Sunday, February 26, 2006

Google Earth as My Ubiquitous GIS Interface

I have been working with Geographic Information Systems (GIS) for over 10 years, and have spent the last six working primarily with the DoD (mostly the Air Force). I started off creating geospatial strategic plans for 13 Air Force Base Civil Engineer organizations and a Marine Corps Base in early 2000. That is the year that I also started honing my skills on becoming a more skilled GIS programmer, initially starting with VB 6 and ArcObjects, and then moving on to .NET. In April of 2003, I took a job with CH2M HILL, and started working on-site at the US Air Force Academy in Colorado Springs helping them implement the US Air Force GeoBase Program.

I have had quite a bit of experience with the organizational aspects of GIS, and have struggled to make it relevant to as many people as possible. This has not always been easy. The simple fact is that the great majority of geospatial users in an organization (such as an Air Force installation) need nothing more than a good visualization of their area of interest. This has not always been the strong suite of many GIS packages. I needed something that was simpler and more intuitive than the web-base GIS systems we had typically been deploying.

GIS is used extensively at the Academy. In fact, virtually every cadet there has ESRI’s ArcEditor loaded on their Government issued laptop, and the cadets are required to take introductory GIS courses that become more advanced as they pursue their major.

GIS Day has become a rather large event at the Academy, and is well attended by a number of vendors. One of the vendors that was in attendance on GIS Day 2003 was the Federal Sales representative for Keyhole (now known as Google Earth). The Keyhole demonstration was by far the most popular demonstration for the cadets, as they lined up to plug their address into the Keyhole client and zoom to their homes.

The next year, the same Keyhole representative was in attendance. I had planned to ask more about importing GIS data into the client, but most of the talk centered on Google’s purchase of Keyhole.

This set the stage for 2005. By this time, I had become very interested in open source geospatial capabilities. It started when a colleague of mine asked me to look at JUMP GIS. At that time, I had no idea on the depth of open source capabilities that were out there. The more research I did on the topic of open source GIS, the more excited I became.

This interest coincided with the release of Google Maps, which was followed closely by the free release of the newly christened Google Earth (GE). This, of course, was followed closely by Yahoo Maps and Microsoft’s Virtual Earth. I was, and continue to be, truly amazed by the visualization capabilities that these products provide.

I was also jealous that my ArcIMS and ArcSDE/Oracle system could not operate as smoothly and efficiently as the Google products. Now granted, these are not GIS products, and only have a fraction the power that is available with ArcGIS (I won’t be giving it up anytime soon), but they made me think about my constant wish to have a very simple and pleasing interface for all of the people I wished to serve maps to. If only I could get my data into Google Earth.

In September 2005, while having lunch in downtown Colorado Springs with a number of people from our local CH2M HILL office, I started talking about Google Earth with one of our Enterprise Spatial Solutions Vice Presidents. As our conversation worked its way towards the many ways that Google Earth could help the Air Force mission, he commented “you know that Google Earth has its own language don’t you? It’s called KML, for Keyhole Markup Language.”

I had not known that.

That evening, I downloaded the KML Tutorial off of the Google Earth Forum website.

The next day, I created my first point, line, and polygon in the free version of Google Earth using KML.

The day after that, I started to frantically write ArcObjects code to export the Academy’s building feature class into 3D buildings in Google Earth.

By the end of October, I had a full blown ArcObjects extension with a suite of tools that dynamically convert any ESRI based vector data set to its KML equivalent. I also had started creating Google Earth applications with the Google Earth API using .NET and JavaScript.

One of these applications demonstrates the capability that this technology offers the Air Force, and has been used to brief close to 30 General Officers and the Under-Secretary of the Air Force. I also had (what I consider to be) the unique honor of showing this same application to Google Earth’s General Manager, Strategic Sales Manager, and Chief Engineer at the Google Headquarters in Mountain View, CA in November 2005.

By Christmas, I had started developing plans for creating a license free KML creator. I selected an open source GIS, and wrote an extension to convert shapefiles into KML. I have been very pleased with this experience, and am now interested in creating a complete geospatial visualization system solution using Open Source GIS and Google Earth as the use interface.

As it stands, I believe that I have found the user interface that I have wanted for so long. I also feel that 2005 changed a lot of things in the geospatial world, and I am more than a little bit excited about the way that new and more freely accessible technology is allowing us to view information using our planet as the interface.

One interesting thing that happened during my Google Earth research was that I stumbled on to the concept of BLOGs. There are several very good ones dealing with Google Earth, and I have used them all. I have no intention of trying to replicate them. My primary interest is to talk about methods to make Google Earth more relevant to individuals and business who want to see their own personal data displayed in a way that makes sense to them.

I should have started this BLOG last June. Since I did not, I anticipate that it will take me a while to figure out how to use this effectively. I hope that I’ll eventually publish something here that will be helpful to someone.

Well … here it goes.


  1. Hi Tim,

    I've been using gis for a long time as well, though not as a programmer. I love a lot of what GE has done to make geographic visualisation actually *fun* and rapidly accessible. I've also dreamed about using it is a universal gis data viewer within our department (about 200 users).

    Unfortunately though the license get's in the way. It's only available for *personal* and *individual* use. This restriction also applies to the Plus and Pro versions. :(

    I've called and written to Google on several occasions asking for clarification on their license policies but have yet to recieve an answer.

    Something else that might work is the open source NASA World Wind. In general usage it is quite similar to GE. It's chief advantage, from my standpoint, is the ability to provide local caches of the data. So it could be used on a disconnected laptop in the field for instance.

    Another entry in the field which is new to me and I haven't had a chance to investigate much yet is EarthSLOT/Terra Explorer.

  2. ...forgot to say that with World Wind you can also get at (and change) the underlying elevation data which is a big hole in KML and GE.

  3. Thanks Matt,

    You make a very important point about Google Earth’s current licensing limitations. I also wish that they could provide some additional insight on what they consider to be permissible.

    It is also probably important to point out the NASA’s World Wind application is truly open source software. Google Earth does not actually fall into that category.

    I’ll be very anxious to see how World Wind develops over time.