Level zero data is raw data that comes off the instrument and level one data is data which has started to be calibrated from raw voltages.

Mattmann says that the public can have access, through the DAACs, to level two data. This is data that is calibrated, geospatially identified and mapped to a physical model (measurements that can be mapped in space and time).

"It's so voluminous, because it's raw measurements in space and time from an instrument. You probably won't use that in your IT organisations, it might be too big for you," he says.

It's when you get to level 3 data, which is typically mapped or gridded information, that the user can really "crank on it" because the files are lot smaller and more manageable, says Mattmann. This information is often used in discussions about temperature and climate change.

"With each level of processing there are more assumptions that are codified into the data. More scientific assumptions that you didn't necessarily make," Mattmann points out.