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The Sharpest Ever Global Earth Map
Roland Piquepaille writes "The GLOBCOVER project, started by the European Space Agency (ESA), has a very simple goal. It will create the most detailed portrait of the Earth's land surface with a resolution three times sharper than any previous satellite map. The image acquisition will be done throughout 2005 and use the Medium Resolution Imaging Spectrometer (MERIS) instrument of the Envisat environmental satellite. To create this sharp map, the GLOBCOVER project will analyze about 20 terabytes of data gathered by the European satellite. When it's completed, the map will have numerous uses, 'including plotting worldwide land use trends, studying natural and managed ecosystems and modelling climate change extent and impacts.'"
time to put something interesting on the roof for when the sat passes over
The image acquisition will be done throughout 2005 and use the Medium Resolution Imaging Spectrometer (MERIS) instrument of the Envisat environmental satellite.
Surely the High Resolution Imaging Spectrometer would be more appropriate?
Niles will be happy to hear she's orbiting the planet...
Obliteracy: Words with explosions
I can see my house!
shit... better throw a tarp over my missles...
Now when this is incorporated into maps.google.com I'll be even happier..
A computer without Microsoft is like ice cream without ketchup.
(BTW, I *highly* recommend checking out World Wind if you haven't seen it. It is one of the most awesome programs ever to exist, bar none.)
main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
Well but isn't this data for which I've paid with my tax euros already? Why does the public who financed it not get free access to that data?
While we're at it, can other Slashdotters perhaps point to links of freely available satellite imagery? Is there any kind of systematic coverage of the planet we live on which is freely available to everyone who does happen to live here?
"The image acquisition will be done throughout 2005 and use the Medium Resolution Imaging Spectrometer" So if they want to create the sharpest map, wouldn't it be best to use the High Resolution Imaging Spectrometer? Duh....
The estimate is that up to 20 terabytes of imagery will be needed to mosaic together the final worldwide GLOBCOVER map - an amount of data equivalent to the contents of 20 million books.
Why do writers insist on making these kind of useless comparisons? Is there any research that indicates the average book contains the equivalent of one megabyte of data? Especially one megabyte of imagery? Will this really help a layperson quantify a terabyte?
This just in: The human brain is capable of storing an amount of data equivalent to 68 quintillion index cards.
Yes, *that* Bob Vila.
So the most important question is how big does my sign have to be?
-- Thou hast strayed far from the path of the Avatar.
That area without the trees...it's called the ocean.
MERIS grabs data in up to 15 spectral bands with 16 bits per band per pixel. Its only has a 1/2 megapixel imager (842 x 691), but the RAW images are 17.5 MB.
Multispectral data is great for identifying ground cover (e.g, classifying the types of plants, health of plants, minerals, etc. on the ground). Sometimes, it's more valuable to know the materials on the ground than to see the geometric detail.
Two wrongs don't make a right, but three lefts do.
You could download Nasa Worldwind software for free.
There are some issues with Landsat7 data, but hopefully they will get fixed soon.
Its awsome piece of software! offers 7m resolution globally and offers 1m resolution for USA.
On the other hand, ESA has always been stingy in giving access to data. It took them a while to release Titan images; as opposed to Nasa who makes them available almost instanteneously.
I guess thats the difference between the cultures!
- Sh!t
You are missing something.
The resolution of this bird is 300 meters, in many more wavelengths than just visible - multiple longband IR, optical, synthetic apeture millimeter radar.
It's like the difference between a 1920x1080 one bit per pixel image and a 640x480 Truecolor image.
www.eFax.com are spammers
The fact is, there is more vegetation on the planet now than there was 100 years ago
I call bullshit.
State your references or admit you're pulling 'facts' out of your ass.
____
~ |rip/\/\aster /\/\onkey
Reading the article, it really is 300m/pixel. This is 400x lower resolution than the 15m Landsat data that is available as a basemap in Keyhole, Google Maps, and other providers.
The reason this data is interesting is its 15-band nature and the amount of analysis and extraction that can be done from it.
For pretty pictures, there are plenty of better sources.
There is a huge difference between the 'google maps' visual coverage, and this, which is a 'earth surface condition map'. For one, the resolution here is pathetic compared to that of the 'google maps', but it has a completely different goal. It is intended to show details about land, instead of whether or not someone mowed a 'hi mom' message into their lawn. Move along, you won't be seeing that any time soon.
Current multispectral stuff is more than 300m? Interesting, it would miss entire steams, even rivers and stuff.
Good point and that seems plausible, but is not entirely true. With a good pixel-mixing analysis you can resolve stuff inside the pixel. The key is having a clean spectral model for the terrain versus water and being able to say that a given pixel looks like its 90% trees and 10% fresh water. "Unmix" enough pixels and you can string them together to find streams smaller than 300 m wide that cross an expanse of forest or grass-land. A string of 10% water pixels in a 300 m resolution image is probably a 30 meter-wide stream. Moreover, the plants around water often different substantially from the plants in the drier surrounding areas -- making it even easily to infer the existence of creeks that are far smaller than the resolution limit.
Two wrongs don't make a right, but three lefts do.
US forestlands covered 732 million acres in 1920; today they cover 747 million acres.
A gain of 15 million acres over 85 years.
Roughly 176,471 acres gained a year.
Meanwhile, worldwide, we are losing rainforests to the tune of 1.5 acres per second.
That works out to 47,336,400 acres lost a year...more than 268 times the rate forestlands are growing in the U.S.
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~ |rip/\/\aster /\/\onkey
You got your calculation wrong because you don't get the operating principle of the MERIS instrument. It is not a half megapixel ordinary camera that with some magic collects 15*16 bit per pixel (e.g. by taking 15 images in close succession with a changing filter wheel).
As the page on MERIS says, it is a 'pushbroom imaging spectrometer'. 'Pushbroom' means that instead of a rectangular field of view like a normal camera, it has a line-shaped field of view. An image is formed by continuously observing the single line and wait for the the satellite to 'sweep' the whole planet. 'Imaging spectrograph' means that the previously mentioned line is spectrally separated (with a prism or a grating) perpendicular to the line. You then get an image on your CCD where one direction corresponds to the distance along the line and the other is formed by the different colors.
The optics details of the system are here, an description of the CCD is here. If I understand it correctly, one line is 740 pixels wide and the colors are 'binned' in 15 different spectral bands. That gives you 740*15*2=22200 bytes per line. How much that would be per picture depends on the height of the image, which depends on how long you collect data. In principle you could have it sweep the whole planet non-stop.
karma police: arrest this man, he talks in maths; he buzzes like a fridge, he's like a detuned radio. [radiohead]
That number does not make a distinction between old-growth forest which is bio-diverse and mono-culture treefarms which have very limited habitat for anything but genetically-engineered fast growth pine trees.
Starman97@Gmail.com (bring it on spammers)