In 1999 and 2002, America’s NASA launched two satellites that together furnished the capability to observe every part of the earth’s surface once or twice each day. For over two decades scientists worldwide have been using data from this pair of satellites, which observe a multitude of phenomena, including cloud and aerosol cover, the distribution of vegetation on land, changes in land use, land and sea surface temperatures, fires, eruptions, snow accumulation, and sea ice. But the two satellites have been operating for more than three times as long as originally planned, and their observational instruments are beginning to show wear and tear.
SHIKISAI, which has observational capabilities superior to those of the two NASA satellites, is tasked with surveying the entire earth and supplying data for various purposes. Among these is creating a map of vegetation distribution. The Japanese Ministry of Environment has created a map of vegetation distribution in Japan called the Green Census, which is the world’s most detailed record of its kind. It is hoped that the use of SHIKISAI's observational data can be extended to the whole of Asia and contribute to the provision of information on global vegetation. JAXA started supplying data from SHIKISAI in December 2018, in place of the overseas satellite data previously used in Japan. SHIKISAI flies at an altitude of 800 kilometers observing everything happening on the earth’s surface. Scientists all over the world, have very high expectations of the outcome.