WESTERN AUSTRALIA BY LANDSAT
The USGS posted this glorious image of Western Australia from a Landsat 8 Image. The colors – so beautiful! – demonstrate even to my uneducated eyes (well, I haven’t worked much with satellite images) variations in the apparent jungle-type vegetation around the estuary and the minute differences in sediment and nutrient levels within the water.
This is an “enhanced” Landsat image, and by enhancement, it’s a bit more complex than what you or I would run through “photoshop” to make Aunt Maria’s teeth look more… white. The satellite takes images in specific spectrum – some are visible to our eyes, and others are not, as for those in the infrared. Even when taking a photo in the visible spectrum, the preliminary result is not a “pretty picture” as if taken from an airplane or by an astronaut in the space station. The visible colors that are chosen are individual wavelengths of light that we, by chance, can see. The satellite may be set to pick out “yellow” at a certain wavelength, or several wavelengths close to that yellow, or it may look for unhealthy forest by trying to find shades of brown or red. Our eyesight is generally better – we see the spectrum as a continuous range of coloring, while the satellite picks and chooses single wavelengths. But in this way, it can concentrate on the minute differences among spectra that give us a detailed photo, demonstrating minute differences in color that our eyes can’t pick out. The spectra chosen emphasize certain features in the environment – in some cases, the resultant image may show urban areas as pink, lovely lakes as black, and volcanoes deep red, though if you were to go there, they’d look brown or black.
And Voila – the Western Australian photo.
Annie R Thank you, USGS! And their credit is to Geoscience Australia, a Landsat International Cooperator and a Landsat Science Team Member, produced this enhanced image.
https://www.facebook.com/photo.php?fbid=602773303101990&set=a.169734339739224.34845.102635589782433&type=1&theater
And do take the Landsat Tutorial offered at: http://geology.com/satellite/landsat-images.shtml
