• What is Google Earth ?

• What do we do ?

• Processing

• Applications, Tools and Freeware

Google Earth is a three dimensional visualizing interface used for quick and easy data publication. It combines the ingenuity of Google search with satellite imagery, maps, terrain, 3 dimensional environments and much more making the world's geographic information available to everyone. The concept behind it consists of a 3 dimensional blank sphere superimposed by satellite imagery and additional data. A full description of this application is available on the official Google Earth website at www.earth.google.com. Futhermore, a free version of Google Earth is available in the download section of their official website; this free version is the minimal requirement to view the samples posted on this page.

We provide the means to publicize scientific data on Google Earth in order for the user to visualize and analyze the data both in space and time. This 4 dimensional system gives the user the ability to view North American Regional Reanalysis (NARR) data, 3-D bar graphs of various variables, vector data as well as animations in their appropriate spatial and temporal reference. We are presently working with various tools in order to view the following data on Google Earth:

NARR Data as image overlays (georeferenced raster images with appropriate scale reference and with or without temporal associations) Sample (1) : NARR Temperature Data (uncompress and open the kml file NARR Temperature Data with Google Earth)

Bar Graphs of meteorological data as 3-D models (georeferenced and with or without temporal associations) Sample: 3-D Precipitation and Mean Temperature data

Vector Data as a combination of placemarks, paths and polygons (georeferenced) Sample: ada_boundary

Point form meteorological data as a placemark (georeferenced with or without temporal associations) Sample: Weather Stations

Time dependant Animations of NARR variables as image overlays (georeferenced with optional date and time reference) Sample: Animated NARR Temperature data (2) (date and time reference is not associated with this sample; an instructional readme file is also provided in the EarthAnimator file)

(1) Samples can be viewed using the free version of Google Earth since they are available in KML (Keyhole Markup language) format.

(2) The following tool is necessary to view the animation; Google Earth Animator. To run the animation, unzip NARR Temperature Data, import NARR_TEMP_Data.gif into Google Earth Animator, the time interval must be set to 1 second, save single frame must be enabled and the destination file path must be assigned to any desired path and filename. The user must then open NARR_TEMP_Data.kml in google earth, go to properties and finally set the link to the filename in the destination file path assigned in the previous step.

Google Earth was conceptualized in a certain way so that the user could quickly and easily view their data on its interface. In order to satisfy these requirements, the language used to define and customize the visual features had to be simple and practical. Hence, the various aspects of the publicized data are coded in the Keyhole Markup Language, KML. To learn more about KML visit the appropriate user guide section. In the case of an image overlay, such as NARR Temperature Data, a KML file (tab-based ASCII or text file) refers to the image using a simple path tab to the appropriate directory where it is stored. In order to create the NARR Temperature image we are developing a MATLAB script, which will convert the original Grided Binary format of the NARR data into a raster image. The image can then be geographically referenced using one of two methods; direct georeference through GRB2KML script (temporarily only for Equidistant Cylindrical lat/lon data) or using an intermediate georeferencing freeware called LibGeoTIFF and Google Earth PRO. The following are tutorials, which are meant to walk the user through and explain the various steps involved in the processing and publication of different types of data on Google Earth:

• NARR Data on Google Earth
  (subject to change with the development of GRB2KML script; Flash reader is required)
• Weather Stations on Google Earth
  (Not yet available)
• 3-D Georeferenced Bar Graphs of Meteorological variables on Google Earth
  (Not yet Available)
• NARR Temperature Data Animation with associated date and time reference
  (Not yet available)
• NARR Temperature Data Animation without associated date and time reference
  (Not yet available)

An additional help tool is the Google Earth user guide. Further information and advice on Google Earth can be found in the Google Earth Community. For up-to-date news on features and applications of Google Earth visit the Google Earth Blog. The following PowerPoint presentation include extra information on possible processing options of different data types into KML format to be viewed on Google Earth; DAI on Google Earth Summary; NARR and Shapefile Processes and Package. A detailed description of GE-Graphs and additional help files for the application in question are available here.

In order to create and publicize data on Google Earth in specific formats, the following programs, tools and freeware are required:

• MATLAB - Processing NARR climate and meteorological data as image overlays requires MATLAB to run the GRB2KML and scripts
• LibGeoTIFF - Georeferencing of a NARR image created with MATLAB and GRB2KML scripts requires the LibGeoTIFF freeware
• CSV2KML - Batch generation of placemarks on Google Earth such as the Weather Stations sample requires the CSV2KML freeware package
• GE-Graphs - Generating 3-D Georeferenced Bar Graphs of Meteorological variables on Google Earth requires the GE-Graphs freeware and a simple text editor.
• Freeware animation package - Generating NARR Temperature Data Animation without associated date and time reference requires MATLAB and the freeware animation package
• GRB2KM - Generating NARR Temperature Data Animation with associated Date and time reference requires MATLAB and the GRB2KML scripts (Not yet Available)