Dubai impound ships suspected in cable damage

Alexander Harrowell a.harrowell at gmail.com
Sun Apr 13 11:47:43 UTC 2008


Lots - for values of lots including "practically all" - of ships use the AIS
(Automatic Identification System), which broadcasts various details on
radio. For an example application, try www.aisliverpool.org.uk

On Fri, Apr 11, 2008 at 6:44 AM, <Valdis.Kletnieks at vt.edu> wrote:

> On Tue, 08 Apr 2008 22:16:57 PDT, Joel Jaeggli said:
>
> > spot can generally deliver an image within 1 day in 60kmx60km blocks
> > assuming no contention for the slot. 20m resolution is more than
> > adequate to pick up ships underway at sea. ikonos can deliver 11x11km
> > swaths.
>
> And ikonos can do a lot better than 20m resolution.  We had ikonos target
> the campus for a special event a few months ago:
>
> http://glovis.geog.vt.edu/hokiesthanktheworld/
>
> "The full extent of the satellite image is approximately 100-square
> kilometers,
> stretching from Brush Mountain (upper left) across Blacksburg (center) to
> Ellett Valley (lower right). The Virginia Tech Drillfield is located near
> the
> center of this November 17, 2007 scene from the GeoEye IKONOS satellite.
> This
> true color rendering by Peter Sforza combines red, green, and blue
> wavelengths
> (3.7-meter pixels) into a RGB color image, and sharpened using the
> panchromatic
> band (0.92-meter pixels). Note the sun's angle of elevation was 32 degrees
> and
> the azimuth was 164.1 degrees (north being zero)."
>
> 1-meter pixels sounds about right - if you look at the right place on the
> full-scale image, you can find (and tell the difference between) my dark
> green
> Camry, and the immediately adjacent dark grey Nissan my neighbor drives,
> and
> still see 3 feet worth of parking lot pavement in between them too...
>
> Not bad for 423 miles up and moving at 4.7 miles per second....
>
>
>
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