False Color (Urban)
False color composites allow us to visualize the wavelengths the human eye does not see (near the infrared range). The use of bands, such as near infrared, increases spectral separation and can enhance the interpretability of data. False color images are a representation of a multispectral image created using ranges other than visible red, green and blue, such as red, green and blue image components. There are many different false color compositions that can distinguish many different functions.
SWIR 2, SWIR 1, Red
This combination is used to obtain pseudo-natural colors under certain conditions when the image is visualized similar to the natural one and allows you to analyze the atmospheric haze, the state of suspensions in the atmosphere, its smoke.
Vegetation is visible in shades of green, urbanized areas are represented by white, gray, or purple, and soils, sand, and minerals are shown in a variety of colors. Due to the almost complete absorption of solar radiation in the middle IR range by water, snow, and ice, coastlines and water objects are well distinguished. Snow and ice appear as dark blue, and water as black or blue. Flooded areas are a very dark blue and almost black, whereas in composition 3-2-1, shallow flooded areas are gray and difficult to distinguish.
One application of this combination is the monitoring of forest fires. Surfaces with elevated temperatures, such as forest fires and calderas of volcanoes, saturate the image in medium IR channels and are displayed in shades of red or yellow.