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I see from various online sources (including GIS.SE's own How to download the entire ASTER GDEMv2 dataset?) that the ASTER GDEM has 22'000 tiles, each 1°×1° and 3601×3601 pixels (each pixel being 16-bit integer), with both elevation and quality rasters.

A handy napkin says the uncompressed data would be 22000 * 3601 * 3601 * 2 * 2 / 1024**3, or ~1063 GB. But how big is the compressed data that you download from the official providers?

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Ahmed Fasih
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I have downloaded nearly 21000 ASTGTM2 zip files and they take about 250 GB disk space.

Detlev
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  • How long did that take? – Ahmed Fasih Nov 30 '15 at 02:09
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    @AhmedFasih I cannot state exactly anymore what time it takes to download this set, maybe 2 weeks. The bottleneck is the ordering procedure, because you must go through interactively. Once ordered and confirmed, it is possible to download in a batch job at night. This (at least 2012) the quota for a single order at http://gdem.ersdac.jspacesystems.or.jp/index.jsp was higher than at http://reverb.echo.nasa.gov/reverb/ I prefered to went through the procedure of the first server. As with all downloads it depends on your bandwidth, the max transfer rate of the server, and so on. – Detlev Nov 30 '15 at 09:26