Section: 3.2.3 Plan Views of Gridded Data

3.2.3 Plan Views of Gridded Data

Plan views are horizontal displays of two dimensional data. These data can be true 2D fields (e.g., sea level pressure) or a slice of a 3D dataset at a constant pressure or height (e.g., 500 hPa heights). The IDV can display these plan views as contours, color filled contours, or color shaded displays.

First, let's create a display of contours of sea level pressure.
- If you have not already done so, use the Edit->Remove All Displays menu to remove the displays created in the previous exercise. Set the viewpoint to the top.
- In the Field Selector's Data Sources panel, select the NCEP Model Data ETA data source that you loaded in during the previous exercise.
- In the Fields panel, expand the 2D grid tab. Select the mean sea level pressure (ETA model reduction) field.
- In the Displays panel, select Contour Plan View then click the Create Display button. The data will be read from the remote server and displayed in the main map window of the IDV.
- From the control window for this display, you can change the contour interval. Click the Change button next to the Contour: label to open the Contour Properties Editor. In the editor, change the contour interval to 2 and click the OK button.
Now, let's add a display of color-filled contours of precipitation.
- In the Field Selector's Fields panel, select the total precipitation over accumulation interval field.
- In the Displays panel of the Field Selector, select Color-Filled Contour Plan View and then click the Create Display button.
- Since this is a display of precip over an accumulation interval, there will be no display for the first time period of the model. To see the display for subsequent times, start the animation.
- Stop the animation and return the display back to the first time in the sequence.

Overlay contours of 500 hPa geopotential height on the same display.
- In the Fields panel, expand the 3D grid tab. Select the geopotential height field.
- In the Displays panel, select Contour Plan View.
- In the Data Subset panel, select Level tab and select the 500 hectopascal level then click the Create Display button.
- Start the animation.
- From the control window for this display, change the level to 250 hectopascals using Levels selector.
- Rotate the display to see that the level you selected is displayed above the surface parameters.
- Try other levels and notice how the pattern and position changes.
- Stop the animation and return the display back to the first time in the sequence and reset to the overhead view.

Unidata IDV Workshop for version 3.0u2 > Accessing and Displaying Data > Working with Gridded Data