Civilian remote sensing satellites have been operating since the early 1970s, allowing us to chart major changes on the Earth's surface over recent decades. Modern weather and research satellites provide a constant stream of data allowing the Earth's oceans, atmosphere and biosphere to be monitored. We can process this data into time sequences showing seasonal, daily and even hourly changes.
We produce change maps and time sequences by combining images taken on different dates or times of day, correcting for geometric, colour and brightness differences, eliminating data noise, and combining with background or reference data where necessary.