These two photographs acquired by Copernicus Sentinel-2 spotlight how the mission can assist distinguish between clouds and snow.
The Copernicus Sentinel-2 satellites every carry a high-resolution multispectral imager to offer optical photographs in 13 spectral bands, from the seen to the shortwave-infrared area of the electromagnetic spectrum. These two photographs, from August 2024, seize the identical space over the Australian Alps in southeast Australia, however have been produced utilizing the instrument’s completely different spectral channels.
On the left, the true-colour picture reveals the world because the human eye would see it. As we are able to see, the world is roofed with clouds. The lengthy, straight strains are contrails from plane, most certainly travelling alongside the busy route between Canberra and Melbourne.
The picture options quite a lot of snow-covered and cloud-covered areas, however how can we distinguish them? Each seem white, as they each mirror seen mild. That is the place completely different band mixtures can assist.
The false-colour picture on the proper contains the shortwave-infrared bands, which spotlight snow and clouds otherwise. Snow and ice seem in electrical blue, and water vapour, or clouds, may be seen in white.
By evaluating the 2 photographs, it’s now simple to determine snow in blue on the proper and thicker clouds in white in direction of the centre of the picture. Thinner layers of clouds and contrails then again are barely seen.
The duty of separating clouds from snow can also be a essential classification difficulty when utilizing Synthetic Intelligence (AI) to course of satellite tv for pc photographs – a area that’s quickly rising. By analysing multispectral photographs, the latest AI algorithms are studying to tell apart between these two components.
Satellite tv for pc missions similar to Copernicus Sentinel-2 that may present observations in a number of spectral bands are key to this process, offering a wealth of data in numerous views of our planet.
