I see the Party Lights| Off-Topic Discussion forum |

Gimp SuperDork
12/5/12 1:34 p.m.

Something we just published at work. Thought you guys might like it.

http://earthobservatory.nasa.gov/NightLights/

N Sperlo UltimaDork
12/5/12 1:36 p.m.

LOL. Nice.

Gimp SuperDork
12/5/12 9:22 p.m.

I've opened a beer, so I guess my 14 hour work day is almost over. Getting lots of traffic is great for the site, but hell on the web developer (me).

N Sperlo UltimaDork
12/5/12 9:32 p.m.

LOL. My three choices for college studies. IT, Mechanical Engineering, Law Enforcement. I'm glad I picked law enforcement. I'd never survive in front of a screen. I'm checking out the full site now. I love sparklies.

I'll join you with a beer. Do the astronauts get space beer?

N Sperlo UltimaDork
12/5/12 9:36 p.m.

How were these pictures made? Is it just art work or is there something more technical in those floaty things in space?

Gimp SuperDork
12/5/12 10:36 p.m.

N Sperlo wrote: How were these pictures made? Is it just art work or is there something more technical in those floaty things in space?

My unofficial version as the EO's web monkey:

There is a new hunk 'o tin overhead, with a thing on it called VIIRS. VIIRS is neat because it can see in low light, and it loops around the earth without leaving any holes in the picture (think being a movie badass and peeling an orange with knife at your first prison luncheon). There were enough good passes between April and ______ that there was enough "DATA" for a could free image. Convert the data (ones and zeros) into an image, look at each and find the cloud free ones, stitch them together, and you get global image. Notice I never once said the word "photo."

Quoting from my colleagues:

"A handful of scientists have observed earthly night lights over the past four decades with military satellites and astronaut photography. But in 2012, the view became significantly clearer. The Suomi National Polar-orbiting Partnership (NPP) satellite — launched in October 2011 by NASA, the National Oceanic and Atmospheric Administration (NOAA), and the Department of Defense — carries a low-light sensor that can distinguish night lights with six times better spatial resolution and 250 times better resolution of lighting levels (dynamic range) than before. Also, because Suomi NPP is a civilian science satellite, data is available to scientists within minutes to hours of acquisition.

The Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP can observe dim light down to the scale of an isolated highway lamp or fishing boat. It can even detect faint, nocturnal atmospheric light — known as airglow — and observe clouds lit by it. Through the use of its “day-night band,” VIIRS can make the first quantitative measurements of light emissions and reflections, distinguishing the intensity and the sources of night light. The sum of these measurements gives us a global view of the human footprint on the Earth."

...

"NPP Suomi and its VIIRS instrument pass over any given location on Earth at roughly 1:30 a.m. and 1:30 p.m. local time each day, observing the planet in vertical strips from pole to pole. VIIRS is a spectroradiometer, detecting photons of light in 22 different wavelength bands and collecting them in a similar fashion to the charge-coupled device in your digital camera."

...

"Unlike a film camera that captures a photograph in one exposure, VIIRS produces an image by repeatedly scanning a scene and resolving it as millions of individual picture elements, or pixels. The day-night band goes a step further, determining on-the-fly whether to use its low, medium, or high-gain mode to ensure that each pixel accurately depicts the amount of light emitted."