Embedded Files
The most straightforward type of satellite imagery is visible imagery. The word "visible" doesn't mean that it's imagery you can see; it means that the sensor is detecting radiation within the visible wavelength range. This consists mostly of sunlight reflected or scattered back to the satellite. The standard weather satellites just detect the amount of radiation without breaking it down into individual colors, so the image is effectively black and white.
Here's an example of a visible satellite image. This image was taken on August 30th, 2015. The continental outlines have been added. The most direct application of visible satellite images is in the identification of clouds, and in this image, a good portion of the visible surface is covered in different types of clouds. Since clouds are white: they scatter most of the incoming radiation from the sun back into space, where it is detected by the satellite.
Meanwhile, over the part of the Earth that is free of clouds, it is possible to make out various geographical features. Bodies of water typically appear darker than land surfaces. Similarly, areas of vegetation typically appear darker than deserts. What is the small white spot circled in red the image?
Report abuse