In 2003, NASA launched the ICESat satellite to monitor the state of ice in the polar regions of the planet, and now it's time for ICESat-2. It carries the "Advanced Topographic Laser Altimeter System" or, simply put, the most advanced altimeter in NASA history. Its main task is to constantly measure the thickness of the ice with unprecedented accuracy.
ICESat-2 will constantly move from pole to pole, taking measurements four times a year. It emits six separate laser beams, each with hundreds of trillions of photons, and then measures the time it takes for them to reflect and return back to within one billionth of a second. The coverage density is also unprecedented - if the old satellite made two measurements on an area the size of a football field, then the new one will make a map of 130 points and will be able to notice height differences of 1 cm or less.
The main object of interest of the ICESat-2 mission is undoubtedly the ice cover of the poles. However, if necessary, the satellite altimeter can be directed to other important objects, for example, to measure the water level in rivers and the height of snow. It can be used to track the rate of melting of both glaciers and already drifting ice floes, even measure the height of a forest in order to calculate the indirect carbon content in them and predict the likelihood of forest fires.
According to Torsten Markus, the lead developer of ICESat-2, this is not a universal tool, but very close to that. Actually, one of the secondary missions is to study the capabilities of a unique altimeter, in relation to real situations on the planet. The launch of the carrier rocket with the satellite is scheduled for September 15th.