한국항공우주연구원

First Release of the Ocean Color Images of the Seas around the Korean Peninsula taken by Cheollian 2B
- Successful reception of the first ocean color images from Cheollian 2B! -

□ The Ministry of Science and ICT (MSIT) and the Ministry of Oceans and Fisheries (MOF) announced the first release of the ocean color images taken by the GEO-KOMPSAT-2B satellite (Cheollian 2B, 3.4-ton class).
ㅇ Cheollian 2B was successfully launched on February 19 (Wed.), after which it reached its target geostationary orbit on March 6 (Fri.). The main satellite bus and payload were tested until recently, confirming that all systems are nominal.

□ Cheollian 2B conducted two performance tests of the GOCI-II (Geostationary Ocean Color Imager II) payload on March 23 and April 21-22. Though the payload is still undergoing the calibration phase, the first ocean color images of Korea as well as other parts of Northeast Asia and the surrounding sea area were seen to be very clear thereby demonstrating the excellent performance of Cheollian 2B.
ㅇ Cheollian 2B has a spatial resolution (500 meters → 250 meters) that is four times better than Cheollian 1 thus capable of providing much clearer images. It is expected to be able to provide quickly a wide range of marine information on the status of ports and coastal facilities that were difficult to identify before, changes in water quality in coastal waters, and the occurrence of oil spills.
ㅇ The performance improvement of Cheollian 2B is especially apparent when comparing its observation images with those of Cheollian 1. The enlarged images of the sea area near Incheon show a clearer view of the mudflat as well as the water quality characteristics of the west coast. Incheon Bridge can also be clearly seen, which was difficult to identify with images generated by Cheollian 1. Moreover, the clear images taken by Cheollian 2B of the Geumgang River and other streams in the Saemangeum region will now enable the acquisition of more precise information on the impact of freshwater on the sea.
ㅇ Cheollian 2B has four additional observation bands to facilitate more diverse and accurate marine observation. An observation band refers to a color band specialized for marine observation with optical wavelengths in the ultraviolet, visible and near-infrared bands. The 380 nm band images provide accurate information on the proliferation of marine pollutants and characteristics of atmospheric aerosols, the 510 nm and 620 nm band images on the concentrations of chlorophyll and suspended matter in the sea, and the 709 nm band images on marine and land vegetation.

□ The GOCI-II payload of Cheollian 2B will go through fine adjustments and calibration for optimization of the payload until it begins normal services through the Korea Ocean Satellite Center (KOSC) in October this year. It is expected to achieve its performance target without difficulty.

□ The GEMS (Geostationary Environment Monitoring Spectrometer) payload is also undergoing preparations to deliver observation images using hyperspectral information with all operations proceeding nominally as originally scheduled.
ㅇ The GEMS payload is the world’s first hyperspectral imager to operate in the geostationary orbit, requiring a longer period of time for testing and validation compared to the GOCI-II payload for which KOSC already has prior operational experience.
ㅇ The Ministry of Environment plans to complete software development for the calibration of hyperspectral observation data in May and begin the testing and validation of the observation data product in June and release the first atmospheric environment image around October.

□ “Cheollian 2B has been operating nominally by sending initial images that exceeded our expectations after reaching its targeted geostationary orbit in March. We plan to provide active support so that the marine and atmospheric environmental observation data sent by the satellite will lead to services that will enrich the people’s quality of life,” said Lee Chang-yun, director of Space, Nuclear & Big Science Policy at MSIT.

□ Meanwhile, MSIT as well as the relevant ministries have developed online education materials for Cheollian 2B considering the online school opening, for distribution through the websites of Edunet (www.edunet.net), Korea OpenCourseWare (www.kocw.net), and KARI (www.kari.re.kr)