How Google Earth displays dates on their imagery

As you probably know, when you’re looking at an area on Google Earth, the date the imagery was captured appears in the lower-left corner, as shown here:


However, what does that date actually mean? As some of you have pointed out, the date doesn’t always correspond with the imagery (snow on the ground in July, etc).

For standard satellite images, it’s simply the date the imagery was taken, which makes sense. Easy enough. The discrepancies arise when Google loads imagery for a large area from a commercial aerial provider. In those cases, they’re given a range of dates for the imagery. The date you see on the screen is the “oldest known date” for that imagery, while the tic mark in the Historical Imagery sliders is the “newest known date”. In many cases, those date ranges can be up to a few months apart.

To confuse it further, some providers don’t even have exact dates for a batch of imagery; they might simply say “April-June, 2010”. In those cases, Google considers that to be “April 1 – June 30, 2010”, and then displays the date as explained in the previous paragraph.

While the system obviously isn’t perfect, it’s certainly improving. Google Earth didn’t start showing the date in the corner until version 5 came out (so you had less of an idea of when the imagery was captured), and the Historical Imagery tool was certainly a great addition to Google Earth.

As the pace and quantity of imagery updates continue to increase, I expect we’ll see some refinements to this system over the coming years to help it become even more accurate and useful.

New Ground-Level View in Google Earth 6

GEB takes an expert look at the new features in Google Earth 6. We have had a chance to play with some of the powerful new features and content. And we have a few important tips and observations to share.

As you know, Google Earth 6 was just released and has some amazing new features. The major focus of this release is focused on the “Ground-Level View”. As you approach the ground, Google Earth 6 will automatically shift you into Ground-Level mode, which provides a great way for you to browse around while anchored to the ground. (That’s the default behavior anyway – more on this later.)


This enhanced realism (3D trees, better handling of close-up 3D views – first released in 5.2) from the ground-level is a great addition to Google Earth, so Frank and I have been testing the new release. Keep eading for GEB’s observations and tips.