The Google Earth Network Link

One of the most powerful features within Google Earth is the feature called the network link. The network link enables someone to tap into information in another file somewhere either on your local machine, or on a computer somewhere else on the Internet. The information can basically be anything the Google Earth files (KML files) can support. For example: Placemarks, lines, polygons, image overlays, and even 3D models. Network links also enable you to better handle KML files and keep the time it takes to start up Google Earth faster.
A network link simply points to another KML file somewhere. That file can be generated by a program running on another computer. The network link can automatically refresh based on a setting within the network link. You can update as fast as once a second, or just have it update once. You can also update network links based on when the user moves their view in Google Earth (this is called View Based Refresh).
Let me illustrate the power of the network link with some examples:

  • Global Cloud Map – this network link lets you automatically view a composite of satellite photos of the Earth’s clouds overlayed on the Earth. Not only that, but it automatically shows you the latest composite from a server which updates every 3 hours. If you store this network link in your My Places, every time you turn it on it will automatically have the latest photo (you must have an Internet connection obviously).

  • USGS Earthquake Monitoring – This network link automatically shows you the most current seismic activity – and summarizes activity during the last week with greater than magnitude 1.0. Read more about it here. Notice that the network link includes placemarks, lines, and a legend. Anything you can put in a KML file can be in a network link. This network link automatically updates (or refreshes) every 5 minutes.

  • 3DWarehouse Network Link – This network link both presents to you the latest locations of 3D models at the Google 3DWarehouse, and also uses the feature of view based refresh. Depending on where you look, it will present you more information at that location. If you are zoomed further out it will show you a summary of models in different areas of your view. Zoom in closer and it will show you individual placemarks for each model in your view (if there are any). Read more about the 3DWarehouse network link here.

Besides providing the powerful ability to provide you with current and dynamic information, the network link can help you manage your Google Earth data much more efficiently. If you save a lot of your favorite KML files in your My Places it can slow down how fast Google Earth starts. This is because all the files in your My Places have to be loaded when you start. You can still keep pointers to all your favorite files, but keep the file size much smaller by using the network link. First, save each of your favorite KML content from your My Places to a file on your local machine, or, better yet, find the URL of the original file on the Internet. Then create a network link (menu “Add->Network link…“), and either put the local file location or the URL of the KML file in the Link field. Give the network link an appropriate name and description. Before you exit Google Earth, decide whether you want the network link turned on or not. Your My Places will now only be a couple hundred bytes for each network link and will only load more information if you leave it turned on the next time you start Google Earth. You can also have network links load other network links to reduce the size of your My Places even more. But, I’ll save tips on doing that for a future post.
More reading on the network link:

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Comments

  1. Tim Froehlich says:

    I just redownloaded and saved the cloud cover map but I noticed that it made it hard to see anything that actually had clouds over it. So what I did was I expanded the network folder and opened the properties on the layer, the one with the two light blue overlapping rectangles icon. I went to altitude, and set the altitude of the layer to normal cloud height, around 5000 meters. Now when I zoom in far enough, I don’t need to disable the layer to be able to see anything.

  2. Tim, for an even better way to do the cloud map, check out my Blue Marble 2.0 Add-on which both gives you global clouds that disappear as you zoom in, and gives you a better satellite composite of the Earth from NASA’s Blue Marble collection (which also fades away as you get close). Here’s the add-on write-up:
    http://www.gearthblog.com/blog/archives/2006/11/new_blue_marble_addo.html

  3. Dear Frank,
    I try to add “network link” in a “KMZ”, but I really dont know how to do it. could you please kindky do me a favor to illustrate that? bye the way, the “network link” I like to add is my Picasa web albums. the purpos is to share a small size “KMZ” file via email to my friends. I dont like the “KMZ” file include any pictures except some thumbneils. please do help, thanks…

  4. bart barbour says:

    Can some one tell me how to save “my places” so that I can take the files to another computer, like in a classroom, and get it to work? I have several “tours” saved in my places, and I cannot use them in the class since they do not seem to be readily copied. PLEASE HELP!!!
    Thanks,
    Bart

  5. bart barbour says:

    Can some one tell me how to save “my places” so that I can take the files to another computer, like in a classroom, and get it to work? I have several “tours” saved in my places, and I cannot use them in the class since they do not seem to be readily copied. PLEASE HELP!!!
    Thanks,
    Bart

  6. Hélio says:

    I need to format my HD. What can I do to save all my favorite mark places, like home, school… and then, move the saved marks to the new installed version of the Google Earth?
    Thanks for the attention.

  7. Ronaldo Richers says:

    how to save “my places” so that I can take the files to another computer,

  8. right click => Save as… => *.kmz – file

  9. ok, so is it possible to set up a network link that can be viewed on multiple computers that are on the same network?

  10. “ok, so is it possible to set up a network link that can be viewed on multiple computers that are on the same network?”
    lauren, you will need to have the file in a network share folder. If you have any folder on your network that every computer/user can go to and open the folder -> that is where you want to store your .kml / .kmz file and set the Network Link to the file in the network share folder.

  11. Terry Reed says:

    I need an application that will produce a map route between a taxicab and a customer. Of course, the customer will be at a fixed location. The driver’s data will be constantly updating. Probably gps/agps. We need the application to generate a routed map between the taxicab driver and the customer. That route would then be sent to the taxicab driver and the customer along with the trip information. Can anyone help? Any suggestions?

  12. Is it possible to have NetworkLinks share the same sessionID?

  13. TonyTampa says:

    I’m trying to figure out how to do a Network Link (Dynamic KML). Do I have to add anything to the KML, or do I just park the file? I’m lost. Sorry

  14. How can I transfer all of my placemarks to another computer?

  15. Im having problems and lost allot of work by trying to save files ive made as a kml and then adding as a network link, but after adding some custom icons, saving and closing, it doesnt even pick up the network link after reopening the GE… please help me someone its driving me mad !?

  16. I added a network link to a file on my computer’s hard drive and it worked, I was able to view the points in Google Earth. When, however, I added a link to a file on our server, it did not work. The link name appears in the table of contents on the left, but I am not able to see it in Google Earth. I am also not able to view the properties of the file, such as to change opacity, scale of the label etc. I am able to do all of this when adding a network link to a local file, however.
    Advice appreciated.

  17. oh, i appear to have fixed it. It needs to be a non UNC path… don’t start it with \\server\folder name\blah\blah.kml, start it with a mapped drive eg D:\folder\blah\blah.kml. weird

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