Sunday, December 28, 2014

Planet Earth in 4K

James has put together a time lapse of Earth in based on images obtained from the geostationary Elektro-L weather satellite. The dates of this time lapse are from May the 15th to May 19th, 2011.

The weather satellite Elektro-L is located  at 40,000 km above the Indian ocean. It orbits at a speed that causes it to remain over the same spot while the Earth rotates. The satellite creates a 121 megapixel image (11136x11136 pixels) every 30 minutes with visible and infrared light wavelengths.

James said that the images were edited to adjust levels and change the infrared channel from orange to green to show vegetation more naturally.

James includes some additional information on his YouTube based post around questions that people ask. Why are city lights, the Sun, and other stars not visible? City lights are not visible he says, because they are thousands of times less bright than the reflection of sunlight off the Earth. If the camera was sensitive enough to detect city lights, the Earth would be overexposed. The Sun is not visible due to mechanisms used to protect the camera CCD from direct exposure to sunlight. A circular mask on the CCD ensures that only the Earth is visible. This mask can be seen as pixelation on Earth's horizon. The mask also excludes stars from view, although they would not be bright enough to be visible to this camera.

Here is the Earth from 40,000 km's away. You can find the direct link below if you want to watch this in a larger version and that link will also provide you with the ability to increase the video's resolution. As even though this video is based on high resolution images, which James spoke of, you are only seeing it by the youtube default quality of 480p. You can change that to 1080p within YouTube's settings on the actual video it self. Below the video I have included a screen shot of what I mean.

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