Sunday, June 18, 2006

Google Earth -- World Wind -- ArcExplorer

I was recently at an Air Force conference where Google Earth, NASA’s World Wind, and ESRI’s ArcExplorer where prominently displayed. The serious interest that organizations like the Air Force are putting into these platforms has given me the opportunity to explore each of these platforms a bit more in depth.

I am still using Google Earth a great deal. I don’t believe that it can currently be challenged in its ease of use and clean navigation. My 5 year old loves to play with Google Earth, and has no trouble getting around the planet to points of interest. Their KML data representation and the use of Network links to serve data offer a very interesting and open way to create very unique customizations. For organizations with a very large amount of data, it is tough to beat their server products. This would work very well for the Air Force, which could leverage their own imagery holdings with other services and NGA to create their own world for Air Force specific applications and visualizations.

Things I wish they would do …. Currently, Google Earth offers a couple of methods to integrate existing GIS data into their system. You can load KML files, or you can purchase their Fusion product that compiles your data into a format that can be hosted by their Earth Server product into a Google Earth Enterprise Client (the Google Earth Browser with extended features). You have two options with the Earth Server. You can either have a hybrid system in which you load your vector data into the Earth Server and view it against the Keyhole server imagery. Or you can get Enterprise Pro, and host ALL of the data in your own world.

The whole Google Earth product line is really an enterprise system. It works best when everything is put together. I would like to see what I would term an organizational level system (as opposed to enterprise). An example would be using a Windows 2003 Server to host organizational data (to include imagery) that can be securely fused with the larger Keyhole imagery server. The great majority of organizations don’t want to just load their vector data in the big Linux based Google Earth Server in a hybrid mode, or be responsible for populating an entire world if they have localized imagery. They want to view their holdings fused against the Google data.

Secondly, if the Google Earth Client could expose some additional capabilities to developers in their API, the GIS community could rapidly start tacking on some pretty sophisticated geoprocessing capabilities.

I finally got around to downloading the World Wind source code, and started investigating their method for creating Plugins. I have seen World Wind improve quite a bit over the last year. And believe that it will continue to get better. Its unique power in this game is that it is open source and license free. They automatically provide the ability to completely customize the user interface and provide the ability for any developer to integrate any type of GIS data. I am currently working on an extension that uses Yahoos geocoding service to search for locations and zoom to them in WW.

I have only seen ESRI’s ArcExplorer in Beta. I will withhold my comments on it until it is released. It will probably work very well for anyone who already has an investment in an ESRI based system. I am looking forward to doing some development work with it before the end of the year.


  1. Anonymous5:57 AM

    Why on Earth would you want to lock up all your imagery into a google format and shun standards??

    World Wind can access WMS just fine. The data stays in a format that is not locked away.

    BTW.. World Wind already uses the Yahoo finder. Click on placefinder and see for yourself.

    But don't go throwing money away.

  2. For large organizations, server space is cheap, but capability is priceless. Having static data stored in multiple formats is a small price to pay for the flexibility that may be provided. Standards are vital, but do not solve all problems.

    The Google Earth EC will also consume WMS, and many people have created ArcIMS based network links that provide access to WMS. ArcExplorer will have similar capabilities.

    I have looked at the Place Finder extension in World Wind. I think it is great. My plan is to use this as a target solution as I figure out how World Wind Works. I would also like to see if I can decouple my interface so that it can be used in other applications such as ESRI, MapWindow, and other GIS systems. Once I get better at World Wind, I’ll move on to data manipulation.

    I have no money to throw away. Only time.