Selecting the Actual Channels

Chart of the 12 Meteosat channels • A solar channel since it reflects solar radiation<br/><br/>• Compared to other channels, the atmosphere is relatively transparent at solar wavelengths, producing a good view of surface features • A solar channel since it reflects solar radiation<br/><br/>• Compared to other channels, the atmosphere is relatively transparent at solar wavelengths, producing a good view of surface features • A solar channel since it reflects solar radiation<br/><br/>• Compared to other channels, the atmosphere is relatively transparent at solar wavelengths, producing a good view of surface features • A shortwave IR channel<br/><br/>• For the most part, it acts like a longwave IR channel, measuring emitted terrestrial and atmospheric radiation<br/><br/>• However, during daytime, it also reflects solar energy <br/><br/>• Has special abilities to detect fire and fog A longwave IR channel sensitive to water vapor in the atmosphere A longwave IR channel sensitive to water vapor in the atmosphere A longwave IR window channel capable of seeing low-level cloud and moisture features A longwave IR channel that highlights ozone detection A longwave IR window channel capable of seeing low-level cloud and moisture features A longwave IR window channel capable of seeing low-level cloud and moisture features A longwave IR channel that highlights carbon dioxide detection A high-resolution Vischannel with 1-km spatial resolution used for detailed close-up views of specific regions of interest

Now we're ready to select the channels for our product. Of the combinations below, which would produce the 'best natural' RGB product, one that emphasizes features such as topography, vegetation, and snow cover? (Choose the best answer.)

Note that for readability, we've removed the micrometer symbols following each channel's wavelength.

The correct answer is D.

The 0.6 µm Vis, 0.8 µm Vis, and 1.6 µm NIR (Near InfraRed) channels represent solar wavelengths that are effective for characterizing terrain and land cover features. Most of the other channels sense at shortwave, midwave, and longwave infrared wavelengths, only some of which can be used to detect surface features.