Another breakwater for Plymouth

TiggerToo

TiggerToo

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I know this has been shown before here: but why are there two superimposed images of Plymouth's breakwater on Google Earth? Does this happen anywhere else on G/E?

Also why does my car show up in my drive, as do the slabs in my back garden lawn, but not the huge yellow mooring buoys on the Hamoaze/Tamar?
 
They seem to have superimposed two images and not noticed the oddity. A forumite posted a pic of a marina from Google Earth that had two images superimposed. The ghost images of boats that were'nt there at the time of one of the pictures looked as though they had sunk.
 
GE is made up of a series of photos taken from satellite (obvious statement)
These photos are not all taken at the same time (also bleedin obvious)
What is not so obvious until you think about it is that they are not all taken from an identical orbit as the satellites are not geostationary. This means that the positions that the satellites are directly over at the time they take the photo ain't the same in every case. Now we know the earth is a sphere and ain't flat so there is a slight distortion at the edges of any photo taken. GE does it's best to interpolate the photos to show seamless joins, but can't always match up two photos. If one photo was centred on say Truro and another on Exeter, and they both show Plymouth, then they will not show the breakwater in quite the same place, will they? Couple this with the fact that the Truro one may be 2 years old and taken by a completely different satellite to the one taken yesterday of Exeter, and all these satellites are
in slowly decaying orbits so the height may also be a bit different, it's a bleedin miracle they match up at all innit!! Actually if you look carefully at the joins you will see all kinds of missmatches all over the place. Roads don't quite join up, rivers have kinks in em, and in some cases things dissapear completely until a new photo is taken when it pops back. Like half a boat.......
 
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.... it pops back. Like half a boat.......

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So that's what all you mono sailors are doing - waiting for the other half of the boat to appear as if by magic. /forums/images/graemlins/grin.gif
 
Shortly after I launched my boat in 2002 it was on GE in 3 places at once.
1. In my back garden getting built
2. In Chichester harbour on a swinging mooring
3. Half way down the solent under sail!
Now theres only one in Fareham..... good job some will say!
 
Re the quality of the pictures of the lower Tamar on GE, I had always assumed it was downgraded deliberately to hide a lot of the details of the dockyard?
 
I am informed that Google Earth images are taken from satellites down to a certain altitude where they are virtually seamlessly changed to aerial photographs for the 'closeups'. Therefore, as explained above, they were taken at lots of different times.
 
I really don't care about your decaying bottom but the GE images are definitely taken by satellites that were originally put up there for military purposes. What you have generally are obsolete images sanitised to some extent to remove strategically sensitive "targets". There are 2 exceptions to this. The long distance shots of the earth are not in fact from space, but generated by "downscaling" the images. Some (not all) detailed close ups of some areas are indeed from aircraft, but the area covered by these is tiny in comparison with the satellite images.
I suggest you visit a good proctocologist for your other problem.
 
While most world-wide coverage in GE is satellite imagery, in fact the hi-res data for the UK is aerial photography. However, its availability is not uniform, and in low population density regions GE reverts to satellite images. The satellite images are from a wide range of satellites, primarily Landsat (low resolution), and Quickbird (high resolution). The satellites are NOT in the same orbits, but all are in orbits around 700km up. Quickbird uses off-nadir imaging, exaggerating the displacement of elevated objects.

We have provided data for GE, so I am not guessing, I know! And I have been working on satellite remote sensing since the early 80s.
 
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I suggest you visit a good proctocologist for your other problem.

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His posting history makes interesting reading. 4 posts, all confrontational and 3 downright rude.
 
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I know this has been shown before here: but why are there two superimposed images of Plymouth's breakwater on Google Earth? Does this happen anywhere else on G/E?


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If you want to see something really confusing then look at the skyscrapers in Manhattan or Hong Kong...they are wibbly wobbling all over the place /forums/images/graemlins/smile.gif
 
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