STEM to GoogleEarth View
The STEM to GoogleEarth view projects the results of the STEM
simulation onto GoogleEarths 3D display of the World. For example, in
the following display, the progress of a disease is shown in red
superimposed on the GoogleEarth display.
Color Key
- Blue - Susceptible
- Yellow - Exposed
- Red - Infectious
- Green - Recovered
Prerequisites
You must have installed the GoogleEarth application which is
available for personal use from the GoogleEarth download
site. You should verify that GoogleEarth works correctly on your machine
by starting it and verifing that you can browse the 3D image.
Plus it is a fun application to play with. Note that some older
computers do not have the 3D graphics capabilities required by
GoogleEarth and you will not be able to run GoogleEarth.
Starting the STEM to GoogleEarth interface.
You can leave GoogleEarth running or not. STEM will start it if
needed.
If you are running STEM from the source distribution, you need build the
Servlets as described later.
- Startup the STEM application as described earlier.
- Load GoogleEarth View Windows->GoogleEarth View
- Select the GoogleEarth View from the Tabbed Window.
This should start the GoogleEarth application if it was not
already started. The STEM-GoogleEarth interface has many options that
can be set from Windows->preferences->STEM->GoogleEarth However,
we can use the defaults for our first run.
- Start a new simulation by selecting the Scenario window.
- Select the USA scenario. STEM->Geography->Political->Country->USA
- double clicking the "Spanish Flu" Scenario.
- After the display has run for at laeast 7 cycles,
press the pause control.
- Select the GoogleEarth View and press the Display button.
- You should see the current state of the Spanish Flu infection superimposed on
the GoogleEarth map.
Manual mode versus Automatic Mode.
The STEM to GoogleEarth is distributed with the default to run in Manual mode.
In order to see the state of the disease superimposed on the
GoogleEarth 3D image, you have to manually press the display button.
The more interesting way to run it is with the GoogleEarth display
being automatically updated on each cycle with the current status of the disease.
But because both STEM and GoogleEarth use a lot of CPU resources and
system memory, they will only run well simultaneously if you have at least
two Gigabytes of memory and a fast processor. It will run with one gigabyte
of memory but very slowly.
If you are lucky enough to have 2 Gigabytes memory, go to the
GoogleEarth Preferences
and set the "method" preference to "Asynch Servlet" or "Direct Launch".
The next time you start a simulation, you should then see the disease spread
in the GoogleEarth window as STEM runs.
You can also right click in the STEM-GoogleEarth window to bring up
a context menu with additional commands.
Building Servlets
If you are running from the STEM source distribution:
- Update STEM to the latest code level and ensure it is refreshed and rebuilt.
- From project org.eclipse.ohf.stem.ui.ge select servlet.xml
- Select RunAs->AntBuild
- From Eclipse, Run Stem using stem.product in org.eclipse.ohf.stem.ui
as described earlier
If you are running the STEM standalone executable, the above steps were
already done for you and you just need to start STEM.exe.