The Ministry of Science and Technology announced on Tuesday that a large surveillance network will be set up to monitor water reserves, forests, farmland, urban development and changes.

The project's main goal is to make it possible to obtain data on any event at any given time from space by sending over 100 observation satellites by 2020.

China regularly sends research satellites into orbit and in October last year it became the third nation to successfully put a human in space.

Last month, the retrievable chamber of its 20th recoverable satellite returned to Earth with a bang, crashing through the roof of a house.

And in August, a satellite was launched that carried out land and mapping surveys for several days before returning to Earth.

Sun Laiyan, director of the China National Space Administration?(CNSA), said that a large satellite-based earth observation system will also be built by 2010. The system could be used for observation of land, atmosphere and ocean within China, its adjacent areas and even the entire globe.

He was speaking at the opening ceremony of the 18th plenary session of the Committee for Earth Observation Satellites (CEOS), an international non-governmental organization set up in 1984 to focus on air-to-surface observation.

Sun said that China will develop a new generation of polar orbit and stationary orbit meteorological satellites, high-performance resource follow-up satellites, oceanic color and dynamic observation satellites.

It will also set up a mini-satellite constellation for environmental and disaster monitoring. Construction of the constellation will be done in two phases. The first phase would see deployment of three satellites. In the second phase, eight more satellites would be put in place, said Sun.

"We will complete the first phase before 2007. We welcome international collaboration to complete the second phase before 2010," he said.

"The CNSA wishes to enhance exchanges and cooperation with other countries in the field of earth observation, to contribute more to peaceful use of outer space," Sun said.

Some 300 officials and specialists from home and abroad attended the conference, to discuss how to study global water resources, disaster monitoring and other issues through earth observation technology.

The first earth meteorological satellites were developed in 1960. Since then, many countries have developed their own earth observation technology. CEOS was formed to coordinate worldwide efforts for civil earth observation.

Results of earth observation are used in atmospheric, ocean and land studies as well as agriculture, industry and business sectors.

To celebrate the 20th anniversary of CEOS, which China joined in 1991, officials from the World Meteorology Organization, the European Space Administration and other international organizations delivered speeches yesterday.

An exhibition of remote-sensing technology, global positioning systems, space science and other earth observation-related technological achievements was held and will last until Thursday.

(CRI.com, China Daily November 17, 2004)