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Most Complete Topographical Map of Earth Complete
An anonymous reader writes "Kudos to NASA and the Japanese trade ministry for mapping 99% of the Earth's surface, surpassing their previous effort, with which the new data will be amalgamated. Apparently, the data will be free to download and use."
Apparently, the data will be free to download and use.
You know, it never ceases to amaze me that CNN, BBC, Fox News, everybody who's a major player can't link to the original source of information (and Japan's site). One might find the warehouse inventory search tool (note registration required for ASTER global digital elevation model) interesting to play around with if they are interested in the story.
My work here is dung.
In most of Europe, periods are used as thousands-separators in the same way we Americans use commas.
Le français vous intéresse?
5.100.720 km
To put that in perspective, it's about the size of Australia.
No, but they always try to use a [sup][/sup] tag a on crappy American website ans when the said crappy website refuses, they sigh and give up.
Ezekiel 23:20
Wow. You have the most prescient username in all of Slashdot. Who could have known when UID5s were gettable that "divide by zero" would become memery?
Son, "divide by zero" was a joke/meme before the Internet existed, much less slashdot.
That's not really an issue with this type of data. Remember, the resolution is 30m. There is nothing geologic (that would show up in this type of data) that moves anywhere close to that on human time scales.
There IS data on movement such as those you list, showing real time (in geologic time anyway) movement of the crust due to tectonics, or other things. It's actually a pretty major field in geology, studying minute changes. InSAR and millimeter-accurate differential GPS are two techniques.
Relatively coarse DEM data like ASTER or SRTM is used for different applications where millimeter accuracy isn't necessary - i.e., most things :)
Additionally, there is enough inaccuracy in the instrumentation used for DEM data like this that doing multiple passes will give you significantly different results - the error is measured in meters. Therefore, any small changes - and earthquakes, volcanoes, and tectonic movements are small changes in the big scheme of things - are completely irrelevant as they'll be averaged out anyway. It should be interesting to make a comparison to previous datasets, though, and I'm sure there are people working on that already.
Of course, I suppose you'd notice in this data if a huge volcanic explosion occurred, like when half of Mt. St. Helens blew off. However, that's exceedingly rare :)
IAAGGS (I am a geology grad student).