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A £100m project has been announced to launch three new British spacecraft to image the surface of the Earth.

The satellites, to be orbited in 2013, will be able to see details down to one metre at their best resolution.

It is a commercial venture between the spacecraft manufacturer Surrey Satellite Technology Limited and its data processing subsidiary, DMCii.

Nations that would not necessarily need their own dedicated satellites will be able to buy time on the spacecraft.

"This constellation of three satellites will be owned and operated from the UK but the capacity on the spacecraft will be leased to different international customers," explained Sir Martin Sweeting, executive chairman of SSTL.

The Guildford-based entrepreneur made the announcement in the Czech capital, Prague, which is hosting this year's International Astronautical Congress.

SSTL and DMCii already operate a fleet of 100kg-class imaging satellites, but these are owned by different nations, including the UK, China, Spain and Nigeria.

DMCii acts as their business manager, processing and distributing their data, and collecting any revenues earned from selling the satellites' pictures to third-party customers.

There is a burgeoning worldwide business in imaging the surface of the planet for all sorts of applications, from making street plans to policing deforestation.

Surrey Satellite has become a world leader in manufacturing small spacecraft for this purpose, lowering costs by making the most of off-the-shelf components developed for ordinary consumer electronics, such as laptops.

SSTL is a spin-out from the University of Surrey. It says its profitable business owes a great deal to government seed-funding 10 years ago that enabled it to test key technologies and market opportunities.

Sir Martin said there had been a 20-to-one return on this investment.

"We're not asking government to fund grand space programmes," he told 91�ȱ� News. "But there are some technologies and some business cases that we need the help of government just to get us over the hump - to get the wheels turning."

The new project's roughly £100m cost covers about £60m for the satellites themselves with the rest going on launch and insurance fees.

The spacecraft would be built to a tight timeline, which could see them ready for launch on a single rocket by the end of 2013.

Each satellite will be in a larger class than the current DMCii-managed fleet, topping over 300kg.

As well as their high resolution cameras (1m/pixel resolution panchromatic; 4m/pixel resolution colour), they will also accommodate imagers capable of mapping ultra-wide strips (600km) of the Earth's surface, albeit at resolutions above 20m.

This broad-swath facility will allow DMCii to continue to use the new satellites for disaster response. Its current fleet plays a leading role in acquiring the urgent maps needed by relief agencies when a natural or man-made calamity strikes a particular corner of the world.

The satellites have been particularly active this year in monitoring the impacts of the BP oil spill in the Gulf of Mexico.

Jonathan.Amos-INTERNET@bbc.co.uk