[OSM-talk] OT - Unusual Bing imagery

[andrzej zaborowski]

On 24 July 2012 03:48, Alan Mintz <Alan_Mintz+OSM en earthlink.net> wrote:
> At 2012-07-23 16:02, andrzej zaborowski wrote:
>> The area in the screenshot seems to have a higher resolution than
>> satellites can achieve.
>
>
> Is this documented somewhere? Assuming from the look and ratio of
> measurements of the jet that it is a B737, the pic is at z20 (~12cm/pel @
> middle lats). I was under the impression that all of the Bing/Yahoo/Google
> imagery was still satellite-based, down to z21 (6cm/pel). I know Google has
> spots of "UHR" imagery at z22, but it seems they were still referred to as
> satellite. I've seen individual county websites with very nice imagery
> described as "flyover", as though coming from airplane/helicopter,
> apparently on a contract basis.

I've assumed 0.5m/px is the technical limit for satellite imaging,
Wikipedia seems to confirm this more or less:
"The latest commercial satellite (GeoEye 1) has a GSD of 0.41 m
(effectively 0.5 m due to United States Government restrictions on
civilian imaging)."[1] I guess military satellites might have better
parameters, but anything you're likely to see on the web with a higher
resolution will be taken from within the troposphere.

I've been told once that 0.5m is the usual limit around the world
except Israel of which you're unlikely to see imagery better than 2m
due to the government's threats.

Cheers