BEIJING, June 16 (China Space News) —  China's first high orbit remote sensing satellite, Gaofen-4, went into use after six months of in-orbit testing, the State Administration of Science, Technology and Industry for National Defense (SASTIND) announced Monday.

Gaofen-4 is China's first geosynchronous orbit high-definition optical imaging satellite and the world's most sophisticated.

Gaofen-4, which was launched in December 2015, has a designed lifespan of eight years, compared to other remote sensing satellites which remain in service for less than three to five years.

During the in-orbit test, Gaofen-4 has been used to collect imageries of flood-hit areas in south China and monitor fires that occurred in southwest China's Sichuan Province and in Russia.

China started the Gaofen project with the launch of Gaofen-1 in April 2013. It aims to launch seven high-definition observation satellites before 2020, designed for disaster prevention, surveillance of geological disasters and forest disasters and weather forecast.