For the true color rendition, band 1 is displayed in the blue color, band 2 is displayed in the green color, and band 3 is displayed in the red color. The resulting image is fairly close to realistic - as though you took the picture with your camera and were riding in the satellite. But it is also pretty dull - there is little contrast and features in the image are hard to distinguish.
Custom script: return [B03, B02, B01];
In this SWIR image, band 2 is displayed in blue, band 4 is displayed in green, and band 7 (or 5) is displayed in red. This rendition looks like a jazzed up true color rendition - one with more striking colors.
Custom script: return [B07, B05, B04];
In this image, band 2 is displayed in blue, band 3 is displayed in green, and band 4 is displayed in red. This rendition looks rather strange - vegetation jumps out as a bright red because green vegetation readily reflects infrared light energy! It is similar to pictures taken from aircraft when using infrared film; very useful for studying vegetation.
Custom script: return [B02, B03, B04];
Resolution = 15 m/px
Bandwidth = 0.52-0.9 µm
Purpose = only Landsat 7 has a 15 m panchromatic sharpening band used to “sharpen” images.
Resolution = 30 m/px
Bandwidth = 2.09-2.35 µm
Purpose = limited cloud penetration; provides good contrast between different types of vegetation; useful for measuring the moisture content of soil and vegetation; helps differentiate between snow and clouds.
Resolution = 60 / 120 m/px*
Bandwidth = 10.4-12.5 µm
Purpose = useful to observe temperature and its effects, such as daily and seasonal variations; useful to identify some vegetation density, moisture, and cover type.
* The thermal band on Landsat 7 (ETM+ sensor) has a spatial resolution of 60 m; it is 120 m on Landsats 5 (TM sensors).
Resolution = 30 m/px
Bandwidth = 1.55-1.75 µm
Purpose = limited cloud penetration; provides good contrast between different types of vegetation; useful for measuring the moisture content of soil and vegetation; helps differentiate between snow and clouds.
Resolution = 30 m/px
Bandwidth = 0.75-0.90 µm
Purpose = good for mapping shorelines and biomass content; very good at detecting and analyzing vegetation.
Resolution = 30 m/px
Bandwidth = 0.63-0.69 µm
Purpose = limited water penetration; reflects well from dead foliage, but not well from live foliage with chlorophyll; useful for identifying vegetation types, soils, and urban (city and town) features.
Resolution = 30 m/px
Bandwidth = 0.525-0.605 µm
Purpose = penetrates clear water fairly well, gives excellent contrast between clear and turbid (muddy) water; helps find oil on the surface of water, and vegetation (plant life); reflects more green light than any other visible color; man-made features are still visible.
Resolution = 30 m/px
Bandwidth = 0.433–0.453 µm
Purpose = scattered by the atmosphere and illuminates material in shadows better than longer wavelengths; penetrates clear water better than other colors; absorbed by chlorophyll, so plants don’t show up very brightly in this band; useful for soil/vegetation discrimination, forest type mapping, and identifying man-made features.
