Re: Google Earth: Elevation of water?

Bitstring <5956h1571k8ses8edudupnugk41b07fsnt@xxxxxxx>, from the wonderful person Terry Pinnell <terrypinDELETE@xxxxxxxxxxxxxxxxxxx> said 
As I move the hand pointer across a lake, the displayed data for
'Elevation' plainly varies, so I assume it must be the altitude above
sea level of the ground at that point? It plainly cannot be the
surface!

For example, I'm looking at Ardingly Lake ('ardingly, sussex, uk').
Other mapping programs I use such as Memory Map etc, tell me its
altitude is 174 ft, yet GE shows wide variations throughout.


'Wide' being ??

Yet, inconsistently, the English Channel is correctly shown as 0 ft
throughout, as is the Atlantic Ocean (give or take a foot or two).

Anyone know what's going on here please?

Well if GE is using the NASA SRTM data then it is often well flaky over water - height variations of +/- 10m are common, and +/- 25m not unheard of, what with tides, storm surges, wind waves, etc.

Some major water bodies have been cleaned up by many people, based on 'well, it has to be zero outside the coastline, dunnit, stupid!' algorithms, but I doubt that has been rigorously applied to all the inland lakes and seas.

--
GSV   Three Minds in a Can
Contact recommends the use of Firefox; SC recommends it at gunpoint.
.

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