出国网考研英语频道为大家提供2015考研英语题源阅读:Satellite imagery,大家可以阅读一下!小编提醒大家要多阅读,考试阅读的速度才会快!
2015考研英语题源阅读:Satellite imagery
FOR an industry that lurked in shadows for decades, satellite imaging’s transition into the mainstream has been dramatic. Such imagery is worth billions of dollars each year to governments and private industry. Imagery on demand—from a specified locale in near-real time—is still of enormous strategic value to spooks. But it has, in the years since satellites have shed their inaccessible-spy-technology image, also become an approach that lends itself to humanitarian, environmental and educational projects. Now Skybox, a recently acquired division of Google, is joining such efforts by promising free imagery for categories of work it deems "for good”.
There are a few factors that affect the ultimate value of satellite images, including the resolution (the fineness of the detail evident in the photographs), and how recently or how often the images can be acquired—that is, the degree to which the satellite’s view is a real-time picture of what is happening on the ground. The highest-resolution satellites are still the stuff of spy agencies. Lower-value, outdated imagery is available to the average consumer in the form of services such as Google Earth.
But that leaves quite a bit in the middle. The American government, for example, releases a stream of lower-resolution, specialised satellite photography at no cost. Such images may be used for broad purposes, such as tracking long-term trends in the amount of land under cultivation or forest cover. What is of more use is specifying what is to be imaged and where, and Skybox is not the first company to promise such a thing on apro bono basis. DigitalGlobe, the dominant American image provider (which recently began operating the highest-resolution satellite in commercial hands), has had a foundation in place since 2007 to release its data for academic projects. Mark Brender, the foundation’s director, says that 700 such grants have been made. He cites the Harvard Signal programme, a project at that university which checked the veracity of 2,000 published reports of conflict in Sudan in 2011 and 2012 against satellite imagery of 40,000 square km, captured over the same period.
The offer from Skybox is a compelling one, not least because it will aim to image most of the planet, every day. That should be possible once its constellation of 24 satellites is in place; three are already in orbit and it has an ambitious schedule to launch the rest. The Skybox For Good effort is backed by Google's long-standing interest in both philanthropy and the free sharing of information on its for-profit side. Skybox won't limit itself to academic projects, and aims in its initial projects to help with, for example, tracking disaster recovery and documenting the ebb and flow of refugees in conflict zones.
Unlike the DigitalGlobe Foundation, which places usage restrictions on the imagery it provides, Skybox releases its data under a Creative Commons copyright. That means that any re-use—including for commercial purposes—is permitted, so long as the source is attributed. Some images are already available, neatly plotted in Google Maps. There are ever more eyes in the skies, but with them increasingly comes the promise that those who need to can get a look.
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