Friday, December 7, 2012

இரவில் ஒளிரும் பூமி : நாசா (ஸ்பெஷல் வீடியோ)

இரவில் ஒளிரும் பூமி : நாசா (ஸ்பெஷல் வீடியோ)

Composite map of the world assembled from data acquired by the Suomi NPP satellite in April and October 2012.

நாசா விஞ்சானிகளால் இரவில் பூமியின் நிலை தத்வருபமாக ஆராயப்பட்டுள்ளது. NASA and National Oceanic and Atmospheric Administration (NOAA) satellite, என்பவை இணைந்து 2012 ஏப்ரல் மாதம் ஒன்பது நாட்களும்  அக்டோபர் மாதம் 13 நாட்களும் பூமியின் பல்வேறு மேற்பரப்புகளை படம் பிடித்து அனிமேசன் ஒலிப்பதிவை தயாரித்துள்ளனர்.

மேகங்கள் இன்றிய துல்லிய படங்கள் பூமியின் இயற்கையான மற்றும் மனிதனால் செயற்கையாக உருவாக்கப்  படைப்புகளால் இரவிலும் பூமி ஒளிர்வதை காட்டுகின்றது

This image of the continental United States at night is a composite assembled from data acquired by the Suomi NPP satellite in April and October 2012. The image was made possible by the satellite's "day-night band" of the Visible Infrared Imaging Radiometer Suite (VIIRS), which detects light in a range of wavelengths from green to near-infrared and uses filtering techniques to observe dim signals such as city lights, gas flares, auroras, wildfires and reflected moonlight.

On Oct. 13, 2012, the Visible Infrared Imaging Radiometer Suite (VIIRS) on the Suomi NPP satellite captured this nighttime view of the Nile River Valley and Delta.

ஆக்கத்தின் முழுவடிவத்தை ஆங்கிலத்தில் பார்வையிட ...

Scientists unveiled today an unprecedented new look at our planet at night. A global composite image, constructed using cloud-free night images from a new NASA and National Oceanic and Atmospheric Administration (NOAA) satellite, shows the glow of natural and human-built phenomena across the planet in greater detail than ever before.

Many satellites are equipped to look at Earth during the day, when they can observe our planet fully illuminated by the sun. With a new sensor aboard the NASA-NOAA Suomi National Polar-orbiting Partnership (NPP) satellite launched last year, scientists now can observe Earth's atmosphere and surface during nighttime hours.

The new sensor, the day-night band of the Visible Infrared Imaging Radiometer Suite (VIIRS), is sensitive enough to detect the nocturnal glow produced by Earth's atmosphere and the light from a single ship in the sea. Satellites in the U.S. Defense Meteorological Satellite Program have been making observations with low-light sensors for 40 years. But the VIIRS day-night band can better detect and resolve Earth's night lights.

The new, higher resolution composite image of Earth at night was released at a news conference at the American Geophysical Union meeting in San Francisco. This and other VIIRS day-night band images are providing researchers with valuable data for a wide variety of previously unseen or poorly seen events.

"For all the reasons that we need to see Earth during the day, we also need to see Earth at night," said Steve Miller, a researcher at NOAA's Colorado State University Cooperative Institute for Research in the Atmosphere. "Unlike humans, the Earth never sleeps."

The day-night band observed Hurricane Sandy, illuminated by moonlight, making landfall over New Jersey on the evening of Oct. 29. Night images showed the widespread power outages that left millions in darkness in the wake of the storm. With its night view, VIIRS is able to detect a more complete view of storms and other weather conditions, such as fog, that are difficult to discern with infrared, or thermal, sensors. Night is also when many types of clouds begin to form.

"It's like having three simultaneous low-light cameras operating at once and we pick the best of various cameras, depending on where we're looking in the scene," Miller said. The instrument can capture images on nights with or without moonlight, producing crisp views of Earth's atmosphere, land and ocean surfaces.

"The night is nowhere as dark as we might think," Miller said. And with the VIIRS day-night band helping scientists to tease out information from human and natural sources of nighttime light, "we don't have to be in the dark anymore, either."

"The remarkable day-night band images from Suomi NPP have impressed the scientific community and exceeded our pre-launch expectations," said James Gleason, Suomi NPP project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.