[Faline]

This spectacular night-time view of Earth is called Black Marble.

It has been assembled from a series of cloud-free images acquired by one of the most capable satellites in the sky today - the Suomi spacecraft.

The platform was launched by the US last year, principally to deliver critical meteorological data.

The Black Marble dataset shows off one of Suomi's key innovations: the low-light sensitivity of its VIIRS instrument.



VIIRS (Visible Infrared Imaging Radiometer Suite) can discern a range of phenomena of interest to weather forecasters - cloud, snow, fog, etc - even when the satellite is on the dark side of the Earth.

Most of the time, all VIIRS needs to do its work is some illumination from the Moon. But if that is not available, the instrument can still detect features down below just from the nocturnal glow of the atmosphere itself.

And, of course, just as this Black Marble rendition demonstrates, VIIRS is also very good at capturing the lights of our cities.

The new imagery was unveiled here at the American Geophysical Union (AGU) Fall Meeting, the largest annual gathering of Earth scientists.

Data from Suomi - a joint Nasa and National Oceanic and Atmospheric Administration (NOAA) satellite - is certain to become a mainstay of future presentations at this conference.

VIIRS' trick is its special day-night band. Unlike a camera that captures a whole picture in one exposure, the day-night band produces an image by repeatedly scanning a scene and resolving it as millions of individual pixels.

The system then reviews the amount of light in each pixel. If it is very bright, a low-gain mode prevents the pixel from oversaturating; if the pixel is very dark, the signal is amplified.

US Air Force satellites have pushed the development of low-light sensors for decades but Nasa/Noaa representatives at the AGU meeting said VIIRS had taken the capability to a new level.

One of the instrument's most important observations of late was to watch Hurricane Sandy as it made landfall over the US in October.

Suomi was launched as the NPP (National Polar-orbiting Operational Environmental Satellite System Preparatory Project) satellite.

It was subsequently renamed in honour of the pioneering Earth observation scientist Verner E Suomi. The two-tonne, $1.5bn (£0.9bn) spacecraft circles the globe, pole to pole, at an altitude just over 800km.

Its five instruments are tasked with monitoring a huge range of land, ocean, and atmospheric phenomena - from the temperature and humidity of the air, to the spread of algal blooms in the ocean; and from the amount of sunlight bouncing off clouds to the extent of Arctic ice.

[Viking64]

Astonishing!!!

[kellyhound]

Scientists unveiled 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."

"NOAA's National Weather Service is continuing to explore the use of the day-night band," said Mitch Goldberg, program scientist for NOAA's Joint Polar Satellite System.

"The very high resolution from VIIRS data will take forecasting weather events at night to a much higher level."

Unlike a camera that captures a picture in one exposure, the day-night band produces an image by repeatedly scanning a scene and resolving it as millions of individual pixels.

Then, the day-night band reviews the amount of light in each pixel. If it is very bright, a low-gain mode prevents the pixel from oversaturating. If the pixel is very dark, the signal is amplified.

"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."

Click For Higher Resolution.

[Brometheus]

damn the whole NYC is nothing but lights..

[mcpronoun]

[Sharon]

Fantastic technology, love those images!!