Satellites: Make Earth Observations Open Access

...A new era of open-access satellite data has arrived. In 2008, the US Geological Survey (USGS) released for free to the public its Landsat archive, which dates back to the 1970s and is the world's largest collection of Earth imagery². Greater computing power is also enabling scientists to manipulate big data representing larger areas and with greater sophistication, to produce multibillion-pixel composite maps of land cover and change across regions, continents and the globe. Monitoring land-cover change in near-real time is now a reality.

Obstacles remain. Data coverage in the Landsat archive is variable, in both space and time (see 'Global coverage'). And few people have enough computing power and bandwidth to download and manipulate the data. Decision-makers remain largely unaware of the vastly improved opportunities for environmental monitoring offered by the latest methods, and so are not yet using such data to their full potential.

Scientists and policy-makers can support the shift to open-access satellite data, and coordinate efforts to deliver the detailed global monitoring required by international climate change and emissions-reduction programmes. Further, governments should open up their national satellite image archives and integrate compatible data to fill gaps. And satellite imagery from future missions should be freely accessible to all to promote innovation and use...