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Ursprungligen postat av
studenten777
quora tråden jag postade handlar om blue marble. vida känt och i efterhand erkänt att det är ihopklippt. sorry!
quora tråden du länkade handlade om en "blue marble" bild, inte om bilden The Blue Marble.
Det här är bilden som togs av besättningen på Apollo 17 från 29 000 km höjd den 7 december 1972 (med analog kamera) och fick namnet The Blu Marble
https://spaceflight.nasa.gov/gallery/images/apollo/apollo17/hires/as17-148-22727.jpg
NASAs namn på bilden är AS17-148-22727
https://spaceflight.nasa.gov/gallery/images/apollo/apollo17/html/as17-148-22727.html
Bilden du länkar till på quora:
https://www.quora.com/Why-do-the-clouds-look-like-duplicates-in-this-picture-of-the-earth
är som framgår av texten sammansatt av bilddata insamlad under månader. Bilderna är tagna från 700 km höjd
This spectacular “blue marble” image is the most detailed true-color image of the entire Earth to date. Using a collection of satellite-based observations, scientists and visualizers stitched together months of observations of the land surface, oceans, sea ice, and clouds into a seamless, true-color mosaic of every square kilometer (.386 square mile) of our planet. These images are freely available to educators, scientists, museums, and the public.
Much of the information contained in this image came from a single remote-sensing device-NASA’s Moderate Resolution Imaging Spectroradiometer, or MODIS. Flying over 700 km above the Earth onboard the Terra satellite, MODIS provides an integrated tool for observing a variety of terrestrial, oceanic, and atmospheric features of the Earth. The land and coastal ocean portions of these images are based on surface observations collected from June through September 2001 and combined, or composited, every eight days to compensate for clouds that might block the sensor’s view of the surface on any single day. Two different types of ocean data were used in these images: shallow water true color data, and global ocean color (or chlorophyll) data. Topographic shading is based on the GTOPO 30 elevation dataset compiled by the U.S. Geological Survey’s EROS Data Center. MODIS observations of polar sea ice were combined with observations of Antarctica made by the National Oceanic and Atmospheric Administration’s AVHRR sensor—the Advanced Very High Resolution Radiometer. The cloud image is a composite of two days of imagery collected in visible light wavelengths and a third day of thermal infra-red imagery over the poles. Global city lights, derived from 9 months of observations from the Defense Meteorological Satellite Program, are superimposed on a darkened land surface map.
Termen "blue marble" har kommit att användas på fler bilder än originalet The Blue Marble från 1972 och det framgår tydligt att de bilderna är sammansatta av många bilder tagna från lågt flygande satelliter för att få en sammansatt bild med hög upplösning:
https://en.m.wikipedia.org/wiki/The_Blue_MarbleSubsequent similar images of Earth (including composites at much higher resolution) have also been termed Blue Marble images, and the phrase "blue marble" (as well as the picture itself) is frequently used
NASA has also applied the name to a 2012 series of images which cover the entire globe at relatively high resolution. These were created by looking through satellite pictures taken over time in order to find as many cloudless photographs as possible to use in the final images.
