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Table of Contents for GEON IDV web site Introducing the GEON IDV GEON IDV Displays, and Data from UNAVCO and GEON Download & Run the GEON IDV Tutorial ... How to Use the GEON IDV ... More Tips Data Formats: How to Put Your Data in the IDV

GEON IDV Tutorial

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Part 3 - CREATING DISPLAYS

After adding a data source, the Dashboard shows the "Field Selector" panel.  In it you will see, in the
left "Data Sources" panel, the data sets you connected to.

     Setting Projection (map area) and Vertical Scale

You only need to do this once to work with data in an area.

You need to set the IDV's "Projection" - the map view to show the data in. 
Click on the main menu choice "Projections" and check OFF the item "Reset Projection with New Data," if it is on. 

Choose the main menu choice "Projections -> Set -> Yellowstone Park." 
The view in your display changes. The IDV has preset projections and can make new ones of any kind by hand, or from a data set.

If you do not see state boundary maps, click on "Displays -> Maps and Backgrounds -> Add System maps -> North & Central America."

Set the vertical scaling for the 3D display. Choose, on the display menu, the menu choice 
"View -> Viewpoints -> Vertical Scale." In the window that
appears, enter "Min value:" -25.0, "Max value:" 5.0, and for "Units" choose "km" (kilometer). Click the "OK" button.

To move the map's level to the Earth's surface, in the Dashboard click the Display Controls tab. In there, click the Displays tab;
then move the "Map position" slider to 1/6 of the way down from "Top."

Choose the main menu choice "View -> Show" and check "Show wireframe box" if it is not checked already.
(If you want to see a little 3D action, do a right-mouse-button press and drag over the display now.)

To save all this work so far, for future runs of the IDV (including restarting today if necessary), make the main menu choice
"File -> Default Bundle -> Save." "Bundles" are IDV configuration files; the IDV starts with the "Default Bundle."


     To make displays

To make a data display, in the Dashboard's Field Selector panel, click on the "YNP_locations_mags_2000..." data source. 
In the "Fields" 
panel is "Point Data" the kind of data this is (data at scattered locations, not a grid for example). In the "Displays" panel is 
"Point data plot" which is what we want. Click on the "Create Display" button under the panels.

Some earthquake locations appear in the display as crosses. 

In the Dashboard, the Fields window is automatically replaced with "Display control" window for this display.
If you see no location points marked,  the display control, click on the "Station Model" selector box and choose "Locations 3D cross."

To see the locations in 3D, do a right-mouse-button press and drag over the display.

Here is what you are seeing:

Make a display with the "YNP_GPS_..." data source the same way. First change the Dashboard back to the the Field Selector. 
This time set "Station model" to be "GPS Vectors."

Make a display with the "YNP_eq_loc_mag_focmech_73-97.nc" data source. This time the "Station Model is "Focal mechanisms, full sphere."

Click in the main window Displays list on the item with Station Model locations as 3D cross. 
The display controls for point data allow you to declutter the number of points shown, or show all the data, and change
plot symbols with the "Station Model" selection box. For example earthquakes may be show as simple locations, or colored by data value (magnitude).


    Rotation and Zooming

Put the mouse pointer in the display. Hold down the right mouse button and slowly drag the mouse a little. You will see
the 3D display rotate into view, something like this:

Your instructor will show the many ways to zoom, pan, and rotate. Or you can read about it in the GEON IDV how-to page at

How to Zoom pan and rotate

Zoom pan and rotate can be achieved with mouse and keyboard actions, and menu buttons.

If your display orientation is confusing, click Control - r to reset to the overhead view.


    The Displays List

In the right side of the main window is the "Displays" list. Click on the blue name of each display to bring forward the display
window for each display. Check off the check box to the left of each name to hide a display (but not to remove it). To remove 
a display, click on the trash can icon to the far right of the display name. Don't remove any displays yet.  In 
actual use do remove displays you no longer need. They can hold on to
a lot of computer memory better used otherwise.


    3D Topography Relief 

Let's make a 3D relief map of topography around Yellowstone.  In the Dashboard's "Field Selector":
click on the data source file "YNP_GTNP_topography...."   "Altitude" should appear in the "Fields" panel.
In the Dashboard "Displays" panel click on the blue "3D Surface" button,  and then click "Topography" under that. 
Click on the "Create Display" button below. A color 3D relief map should appear in the display.

Rotate (drag right mouse button over the display) to see the 3D effect. Note that most of the earthquakes are hidden under the surface.
Rotate the display to see under the surface. But some earthquakes but some are clearly visible above the surface, 
indicating incorrect depth estimates. The GEON IDV is an excellent and fast way to review data quality, and see details.

Note in the main window "Displays" list a color bar appeared under the new display's name, which shows the color table that 
associates colors with data values, in this case with elevation values. There are many IDV choices and controls for color tables.
Do a right click on the color bar to see a menu that accesses color table controls. We will not use any color table controls yet.

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