Observations about the 2016 ‘historical imagery’ updates

Earlier this week we released maps showing the imagery updates of 2016 according to the ‘historical imagery’ layer. The maps were created using the Google Earth Plugin/API, which Google has since shut down. It was scheduled to be shut down on January 11th. It was still working yesterday, January 12th, but is not today, January 13th.

Southern Hemisphere
The first thing to note about the maps of ‘historical imagery’ is that there is no imagery in the southern Hemisphere from July onwards. This is not because Google is not adding fresh imagery there, but because it only updated the ‘historical imagery’ layer for the Northern Hemisphere. During the first half of 2016, Google was updating ‘historical imagery’ almost weekly, but in mid-July they stopped and didn’t update it again until late December, but apparently only updated the Northern Hemisphere. They have been doing imagery updates for the Southern Hemisphere, but they can only be seen in the default layer.

Types of imagery
Google gathers aerial imagery for some parts of the world. We believe it collects the imagery itself as the imagery shows no attributions other than Google. There is also this page suggesting it sells aerial imagery, too. Aerial imagery can typically be identified by the size of the imagery patches. They tend to be large rectangles as opposed to the smaller rectangles or strips of satellite imagery. Aerial imagery is used almost exclusively for:

  • The continental United States.
  • Western Europe, excluding the Scandinavian countries.
  • Japan.

A few countries have received a mix of both satellite and aerial imagery:

  • Ireland
  • New Zealand
  • Australia.

If you see Google aerial imagery from 2016 anywhere else, please let us know in the comments.

Satellite imagery all seems to come from two suppliers, DigitalGlobe and CNES/Astrum.

Reasons for imagery
Aerial imagery, especially in the US, appears to be gathered on a schedule, with the US being covered approximately once every three years. Satellite imagery appears to be gathered for three basic reasons:

  1. To capture particular events. DigitalGlobe’s ‘FirstLook’ program gathers imagery of natural disasters, man-made disasters, political instability and human interest. See the FirstLook map to get an idea of what is covered. Most FirstLook imagery eventually makes its way into Google Earth. We have covered a number of these locations in previous posts. Imagery gathered for particular events tends to be of poorer quality, sometimes being black and white or false colour and having a high percentage of cloud cover.
  2. Particular locations of interest to the suppliers DigitalGlobe and CNES Astrum. This is especially noticeable with DigitalGlobe imagery, which is gathered very regularly for certain locations, usually cities.
  3. Random locations where the imagery suppliers managed to get good quality imagery because weather conditions were just right.

We do not know whether or not Google ever makes special orders for satellite imagery or what their agreements are with the satellite imagery suppliers.

Weather
Weather plays an important role in the gathering of imagery. Google avoids snow cover and cloud cover where possible, both of which are quite seasonal. This results in a curious pattern of imagery gathering, which you can see in this map.

Population
Sparsely populated areas such as mountains and deserts typically get a lot less imagery than highly populated areas.

Censorship
Iraq, Afghanistan, Syria and the Ukraine are censored and got no updated imagery during 2016. We do not know how the censorship is achieved, but it is most likely not up to Google. Our guess is that the satellite imagery providers have been paid to not supply imagery to Google for those countries. Imagery is being gathered, and it would appear that you can buy imagery for those countries via TerraServer and other suppliers.


India and Pakistan got good coverage for 2016.

About Timothy Whitehead

Timothy has been using Google Earth since 2004 when it was still called Keyhole before it was renamed Google Earth in 2005 and has been a huge fan ever since. He is a programmer working for Red Wing Aerobatx and lives in Cape Town, South Africa.



Comments

  1. this has become messy to be honest, updates in southern hemisphere in 2016 are sometimes in historical update and sometimes can only be viewed without it. it’s becoming hard work

  2. One recent historical imagery update that really bothers me is the old Landsat imagery being everywhere, that is, down in every zoom level. You can be zoomed in close to maybe a 500m swath of terrain, hit “Historical Imagery”, and in the timeline get all the Landsat updates down to 1984, so the vast majority of the local historical imagery obviously will be very low resolution and completely useless right there with the eye that close to the ground.

  3. Google is a company without direction or leadership which is why they make great products but fail to do anything useful with them that will truly revolutionize anything.

    Google or should I say Alphabet is just ran by stock brokers who only care about stock news and if they are going to have to downgrade from 5 mansions to 4 due to a deal that went wrong. I mean the pains of losing your status is quite the hardship and stress.

    It’s such a tough choice to choose between selling one of your expensive Pontiac vehicles or one of your mansions to make up for the deal brokerage gone bad. They are literally starving in the streets like the record label industry for having to make those choices.

    (Note I am dripping with sarcasm for those of you who keep on apologizing for these greedy snobs in case you haven’t figured it out assuming you even got this far) 🙂

    At least recently all the bugs and glitches due to useless changes are annoyances rather then life threatening situations that we can all just laugh at and give bad reviews.

    When self driving cars and air delivery becomes mainstream it’s going to be a different picture and there is no way they can do the self driving unless they make car insurance so high that it’s impossible to have so people will be FORCED to use Google cars ONLY or go to prison.

    Then you got a huge police state which the google cars will have a *kill switch* if they feel you are going against the system too much and threaten them with truth.

  4. Just noted that this has been fixed (Germany).

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