With either a built-in 500GB or 1TB hard drive, users have the ability to recordcontinuously for approximately 30 days or even longer when using the motion detection settings.
This record has been obtained and continuously updated by sensors onboard a series of land-imaging satellites that began with the launch of Landsat 1 in 1972.
"We can continuously observe and record the activity at the summit craters using our Web cams and thermal cameras, which send the images direct to Catania, " Calvari told CNN.
This extraordinary record of the diversity of American English is the longest continuously-funded project of the National Endowment for the Humanities.