Behind the Scenes: GISTDA’s Satellite Operations for Earth Observation

   Satellite data is now integral to various national interests, from high-resolution imaging for urban planning and natural resource management to providing crucial information for disaster response. The use of space-based data is increasingly vital.

   GISTDA, or the Geo-Informatics and Space Technology Development Agency (Public Organization), currently operates two high-resolution Earth observation satellites in orbit: THEOS-1 (Thaichote) and THEOS-2. There are also plans for future satellite launches to expand Thailand's Earth observation satellite constellation, enhancing the effective use of space data for government agencies and the public.

   To efficiently manage these assets, GISTDA established the Satellite Operation Office, Thailand's sole mission control center for Earth observation satellites. This center is staffed by experienced Thai engineers and space technologists who command and control the satellites, and receive their signals, ensuring timely support for national missions.

   The daily process of satellite imaging begins with receiving user requests specifying the desired area for photography and assessing the feasibility of the task. The team then collaborates on mission planning, which includes prioritizing tasks, forecasting cloud cover globally, and calculating the operational plan. Mr. Boonchoob Boongthong, Director of the Satellite Operation Office, explains, "We typically categorize requests into three priority levels. The highest urgency is for disasters, security matters, or government directives that directly impact the public, which we must capture within 1-3 days."

   "The next level is 'urgent,' which involves monitoring less severe disasters or assessing post-event damage, for which we have pre-planned monitoring over specific areas. This category also includes paying customers. The final group is 'general,' which involves routine imaging as the satellite passes over various regions in Thailand and worldwide. This data is archived to track future changes."

   Once all information is processed and the imaging plan is confirmed, satellite control engineers transmit commands to the satellites via GISTDA's ground station at the Space Inspirium in Sriracha, Chonburi.

   When a satellite comes within the 2,500-kilometer contact radius of the ground station, the operations team sends new imaging commands using the S-band frequency. Simultaneously, they monitor the satellite's status and check the health of its various systems. The station also receives imagery data transmitted from the satellite on the X-band frequency, which is then processed into satellite images.

   Regarding the satellite's daily workload, Mr. Boonchoob states, "Each day, the satellite images over 100 areas according to the established plan. After the plan is uploaded, the satellite processes it and activates its camera when passing over the target locations, storing the data in its memory to be downlinked during its next pass near a ground station."

   While the satellites orbit over Thailand, GISTDA engineers are on duty to receive signals from THEOS-1, THEOS-2, and partner agency satellites. Upon receiving the signal, the data undergoes a process to convert it into a digital format. This includes geometric correction to align the image with the Earth's surface and radiometric correction to fix any signal discrepancies, ensuring the final image data meets established standards.

   Beyond mission-specific imaging, Mr. Boonchoob reveals that the satellites require regular calibration. "To ensure the quality of the data we see, the satellite must capture images of the sea at night, specifically in areas with minimal light from Earth during a new moon, to detect any white spots on the camera's sensor. We also command it to photograph deserts during the day to measure sensor quality, which is then used to fine-tune the camera for maximum accuracy."

   However, satellite control involves more than just taking pictures from space. It also entails maintaining the satellite's operational readiness. This includes monitoring space traffic in conjunction with the ZIRCON system, developed by GISTDA's Space Technology Research Center, to adjust the satellite's trajectory for optimal and efficient mission performance. The team must also troubleshoot issues, such as when a satellite enters 'Safe Mode' due to system malfunctions or solar storms. Thai engineers are responsible for monitoring and systematically checking to resolve these errors and restore the satellite to normal operations as quickly as possible.

   Finally, for young people interested in a career in satellite operations like the staff at GISTDA, the Director of the Satellite Operation Office offers this advice: "We have many different sections. The operating system relies on fundamental computer knowledge, a foundation that many Thai youth already have and can build upon. If you're interested in data calibration, a background in physics and Earth science is crucial. For those wanting to work in satellite control and communication, skills in wireless communication, such as a degree in telecommunications or electrical engineering, are very important."

   "Furthermore, for processing satellite imagery, those who have studied geography and geo-informatics will have a strong foundation to build on. For understanding satellite orbits, mechatronics engineering graduates can learn quickly. There are also roles in data-archive management, system maintenance, and many other areas where people can learn and grow. As you can see, satellite technology requires a diverse range of skills, presenting a great opportunity for interested students."

   It is clear that the Satellite Operation Office is a crucial behind-the-scenes team for Thailand's space operations, enabling the use of images and data from space for various benefits. It stands as a point of pride for the Thai people, showcasing the nation's skilled personnel and comprehensive infrastructure for exploring and utilizing space data for the maximum benefit of the country.