Pfeil GECalc - a geocomputation tool for Google Earth


Pfeil Idea: Google Inc. indented that the software Google Earth is used as a Geo-Browser. So Google Earth (GE) is a powerful tool searching Objects which are related to the earth. The main task for GE is to visualize Objects on the earth. Therefore GE doesn’t provide specific geo-computation functionality. Only basic calculations, like distance measurement, related to the visualization are provided.
Pfeil During this project the Authors try to show how geo-computation can be combined with the powerful visualization functionality of GE. This is done by an example application using Google Earth API and communicating with GE. Google provides a COM API (is in beta phase) which allows third party applications to query information form and send commands to GE. Through IApplicationGE, applications can query for example the current viewport, control the 3D viewpoint, use KML features, and more. The example application called GEcalc will perform some basic geo mathematical operations. The results of the operations will be displayed on GE via using the COM API. The data for calculation and visualisation is stored in KML files. The Authors focus on point data and implement a buffer function. E.g. A set of points is given via a KML files. Based on this data and the input parameters of the buffer a result set of the points is visualized.
Pfeil Screenshoots: Sampleimage #1 | Sampleimage #2 | Sampleimage #3 | Sampleimage #4
Pfeil Data used and needed for the projects are ordinary KML files containing a set of points. No other specific data is needed. Methods for the example application are the buffer operation, where based on a buffer point and a given radius, all data points inside the buffer area are selected.
Pfeil Questions that will be answered are:
  • Is it possible to use Google Earth for geo-computation tasks?
  • How can Google Earth be used to visualize results of geo-computation?
  • Where are the obstacles or bottlenecks using the Google Earth COM API
  • Which advantages will there be to use such an approach?
The result of the project is an example application GEcalc providing a buffer operation. The result of this buffer operation will be displayed on GE or optionally stored as a KML file. It should also be possible easily to extend the Application with other mathematical functions like overlay reclassification and others, or to make even more complicated mathematical models.

Pfeil Download
Pfeil Application: GECalc Application pic (Download the zip file pic and unpack it on your hard drive. Then you should be able to start pic GeoCalc.exe. Tested on Windows XP and Windows Vista. You need to have Google Earth 4.0 or higher installed on your computer.)
Pfeil Version: The current version is 0.1 beta. The functionallity contains Buffencalculation and Altitude Query. Please help to make the application better.
Pfeil Presentation: GECalc Presentation pic
Pfeil Info: A short presentation about the introducation of GECalc.