New South Wales state authorities have successfully prosecuted and fined a company for clearing land illegally after analysing satellite imagery of its activities.

In December 2006 Olmwood Limited cleared the land for a gold course without permission. The company claimed it did not know that it needed permission and pleaded not guilty.

But after an eight day trial the firm was convicted, fined $100,000 and ordered to pay the prosecutor's legal costs.

Department of Environment, Climate Change and Water (DECCW), Acting Director General, Simon Smith said this result sends a strong message to developers who try to clear land prior to proper assessment by planning authorities.

"DECCW's aerial imagery of the Greater Taree and Old Bar areas confirmed the timing and magnitude of the native vegetation destruction,” he said.

The authority uses computerised analysis of satellite imagery and aerial photography of the entire state to identify locations where vegetation change appears to have occurred. This data is then screened to identify sites for investigation.

"Developers conducting illegal broad scale land clearing cannot hide from satellites,” said Smith.

In May the department began a high tech education campaign to encourage compliance with native vegetation laws by sending letters to landholders including before and after satellite pictures identifying land clearing.

DECCW Director-General Lisa Corbyn said the letters were part of an ongoing education program to encourage compliance with the laws and inform landowners of the proper channels available to them if they want to clear native vegetation.

"We've been using satellite technology for some time to identify changes in vegetation cover that may warrant further investigation," Ms Corbyn said. "Now we are also using the technology as an education tool.”