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進入《TAIPEI TIMES》NSPO trumpets satellite’s performance
The Pratas Islands （Dongsha Islands） are pictured in an undated photograph taken by the Formosat-5 satellite. Photo courtesy of the National Space organization
ON A ROLL: With Formosat-5 up and running, the NSPO plans to launch 10 satellites by the end of 2028, and update its integration and testing facilities for satellite instruments
By Lin Chia-nan / Staff reporter
The images taken by Taiwan’s first indigenously developed satellite, Formosat-5, has been used to calculate underwater topography and monitor rice production after it became commercially operational last year, and its performance is comparable to that of a US high-resolution satellite, the National Space Organization （NSPO） said yesterday.
The NSPO, a National Applied Research Laboratories affiliate, yesterday at a news conference in Taipei touted the academic applications of images taken by Formosat-5.
The optical remote sensing satellite was launched on Aug. 25, 2017, from Vandenberg Air Force Base in California on a Falcon 9 rocket built by Space Exploration Technologies Corp, commonly known as SpaceX.
It became commercially operational in September last year, and has been transmitting black-and-white images with a resolution of 2m and color images with a resolution of 4m.
Huang Chih-yuan （黃智遠）, an associate professor at National Central University’s Center for Space and Remote Sensing Research, said that his team used the satellite images to map the underwater topography around the Pratas Islands （Dongsha Islands, 東沙） using an “artificial neural network” computing method.
Compared with WorldView-2, a commercial imaging satellite with better resolutions, Formosat-5 images only have a margin of error of up to 40cm, meaning the two perform similarly, he said.
Whether the difference matters depends on areas of application, he added.
While the satellite cannot take underwater images as deep as sonar equipment, it can save costs for in situ surveys of places where the topological relief is not that significant, he added.
Chu Tzu-how （朱子豪）, a professor at National Taiwan University’s Spatial Information Research Center, said that his team used the satellite images to calculate the areas of rice fields in Taiwan, with an accuracy level of 90.05 percent.
The Agricultural Research Institute in August sparked controversy when it was found to have attempted to buy images sourced from a China-based firm for monitoring crop production.
Only China’s Zhuhai-1 remote sensing satellite constellation could satisfy the institute’s requirements for image resolution better than 10m with more than 30 wavebands, the institute said at the time.
Asked about the issue yesterday, Chu said that purchases of satellite images can be purely commercial transactions, avoiding confidential data.
Countries owning satellites also share information for disaster-relief purposes, he added.
While Formosat-5 has only four wavebands, they are sufficient for most agricultural survey missions, he said.
The NSPO is planning to launch 10 satellites from this year through 2028: six high-resolution satellites, two ultra-high-resolution satellites and two synthetic aperture radar satellites, NSPO Director-General Lin Chun-liang （林俊良） said.
It is also updating its integration and testing facilities for satellite instruments, and preparing standard specification guidelines for the manufacture of related components, Lin added.
新聞來源：TAIPEI TIMES
A model of the Formosat-5 satellite is pictured in Yunlin County on March 21 last year. Photo: Chan Shih-hung, Taipei Times
