 1, 2A, and 2B. KARI has planned research to automate multi-satellite control and operation such as low-orbit and geostationary-orbit satellites; it is researching the application of AI to satellite status monitoring and problem detection. The ground station operation system for satellite control mainly consists of a control system and a reception processing system. The control system performs remote tracking and command, satellite operation, and mission analysis for satellites in space. The system consists of a ground transmission/reception system with large antennas, RF module, and modem/BB, a satellite control system to perform satellite status monitoring and command, position/altitude adjustment, and mission planning, and an image pre-processing system for radiometry and geometric compensation and broadcast distribution data generation. The reception processing system downloads the image data recorded by satellites and processes them.

Satellite control maximization by operating antennas in overseas ground stations

KARI is constructing ground station antennas in Korea and other countries to maximize satellite control by expanding satellites and ground stations' communication domain. As the demand for the Korean Peninsula and overseas images filmed by the Arirang has increased, the satellite is continuously increasing the image recording. KARI is installing and operating antennas at ground stations in Korea and other countries to acquire images quickly after recording. It operates two antennas to control and receive low-orbit satellites and three antennas for controlling and receiving geostationary orbit satellites in its Daejeon headquarters. It constructed a 13-meter antenna system to operate Arirang 1, Korea’s first earth observation satellite launched in 1999. It also constructed a 7-meter antenna system to meet the requirement for an antenna independent from the existing 13-meter one following the launch of more satellites. It is used as the main control and reception antenna system for Arirang 5, an all-weather imaging radar satellite. In 2004, KARI constructed a small 1.5-meter antenna at the Sejong Station in Antarctica to control low orbital satellites and a small 2.4-meter antenna at the South Pacific Science Station in Micronesia in 2014 to control low and geostationary orbital satellites. Moreover, it is operating an antenna at the Svalbard Ground Station in Norway under a contract with the Norwegian KSAT (Kongsberg Satellite) and the German Space Agency to maintain the command transmission system of the Arirang and control the satellite when necessary, such as satellite safety mode, emergency operation, and mission change. In 2017, it constructed a VPN in Neustrelitz, Germany for overseas reception facilities and implemented a real-time satellite control and video reception and transmission system. KARI downloads the images recorded by satellites through the satellite antenna at the Daejeon headquarters and in Svalbard, Norway and checks the satellite status with the antenna at the Sejong Station in Antarctica and Micronesia.

In-house development of ground system diagram for geostationary orbital satellites

KARI internally developed a ground system to control Cheollian 1 and Cheollian 2A and 2B and receive images. The ground system consists of a ground transmission/reception system with large antennas, RF module, and modem/BB, a satellite control system to perform satellite status monitoring and command, position/altitude adjustment, and mission planning, and an image pre-processing system for radiometry and geometric compensation and broadcast distribution data generation. The ground system for Cheollian 1 consists of a ground transmission/reception system with an antenna having a diameter of 13 meters, a satellite control system, and a weather/marine image pre-processing system. The ground system for Cheollian 2A and 2B consists of an antenna, each having a ground transmission/reception system with diameter of 9 meters, a satellite control system, and a weather/marine image pre-processing system.

Operation of safe satellites by monitoring space objects

KARI monitors collision 24 hours a day using the integrated management system of space debris collision risk and the automation tool to monitor space objects approaching the national satellites. In 2014, KARI developed KARISMA (KAri space debris collision RISk MAnagement System), Korea’s first software to analyze and respond to the risk of collision with space debris. The system operates the Arirang and Cheollian satellites safely by protecting them from potential collisions with space debris. KARISMA can calculate the probability of Korea’s satellites colliding with a space object (including other satellites and space debris) and analyze the approaching distance to plan a collision avoidance operation using the orbit information of space objects with diameter of 10cm or more as disclosed by the US JSpOC (Joint Space Operations Center). When the collision probability is higher than 1 in 1,000, the collision avoidance operation moves the satellite in a direction that reduces the risk of collision with minimal fuel using an optimal algorithm that considers variables such as the error range for each approach direction and the relative collision speed. KARISMA features the user-friendly analysis of collision risk, automation, 3D analysis, various optimal collision avoidance plans, and interface with existing aerodynamics systems. KARI plans to install a precision image radar to analyze the possibility of a Korean satellite colliding with an artificial space object with diameter of 10 centimeters or larger and an optical surveillance telescope in 2023, according to the “National Basic Plan for Space Risk Preparation” established in May 2014. Once the space object surveillance and tracking radar system is put in place in Korea, Korean satellites' collision risk can be quickly analyzed for a response.

Main mission of satellite control

  • (Aerodynamics) Satellite orbit prediction and calculation
  • (Mission plan) Establishment of a plan for camera operation timing, altitude, and communication status
  • (Real-time operation) Control of the normal execution of missions according to commands
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