Using External Volumetric Data in STK Tutorial

STK Pro, STK Premium (Air), STK Premium (Space), or STK Enterprise
You can obtain the necessary licenses for this tutorial by contacting AGI Support at support@agi.com or 1-800-924-7244.

When bringing Volumetric data into STK, at least two altitude values must exist in the data.

Capabilities covered

This lesson covers the following STK Capabilities:

  • Analysis Workbench
  • Coverage

Problem statement

Given an HDF5 file containing latitude, longitude, altitude, corresponding temperature data, and a variety of volumetric object properties, you will use the file as a means of displaying temperature data over time as a 3D graphical overlay in STK.

Solution

Given a set of volumetric data properly formatted for use in STK, you will manually import the HDF5 file into STK, configure the object properties for the volumetric object, and view the data as displayed over time in the 3D Graphics Window. Take the following short steps to complete this:

  • Load the HDF5 file into a volumetric object in STK.
  • Set appropriate scenario and graphical properties.
  • Animate the scenario.

For this tutorial, you will use an HDF5 (.h5) file that you converted Using MATLAB to Convert Volumetric Data from CSV to HDF5 File (.h5) or an HDF5 file from the STK install. The Help topic Using MATLAB to Convert Volumetric Data from CSV to HDF5 File (.h5) shows how to convert large data files to the HDF5 file type as well as properly format object properties within the HDF5 file.

When bringing Volumetric data into STK, at least two altitude values must exist in the data.

Loading your data to STK

Now that you have your HDF5 file properly created with your weather and volumetric object data, you can import it into STK for volumetric analysis.

  1. Launch STK.
  2. Create a new scenario named VolumetricWeatherData.
  3. Set the Start time to 11 May 2015 16:00:00.000 UTCG and the Stop time to 13 May 2015 16:00:00.000 UTCG.
  4. Click OK to create your scenario.
  5. Open the scenario properties and go to the Units page.
  6. Using the drop-down menu, change the CurrentUnit type for Temperature to Celsius (degC) and click OK.
  7. Open the Insert Default Objects drop-down and double-click Volumetric to create a new Volumetric object. Rename this object to VolumetricWeather.
  8. Open the VolumetricWeather object properties and select the Load Grid and Computed Data check boxes.
  9. Click the ellipses button (.…), go to the HDF5 file created using the Using MATLAB to Convert Volumetric Data from .csv to HDF5 File (.h5). If you did not create a file using the conversion process, you can use my_volumetricExampleScenarioDynamicWeatherData.vmc.h5 file located in <STK install folder>\Data\Resources\stktraining\samples.

Change graphical properties for 3D dynamic visuals of weather data

With your HDF5 file properly loaded, you can now change some of the graphical properties of the volumetric object to properly display your data.

  1. Open the VolumetricWeather properties and go to the 3D Graphics-->Attributes page.
  2. Select the Smoothing and Shading check boxes and ensure Quality is set to High.
  3. Open the Grid page and clear the Show Grid check box.
  4. Open the Volume page and select the Spatial Calculation Levels check box. Clear the "Immediately update graphics" check box.
  5. At the lower section of the Volume page, under Show Active/Inactive Fill, click the drop-down next to Value and choose degC.
  6. At the bottom of the Volume page, click Insert Evenly Space Values….
  7. In the Insert Evenly Spaced Values dialog box, change the Start Value to -18.15, the Stop Value to 16.85, and the Step Size to 5. Under Ramp Colors, change the Start to Blue and the Stop to Red. Click Create Values.
  8. Inside the Fill Levels box, you should see eight evenly spaced values with correspondingly graded colors. Under the % column, which denotes the value’s translucency level, change the values to the ones shown below.

    9.  

    Value (C) Translucency %
    -18.15 10
    -13.15 25
    -8.15 60
    -3.15 57
    1.85 55
    6.85 35
    11.85 35
    16.85 48

     

  9. Go to the 3D Graphics Legends page and select the Show Legend check box. Change the Title to Temperature (C).
  10. Click Apply and then click OK.

What you should see now is your weather data displayed in very effectively expressive 3D Graphics.

Animating your dynamic data

With your data finally loaded into STK on a volumetric object, and the graphics now properly displayed, you can animate your scenario to exhibit the data as it changes over time.

  1. Open your VolumetricWeatherData scenario properties.
  2. Go to the Basic-->Time page and select the Stop at Time check box.
  3. Change the Step Size to 1200 seconds and click OK.
  4. Right-click the VolumetricWeather volumetric object and click Zoom To. Orient your camera view normal to the projected area.
  5. Press the animation Start button.

As you can see, the data displayed changes over time. The graphics of the Volumetric object should now convey what looks like actual changing temperature patterns as they move across the continent.

Try moving the camera around so that it looks at the southern edge of the volume, as shown below.

Notice the pronounced temperature difference between altitudes of the volume. Try moving around the camera to look at and animate the underside of the volume.

There are several demonstrative and explanatory graphical attributes you can change for volumetric objects, including the Grid, different Volume Boundary and Fill Level gradient scales, and Cross Sections. Explore some of these properties to better understand their uses.