seer
Master Chronicler
Reged: 12/09/02
Posts: 3107
Loc: Northern California
|
|
Probably the greatest technological advance in Google Earth is the patent pending Network Link(TM) mechanisms described by Google's Keyhole Markup Language(TM) specification. These Network Links allow individuals, businesses, governments, and other organizations to easily publish dynamic geospatial data layers and have them seamlessly integrated into the unified Google Earth environment where it will be seen by millions of users as they search the globe.
The great power is not only in being able to deliver custom dynamic view-specific and time-specific content to individual Google Earth explorers, but further in the fact that users can see many of these layers at the same time. Want see the weather in Chicago? Click on the weather network link, save it to My Places, and enable it. Want to see the Crime in Chicago? Do the same. Want to see the homes for sale? Same again, Now with all thee enabled, just fly through this custom information landscape and pick a safe, home with a great location not far from the river and in the price range. Want to know which of these are open today? Just click the "more" link and the integrated web browser will show you where to go. KML is a sophisticated Service Provider Interface (SPI) that anticipates and provides the context for just this type of personal data fusion.
This forum is the place to share network links so that others may subscribe to the live data feeds they bring to each user's Google Earth environment. Developers using KML are encouraged to visit the KML Support forum for advice and tips then describe their dynamic data service in posts here with descriptions and links back to the supporting websites and/or a downloadable KML network link as appropriate.
We salute the innovation in the results that we have already seen and expect to be awed by those yet to come!
--------------------
Be seeing you,
Seer
|
ink_polaroid
Sysop
Reged: 01/01/05
Posts: 1868
Loc: SF Bay Area, CA
|
|
We also encourage developers to take advantage of the View-Based Refresh ability of our Network Link.
When the view-based refresh is active, the network link will return the coordinates (west, south, east, north) of the user's viewing window to your server. This will allow you to parse the user's location and return KML specific to that user's current view. (For example, if your network link source was a Perl script, a user looking at San Francisco might return something like http://your.server.com/source_file.pl?BBOX=-122.522859,37.721792,,-122.359974,37.813426 . If you have a lot of data spread out over a wide area, it should be obvious how this feature not only allows you to use bandwidth very efficiently, but also allows you to present the user with a clean, dynamic visual experience.
Note also that with careful parsing of the coordinates of the bounding box, it is possible to calculate an approximation of the user's altitude. Several Keyhole users have asked for the ability to simulate the LOD-type display of data (i.e. dynamically displaying more data as the user's viewpoint gets closer to the ground). This is now possible.
The KML tutorial document has some sample PHP code that shows you how to parse the user's location and return a placemark centered in the user's viewing window. That is a very simple application, but already we've seen people using the feature in some very creative ways.
|
James_Macgill
Tourist
Reged: 07/04/05
Posts: 26
Loc: State College, PA, USA
|
|
OK, I've built a reflector that ties KML to existing WMS servers. Its not as nice as haveing GE read capabilities docments directly but it does give us instant access to a LOT more data.
Feel free to add the following URL as a network link. (For best results set view-based refresh to after camera stops)
I can't say that it will remain up forever, especialy if it gets hit a lot!
Also, I'm open to requests for specific WMSs as it is easy to add them just let me now.
http://www.geovista.psu.edu/kml/kml2wms.jsp
|
neo
Tourist
Reged: 05/05/03
Posts: 266
Loc: Geschwenda, Thüringen, Germany
|
|
It works! And it works great! 
I'm impressed.
Well done, James_Macgill!
--------------------
Blue Marble & Red Planet-Explorer (sorry, for bad english - it isn't perfect...not yet ;-)
|
ink_polaroid
Sysop
Reged: 01/01/05
Posts: 1868
Loc: SF Bay Area, CA
|
|
Hey guys,
At the risk of being known as that guy, I want to make a small clarification to what a dynamic data layer is. But perhaps it's easier to say what it is not, so here goes:
It's not an image overlay that doesn't change.
Which is not to say that we don't want to see your overlays. Au contraire, we *demand* that you share them with us. But there are other fora here for them. Several posts I've seen recently in this forum would be much better suited to the Nature and Geography forum, for example.
Basically, this forum is here to allow those of you interested in playing with Network Links and remotely refreshed image overlays to do so. A good rule of thumb is this: if you're not posting a network link to serve up KML from a remote host, or not posting an image overlay that updates itself over time, then this forum probably isn't where you should be posting it.
That aside, there's another, much better, reason to post static overlays elsewhere. If, for example, you post your overlay of geological data in Nature and Geography, then that post will be integrated into the Keyhole Community BBS layer in the client. If you post it in this forum, it might not be.
I'm going to start moving posts to more suitable homes soon. If you've just made one here and are realising that you should have posted elsewhere, don't worry. I'll give enough time for the replies to be posted.
Fair enough? Do I sound too grumpy? Probably just sunstroke. 
|
ErwinNikkels
Tourist
Reged: 06/30/05
Posts: 2
|
|
Hi,
The network link basid GlobeAssistant displays the spots, pictures and a connection to a Weblog on the GoogleEarth Globe. The content from www.GoogleGlobe.com is used. Very cool application with a lot of nice spots.
GlobeAssistant can be activated at http://www.googleglobe.com or downloaded directly at http://www.googleglobe.com/php/files/802.kmz
Enjoy it!
Erwin
|
valtus
Tourist
Reged: 07/26/05
Posts: 74
|
|
It takes me to a location of 0.0, 0.0 for some reason.
I'm pretty sure your message should read "Flying too high" not "Flying to high"
|
barryhunter
Guide
Reged: 07/30/05
Posts: 596
Loc: Wales, Europe
|
|
Quote:
Note also that with careful parsing of the coordinates of the bounding box, it is possible to calculate an approximation of the user's altitude. Several Keyhole users have asked for the ability to simulate the LOD-type display of data (i.e. dynamically displaying more data as the user's viewpoint gets closer to the ground). This is now possible.
Edit: According to this thread this is due in next release, horray!
Theres no way to get an idea of the viewers direction (when at low angles), am I correct in this?
The reason I'm asking is that I have some datasets (see this thread) that have far to many points to download for wide views.
Therefore what I've done is just display 150 random points within the view, this works quite well when the viewpoint is directly overhead. But when going to lower angles, a large proportion of the viewable area is away in the distance. Therefore out of my random markers many are actully quite a distance from the user.
Ideally what I would like is to be able to display more points in the foreground, and less in the background (but maybe still a few to show there are some more 'out there')
I can't see how this is possible with just the BBOX, any other ideas?
Thanks Barry
--------------------
- www.nearby.org.uk - www.geograph.org.uk - www.trigtools.co.uk -
Edited by barryhunter (08/03/05 04:54 PM)
|
TheOneTrueBrad
Tourist
Reged: 09/24/05
Posts: 5
Loc: Monroe, LA
|
|
New guy here. Where do I find the weather network link? Is this something I've got to pay for? Or do I have to download something other than the free version of google earth? I'm not very computer literate.
|
seer
Master Chronicler
Reged: 12/09/02
Posts: 3107
Loc: Northern California
|
|
Brad,
Don't worry about not being 'computer literate' when you have the all important underlying skill of literacy. One great thing about being literate is that you can write to people who can help you, which is what this Community is about.
There are many posts in this form for live weather information. You can search for 'weather' using the Community Search at the top of the page or the Google Search at the bottom. A few examples:
Weather Channel US Weather
Twin Cities Weather RADAR
Many more around the world...
--------------------
Be seeing you,
Seer
|
Previous
Index
Next
Threaded
Edit
Reply
Quote
View in Google Earth