We cannot protect our planet if we cannot understand it. Understanding a complex system requires accurate measurements and quantification of dynamic processes. The Landsat Program is a series of Earth-observing satellite missions jointly managed by NASA and the U.S. Geological Survey (USGS).Landsat missions span for more than half a century starting from 1972. The unbroken sequence of images covering the entire Earth’s surface provide an invaluable record of historical land use. In this second episode of the four part mini series, we explore the technical developments leading to the most recent design in the Landsat program: Landsat 9. The episode introduces the sensors on board Landsat 9 including the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). The most recent satellite in the series Landsat 9 has been launched in orbit on September 27, 2021 and is now operational.
The early designs of Landsat satellite sensors could only operate within visible light range. More recent Landsat designs, including Landsat 9, have two advanced sensors: the Operational Land Imager (OLI-2) and the Thermal Infrared Sensor (TIRS-2). These sensors can collect data at near-infrared, shortwave-infrared, and thermal infrared wavelengths. By comparing observations of different wavelengths, scientists can identify algal blooms, storm damage, fire burn scars, the health of plants, and more.
Since 2008, the entire Landsat archive is freely available to all.
Landsat 9: part 1, Getting Off The Ground
Landsat 9: part 2, Designing For The Future
Landsat 9, part 3: More Than Just A Pretty Picture
Landsat 9, part 4: Plays Well With Others
1 Comment