How much data do different types of imagery need?

This is the second in a series of posts on Google Earth data sizes. Yesterday we had a look at 3D imagery and also compared it to the aerial imagery in the same location. Today we are looking a the different types of 2D imagery. As we have seen in the past, Google Earth has imagery in a wide variety of resolutions.


Just that tiny white square has 1.5 GB of aerial imagery.

We tested using regions of 100 square kilometres with a camera height of 1 km, except for the regions with aerial imagery, where we set the camera hight to 300 m to try and ensure the imagery loaded completely.

Location Imagery type Size in MB
Germany Aerial imagery – Geobasis-DE/BKG 1,532
United Kingdom Aerial imagery – Google 2,002
Japan Aerial imagery – Google 1,930
South Africa Satellite imagery – CNES / Astrum 247
Canada Satellite imagery – DigitalGlobe 368
Algeria Satellite imagery – Cnes / Spot Image 20
Papua New Guinea Satellite imagery – Landsat 16
Pacific Ocean near Hawaii Ocean floor detailed 12
South Atlantic Ocean Ocean floor minimal detail 8
Zoomed out view of Google Earth 3

As you can see, the amount of data used by different imagery types varies dramatically. The ocean floor figures may be a little inaccurate as they include the 3 MB or so that Google Earth downloads just on logging in to show the earth when zoomed out. We initially thought the German aerial imagery was higher resolution than in other parts of the world, but the results suggest that is not the case.

The country of Germany is approximately 350,000 square kilometres. It would take about 525 GB to store all the aerial imagery in the default view for the whole country. Historical imagery adds a whole new dimension, which we will look at in our next post in the series.


Samples from the locations we tested. Note the scale on each image.

To see the locations we tested with in Google Earth, download this KML file.

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.






PLEASE NOTE: Google Earth Blog is no longer writing regular posts. As a result, we are not accepting new comments or questions about Google Earth. If you have a question, use the official Google Earth and Maps Forums or the Google Earth Community Forums.

Comments

  1. ben reuter says

    Whatsoever … it is meaningless if google continues its policy to tune down the supply of new images, what is underway rigth now.

    • Timothy Whitehead says

      I am not sure what you mean as the amount of new imagery that Google adds increases every year.

  2. ben reuter says

    Hi Timothy!
    What I mean is that the frequency of updates is declining. We usually had a major update every month.
    I’m constantly monitoring Russia and Middle east (Syria).
    Many regions which in former times got update lets say every 3 or 4 month at least, are ignored since a long time (e.g. Naval Bases in the Kola Peninsula like Zapadnajy Litsa 69.433028° 32.354294° or the recent developments at the Latakia airport and the Russian build up 35.407554°35.949377°).
    Cheers

    • Timothy Whitehead says

      Syria and Ukraine appear to be censored. See this post for a map of what was updated in 2015:
      https://www.gearthblog.com/blog/archives/2016/01/satellite-imagery-updates-2015.html
      Note that it is not Google that does the censoring but rather governments who go to the satellite imagery providers and ensure that they do not give the imagery to Google – I believe by purchasing rights to all the imagery but I cannot confirm this.
      I do not know if Russian naval bases are censored but it is also possible that whoever was ordering the imagery in the first place has lost interest or it is just because it is winter in the northern hemisphere and not suitable for satellite photography. Remember that for satellite imagery, Google generally does not choose what gets photographed but rather gets imagery that was captured for other reasons – usually of places that other people are interested in. Aerial imagery is different in that Google is now actively capturing large quantities of aerial imagery in a number of locations around the globe, but this is dependant on suitable weather so there is a slow down in winter.

  3. ben reuter says

    Thanks for your response! That might be true. I’m just wondering why other providers do have updates:
    Syria: http://up.picr.de/25126166ct.jpg
    and for example Naval Base at Kamchatka on Terraserver
    http://www.terraserver.com/view.asp?cx=158.493547&cy=52.915538&proj=4326&mpp=0.75&sdrt=jax
    Cheers



PLEASE NOTE: Google Earth Blog is no longer writing regular posts. As a result, we are not accepting new comments or questions about Google Earth. If you have a question, use the official Google Earth and Maps Forums or the Google Earth Community Forums.