Part 9: Introduction to the AzEl Mask Tool and Volumetrics

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

The results of the tutorial may vary depending on the user settings and data enabled (online operations, terrain server, dynamic Earth data, etc.). It is acceptable to have different results.

Capabilities covered

This lesson covers the following STK Capabilities:

  • STK Pro
  • Analysis Workbench
  • Coverage

Problem

Engineers and operators require a quick way to determine if the Earth, local terrain, nature and man-made structures affect visibility between ground sites and satellites for a variety of purposes such as communications, imaging, radar and general situational awareness. A country's space program is planning to install a satellite tracking radar in an area that has distant hills and a large mountain range. A communication antenna enclosed by a large radome will be constructed close by. Engineers want to determine how much impact the Earth, terrain and the radome will have on the radar's field of view.

Solution

Using STK, insert Facility objects which will simulate the radar and communication sites. Use a local terrain file for analysis and determine access times between the radar field of view and five earth observation satellites. Use the AzEl Mask Tool to determine if the communication site's radome further degrades the radar's access times to the satellites. Insert an Area Target object to outline the approximate maximum distance that a satellite can be observed by the radar site. Apply the Analysis Workbench's Spatial Analysis Tool to build a constrained grid to determine how much of the radar's field of view is blocked by the Earth, terrain and the radome at a selected distance and altitudes.

What you will learn

Upon completion of this tutorial, you will understand the following:

  • The AzEl Mask Tool
  • The Analysis Workbench Spatial Analysis Tool
  • The Analysis Workbench Time Tool
  • The Volumetric object

Video guidance

Watch the following video. Then follow the steps below, which incorporate the systems and missions you work on (sample inputs provided).

Creating a new scenario

Create a new scenario.

  1. Launch STK ().
  2. Click Create a Scenario in the Welcome to STK dialog box.
  3. Enter the following in the STK: New Scenario Wizard:
    4. Option Value
    Name: AzElMask_Volumetrics
    Location: Default
    Start: 15 Mar 2024 12:00:00.000 UTCG
    Stop: 16 Mar 2024 12:00:00.000 UTCG
  4. Click OK when you finish.
  5. Click Save () when the scenario loads. A folder with the same name as your scenario is created for you in the location specified above.
  6. Verify the scenario name and location.
  7. Click Save.

Save () often!

Turning off terrain server

A local analytical terrain file will be used in this analysis. Disable the Terrain Server.

  1. Right click on AzElMask_Volumetrics's () in the Object Browser.
  2. Select Properties ().
  3. Select the Basic - Terrain page.
  4. Clear the Use terrain server for analysis check box.
  5. Click OK to accept the change and close the Properties Browser.

Adding analytical and visual terrain

An STK Terrain File (pdtt) located in the STK install area will be used for analysis and situational awareness in the 3D Graphics window.

  1. Bring the 3D Graphics window to the front.
  2. Click Globe Manager (Globe Manager button) in the 3D Graphic window toolbar.
  3. Click Add Terrain/Imagery () on the Globe Manager toolbar when Globe Manager opens.
  4. Select Add Terrain/Imagery... () in the shortcut menu.
  5. Click the Path: ellipsis () in the Globe Manager: Open Terrain and Imagery Data dialog box.
  6. Navigate to <STK Install Folder>\Data\Resources\stktraining\imagery (e.g. This PC then C:\Program Files\AGI\STK 12\Data\Resources\stktraining\imagery) in the Browse For Folder dialog box.
  7. Click OK.
  8. Select RaistingStation.pdtt.
  9. Click Add .
  10. Click Yes to enable terrain for analysis in the Use Terrain for Analysis prompt.

Decluttering 3D Graphics window labels

Label Declutter is used to separate the labels on objects that are in close proximity for better identification in small areas.

  1. Bring the 3D Graphics window to the front.
  2. Click Properties () in the 3D Windows toolbar.
  3. Select the Details page.
  4. Select the Enable check box in the Label Declutter frame.
  5. Click OK.

Inserting the radar site

Use a Facility object as the radar site location.

  1. Bring the Insert STK Objects Tool () to the front.
  2. Select Facility () in the Select An Object To Be Inserted: list.
  3. Select Insert Default () in the Select A Method: list.
  4. Click Insert...
  5. Right click on the Facility1 () in the Object Browser.
  6. Select Rename in the shortcut menu.
  7. Rename the Facility1 () to Radar_Site.

Moving the radar site to its location

The radar site is located in Germany.

  1. Open Radar_Site's () properties ().
  2. Select the Basic - Position page.
  3. Set the following:
    4. Option Value
    Latitude: 47.8996 deg
    Longitude: 11.1142 deg
  4. Click Apply.

Defining an Azimuth-Elevation Mask

Define an Azimuth -Elevation Mask (AzEl Mask) to use local terrain analytically. The AzEl Mask constraint leverages a provided or computed AzEl Mask to determine visibility.

  1. Select the Basic - AzElMask page.
  2. Set the following:
    3. Option Value
    Use: Terrain Data
    Use Mask for Access Constraint on
  3. Click OK .

Using a Sensor Object to Define the Radar's Field of View

Use a Sensor object to simulate the radar system's field of view (FOV).

  1. Insert a Sensor () object using the Insert Default () method.
  2. Select Radar_Site () in the Select Object dialog box.
  3. Click OK.
  4. Rename the Sensor1 () to Radar_FOV.

Creating the radar field of view

Use a Complex Conic sensor pattern. Complex Conic sensor patterns are defined by the inner and outer half angles and minimum and maximum clock angles of the sensor's cone.

  1. Open Radar_FOV's () properties ().
  2. Select the Basic - Definition page.
  3. Open the Sensor Type: shortcut menu.
  4. Select Complex Conic.
  5. Enter 180 deg in the Outer: field in the Half Angles frame.
  6. Click Apply.

    7. By setting the Half Angles - Outer: value to 180 deg (vertical angle) and leaving the default Clock Angles values (horizontal angle), you've created a 360 degree FOV.

Raising the antenna's field of view

The radar's antenna is positioned twenty (20) feet above the ground's surface. Sensor Location properties enable you to position a sensor with respect to its parent object. A Facility object's positive (+) Z body points to the center of the earth. If you want to move the Sensor object up, you have to use a negative (-) Z value.

  1. Select the Basic - Location page.
  2. Open the Location Type: shortcut menu.
  3. Select Fixed.
  4. Enter -20 ft in the Z: field in the Fixed Location frame.
  5. Click Apply.

Using the AzEl mask constraint

A Sensor object can use its parent object's AzEl Mask.

  1. Select the Constraints - Basic page.
  2. Select the Use check box in the Az-El Mask frame.
  3. Click Apply.

Visualizing the terrain constraint

2D Projection Graphics for sensors control the display of sensor projection graphics in the 2D and 3D Graphics windows. In order to visualize the constraints that the Sensor object is using, you have to define which constraints can be used to modify the field of view of the sensor.

  1. Select the 2D Graphics - Projection page.
  2. Select Use Constraints in the Field of View frame.
  3. Select AzElMask in the list.
  4. Click Apply.

3D Graphics Projection Properties

3D Graphics Properties for Sensors - Projection is used to control the display of a sensor's cone into space as well as the sensor's extension into space. Extension distances define the length of a sensor's projection. For a constant space projection, enter the projection length in the Space Projection field. In this case, the distance is computed so that the projection of the outermost point on the contour along the bore sight is equal to the distance entered. This is a visualization property, not an analytical property.

  1. Select the 3D Graphics - Projection page.
  2. Enter 50 km in the Space Projection field in the Extension Distances frame.
  3. Click OK.

Viewing the radar antenna's field of view

You are using a Sensor object to visualize the projected field of view of a radar antenna.

  1. Bring the 3D Graphics window to the front.
  2. Click Home View () in the 3D Graphics toolbar.
  3. Change you view so that you can see Radar_FOV's () field of view.

    4. Sensor Field of View

    Your image might look different from the image in this tutorial. You can orient the 3D Graphics window to obtain the same view but it's not required.

    If you were only using the Line of Sight constraint, the sensor field of view would be round. In this instance, you are taking into account the central body (Earth) and terrain which is causing the blockage of the sensor's field of view.

Inserting Satellites

The radar site's primary purpose is to track three (3) Technology Development satellites.

  1. Insert a Satellite () object using the From Standard Object Database () method.
  2. Set the following in the Standard Object Database tool:
    3. Option Value
    Owner: Germany
    Mission: Technology Development
    Operational Status: Operational
  3. Click Search.
  4. Select MAROC-TUBSAT, BeeSat and DLR-Tubsat in the Results: list.
  5. Click Insert.
  6. Click Close to exit the Standard Object Database tool after the satellites are propagated.

Determining Access

Determine the total time each satellite appears within the sensor's field of view. That is considered access time. You will use this value as a benchmark to see if the radome affects accesses to the satellites.

  1. Right click on Radar_FOV () in the Object Browser.
  2. Select Access... () in the shortcut menu.
  3. Select all three Satellite () objects in the Associated Objects list when the Access Tool opens.
  4. Click .
  5. Click Access... in the Reports frame.
  6. Scroll to the bottom of the report.
  7. Note the Total Duration value in the Global Statistics section (e.g. ~ 15137 seconds).

Saving access report as an external text file

Save the access report outside of STK. This is a safe way to retain the original analysis values.

  1. Return to the access report.
  2. Click Save as text () in the Access report toolbar.
  3. Ensure your scenario folder displays in the in Address bar in the Save Report dialog box.
  4. Type Sensor to Satellites Terrain Only in the File name: field.
  5. Click Save.
  6. Close the access report.
  7. Close the Access Tool.

Inserting Communication Site Radome

Construction crews will build a large communication site radome less than one half a kilometer from the proposed radar site. Use a Facility object as the radar site location.

In this scenario, you're using a Facility object to simulate the communication site's radome. If you were actually performing this analysis against an actual building, you would need to consider creating your own 3D model built to specifications. For information pertaining to this subject, start at the Help page: 3D Graphics Properties for STK Objects - Model.

  1. Insert a Facility () object using the Insert Default () method.
  2. Rename Facility2 () to Comm_Radome.
  3. Open Comm_Radome's () properties ().
  4. Select the Basic - Position page.
  5. Set the following:
    6. Option Value
    Latitude: 47.899 deg
    Longitude: 11.1113 deg
  6. Click OK.

Viewing the Communication Radome

View the radome in the 3D Graphics window.

  1. Bring the 3D Graphics window to the front.
  2. Right click on Comm_Radome () in the Object Browser.
  3. Select Zoom To.
  4. Change your view so that you can see the communication site radome and the and radar site.
  5. Use your mouse to set the view so that you can see how Radar_FOV's () projection cuts through Comm_Radome's () 3D Model.

    6.  

    Sensor Field of View Passing Through 3D Graphics Model

    If you look closely, you can see that the sensor's projection cuts through the communication site's radome. The Facility object's 3D Graphics model is not being used as an obstruction during analysis. In order to use the Facility object's 3D graphics model as an obstruction, you use the AzEl Mask tool.

Opening the AzEl Mask Tool

Use the AzEl Mask tool to create a body masking file (.bmsk) that can be used in access computations and visualization. The static body masking files (.bmsk) that are created are used to restrict visibility to a sensor.

  1. Maximize your 3D Graphics window.
  2. Select Radar_FOV () in the Object Browser.
  3. Open the Sensor menu item at the top of STK.
  4. Select AzEl Mask... in the shortcut menu.

    5. The Az/El Mask View window allows you to see the obscuring objects in the six views used in generating the contours. The views will be shown in successive fashion when the Compute button is clicked.

    The AzEl Mask dialog box enables you to identify obscuring objects and define the instant in time at which obscuration contours are computed.

Preparing the AzEl Mask Tool

Start by setting up the AzEl Mask Tool prior to creating a .bmsk file. Set Comm_Radome () as the obscuring object and the window dimension to 500.

  1. Move the AzEl Mask dialog box (AzElMask for Radar_FOV) to the right so that it isn't on top of the Az/El Mask View window.
  2. Select Comm_Radome () in the AzEl Mask window's Obscuring Objects list.
  3. Set the Window Dim: value to 500 in the Data frame.
  4. Click Apply.

    5. Larger window sizes produce more accurate masks which require more access computation time. A mask file cannot be generated if the window dimensions are too small or larger than the STK workspace. If the Dim: value of 500 places this window outside of your STK workspace, decrease the value until it's inside the STK workspace.

  5. Click Compute...
  6. Ensure your .bmsk file (use the default file name) is being saved in your scenario folder in the Select Body Mask File dialog box.
  7. Click Save.
  8. Close the AzEl Mask window and the Az/El Mask View window when the computation is complete.

Constraining the sensor with the AzEl Mask

You can use the body mask file (.bmsk) as a Sensor object's access constraint.

  1. Open Radar_FOV's () properties ().
  2. Select the Basic - Sensor AzEl Mask page.
  3. Open the Use: shortcut menu.
  4. Select MaskFile.
  5. Click the Mask File: ellipsis ().
  6. Browse to your scenario folder if required when the Select File dialog box opens.
  7. Select Radar_FOV.bmsk in the list.
  8. Click Open.
  9. Select Use Mask for Access Constraint.
  10. Click Apply.

Visualizing the sensor AzEl Mask constraint

In order to visualize the Sensor AzEl Mask constraint, follow the same procedure as you did to visualize the terrain Az-El Mask.

  1. Select the 2D Graphics - Projection page.
  2. Leave AzElMask selected in the Field of View - Use Constraints frame.
  3. Scroll down the Field of View - Use Constraints list until you locate SensorAzElMask.
  4. Press Ctrl on your keyboard and select SensorAzElMask.
  5. Click OK.

Viewing the sensor AzEl Mask constraint in the 3D Graphics window

You can view the constraint in the 3D Graphics window.

  1. Bring the 3D Graphics window to the front.
  2. Zoom To Radar_Site ().
  3. Change your view so that you can see Radar_Site (), Comm_Radome (), and Radar_FOV's () field of view being affected by Comm_Radome ().

Sensor Blocked by The Radome

Determining Access

Determine the total time each satellite appears within the sensor's field of view.

  1. Right click on Radar_FOV () in the Object Browser.
  2. Select Access... () in the shortcut menu.
  3. Select all three Satellite () objects in the Access Tool's Associated Objects list.
  4. Click Access... in the Reports frame.
  5. Scroll to the bottom of the report.
  6. Note the Total Duration value in the Global Statistics section (e.g. ~ 15027 seconds).

Comparing data

Compare access data between the access using terrain and the access using terrain and a .bmsk file. The best result would be that you don't lose any access duration.

  1. Open Windows File Explorer ().
  2. Browse to your scenario folder (e.g. C:\Users\username\Documents\STK 12\AzElMask_Volumetrics).
  3. Open the Sensor to Satellites Terrain Only.txt file.
  4. Return to STK.
  5. Compare the Global Statistics Total Duration time in the text file to the Total Duration time in the Access Report.

    • Did the communication site radome affect your total duration access time?

  6. Close both reports and the Access Tool when finished.
  7. Open the Analysis menu.
  8. Select Remove All Accesses.

Analyzing the radar field of view

Based on the curvature of the Earth and that both satellites being tracked by the radar are in a low Earth orbit (LEO), you want to determine how much of the radar's field of view is blocked by the Earth, terrain and the radome in a 360 degree circle using a radius of 3000 kilometers from the radar site. A 3D volume of space will be analyzed inside the sphere between 10 to 700 kilometers in altitude. In order to determine how much the radar field of view is affected, you will use an Area Target object, a Volumetric object, and the Analysis Workbench Spatial Analysis Tool.

Inserting an Area Target

Insert an Area Target () to model the 300 km circle on the ground.

  1. Insert an Area Target () object using the Area Target Wizard () method.
  2. Set the following in the Area Target Wizard ():
    3. Option Value
    Name: OpsArea
    Area Type: Ellipse
    Semi-Major Axis: 3000 km
    Semi-Minor Axis: 3000 km
    Centroid: 47.8996 deg (Latitude)
    Centroid: 11.1142 deg (Longitude)
  3. Click OK.

Viewing the Area Target Object in the 3D Graphics window

View the Area Target in the 3D Graphics window.

  1. Bring the 3D Graphics window to the front.
  2. Click Home View ().
  3. Move your view so that you can see OpsArea ().

3D Graphics Window View of the Area Target

Opening the Analysis Workbench Time Tool

There is no need to calculate the radar field of view for the entire analysis period of 24 hours. You can use the Analysis Workbench Time tool to create a one (1) second interval. You will use this interval when analyzing the radar's field of view.

  1. Right click on AzElMask_Volumetrics () in the Object Browser.
  2. Select Analysis Workbench... () in the shortcut menu.
  3. Select the Time tab when the Analysis Workbench opens.
  4. Ensure AzElMask_Volumetrics () is selected in the Object list on the left.

Creating a Fixed Time Interval

You want a time interval of one (1) second.

  1. Click Create New Interval ().
  2. Click Select... for Type: when the Add Time Component dialog box opens.
  3. Select Fixed Interval () in the Select Component Type list when the Select Component Dialog box opens.
  4. Click OK to close the Select Component Dialog box.
  5. Type One_Second in the Name: field when you return to the Add Time Component dialog box.
  6. Enter 15 Mar 2024 12:00:01.000 UTCG in the Stop Time: field.
  7. Click OK .

Creating the Spatial Analysis Reference Grid Component

The Anslysis Workbench's Spatial Analysis tool enables you to create calculations and conditions that depend on locations in 3D space which are, in turn, provided by user-definable volume grids. You need to create two (2) grids: a Cartographic grid and a Constrained grid. The reference grid will be used to create a 3D volume of space encompassing the Area Target object's sphere between 10 to 700 kilometers in altitude.

  1. Select the Spatial Analysis tab at the top of the Analysis Workbench.
  2. Select OpsArea () in the object list.
  3. Click Create New Volume Grid ().
  4. Ensure the Type: is Cartographic in the Add Spatial Analysis Component dialog box.

    5. A Cartographic grid uses latitude, longitude and altitude based on a central body reference ellipsoid.

  5. Type Ref_Grid in the Name: field.
  6. Look at the following check boxes:

    • Automatically fit to Area Target is enabled: attaches the center of the grid to the Area Target's centroid.

    • Constrain active grid points within Area Target is enabled: tells STK to analyze the grid points contained inside the Area Target, not the overflow points outside the Area Target.

  7. Click Set Grid Values...
  8. Set the following in the Altitude frame when the Grid Values dialog box opens:
    9. Option Value
    Minimum: 10 km
    Maximum: 700 km
    Number of Steps: 20

    The number of steps determines how many grid points are added to the volume for computation and analysis.

  9. Click OK to close the Grid Values dialog box.
  10. Click OK to close the Add Spatial Analysis Component dialog box.

Creating the Spatial Analysis Constrained Grid Component

A constrained volume grid is one in which the grid points from the reference grid are available only when the spatial condition is satisfied.

  1. Select OpsArea () in the Object list.
  2. Click Create New Volume Grid ().
  3. Click Select... for Type: when the Add Spatial Analysis Component dialog box opens.
  4. Select Constrained () in the Select Component Type list when the Select Component Type dialog box opens.
  5. Click OK to close the Select Component Type dialog box.
  6. Type OpsArea_Constrained in the Name: field when you return to the Add Spatial Analysis Component dialog box.

Selecting the Reference Grid

Select the Ref-Grid () created previously as the Reference Grid.

  1. Click the Reference Grid: ellipsis ().
  2. Select OpsArea () in the Object list when the Select Reference Volume Grid dialog box opens.
  3. Select Ref_Grid () in the Volume Grids for: OpsArea list.
  4. Click OK to close the Select Reference Volume Grid dialog box.

Setting the Spatial Condition

Select the Radar_FOV's () Visibility as the Spatial Condition.

  1. Click the Spatial Condition: ellipsis () when you return to the Select Reference Spatial Condition dialog box.
  2. Select Radar_FOV () in the object list when the Select Reference Spatial Condition dialog box opens.
  3. Select Visibility () in the Spatial Conditions for: Radar_FOV list.

    4. This will apply the constrained visibility of Radar_FOV () to the 3D volume grid.

  4. Click OK to close the Select Reference Spatial Condition dialog box.
  5. Click OK to close the Add Spatial Analysis Component dialog box.
  6. Click Close to close the Analysis Workbench.

Inserting Volumetrics Object

The Volumetric object defines a 3-dimensional grid of points using various coordinate definitions, with respect to various reference coordinate systems from the Vector Geometry tool. It also defines the conditions and calculations that depend on locations in 3D space and evaluates these conditions and calculations across grid points.

  1. Insert a Volumetric () object using the Insert Default () method.

Defining the Volume grid

The default volume grid encircles the Earth up to an altitude of 1000 kilometers. Change it to the constrained grid.

  1. Open the Volumetric1's () properties ().
  2. Select the Basic - Definition page.
  3. Click the Volume Grid: ellipsis ().
  4. Select OpsArea () in the Object list when the Select Volume Grid for Volumetric1 dialog box opens.
  5. Select OpsArea_Constrained () in the Volume Grids for: OpsArea list.
  6. Click OK to close the Select Volume Grid for Volumetric1 dialog box.
  7. Click Apply.

Selecting the Spatial Calculation

A Spatial Calculation is a scalar calculation that depends on both time and location.

  1. Select the Spatial Calculation: check box.
  2. Click the Spatial Calculation: ellipsis ().
  3. Select OpsArea () in the Object list when the Select Spatial Calculation for Volumetric1 dialog box opens.
  4. Select Altitude () in the Spatial Calculations for: OpsArea list.
  5. Click OK to close the Select Spatial Calculation for Volumetric1 dialog box.
  6. Click Apply.

Volumetric Basic Interval

Apply the one second time interval created in the Analysis Workbench Time Tool.

  1. Select the Basic - Interval page.
  2. Click the Analysis Interval: ellipsis ().
  3. Select AzElMask_Volumetrics () in the object list when the Select Interval or List dialog box opens.
  4. Select One_Second () in the Components for: AzElMask_Volumetrics list.
  5. Click OK to close the Select Interval or List dialog box.
  6. Click Apply.

Computing Visibility Inside the Grid

The best case scenario would have 100 percent visibility inside the grid. However, the curvature of the Earth, terrain, and the radome will reduce this percentage.

  1. Click Save ().
  2. Select Volumetric1 () in the Object Browser.
  3. Open the Volumetric shortcut menu.
  4. Select Compute.

Generating a report

Generate a report that shows how much of the radar's field of view is visible.

  1. Right click on Volumetric1 () in the Object Browser.
  2. Select Report & Graph Manager... () in the shortcut menu.
  3. Select the Satisfaction Volume () report in the Installed Styles list when the Report & Graph Manager opens.
  4. Click Generate....

    5. You can see in the report that the radar field of view's percent satisfied is approximately 44 percent. Remember, you computed this starting at a low altitude of only 10 kilometers. There will be more losses at lower altitudes due to the central body (Earth), terrain and the radome.

  5. Close the Satisfaction Volume report and the Report & Graph Manager when finished.

Displaying Visibility Inside the Grid

The Volumetric 3D Graphics Grid page is used to define the 3D Graphics Volumetric grid properties for the Volumetric Definition.

  1. Return to Volumetric1's () properties.
  2. Select the 3D Graphics - Grid page.
  3. Clear the Show Grid check box.

    4. This will make the grid look better for a briefing or presentation. If you were analyzing something like Bit Error Rates per grid point you might leave this on. By clicking on a point in the 3D Graphics window, you will receive a value for that point. In this scenario, they are on or off.

  4. Click Apply.

Viewing Volumetric 3D Graphics Volume

The Volumetric 3D Graphics Volume page is used to show active grid points or spatial calculation levels. Focus on spatial calculation levels. These levels represent straight line distances from the parent object.

  1. Select the 3D Graphics - Volume page.
  2. Select the Spatial Calculation Levels option.
  3. Click Insert Evenly Spaced Values... at the bottom of the page.
  4. Set the following in the Insert Evenly Spaced Values dialog box:
    5. Option Value
    Units km
    Start Value: 10 (km)
    Stop Value: 700 (km)
    Step Size: 100 (km)
  5. Click Create Values.

Adjusting translucency

You can adjust translucency of the colors in order to make the levels stick out or fade depending on your desired view. In this case, you want to be able to see the lower altitude colors more than the higher altitude colors. The Earth, terrain, and radome affect the lower altitude colors more than the higher altitude colors. You can use the Translucency slider or manually type in the percentage. In this case, type them in.

  1. Set the following in the % column which is located in the Fill Levels list.
    2. Value km %
    10 10
    110 20
    210 40
    310 40
    410 50
    510 50
    610 60
    700 60
  2. Click Apply.

Displaying Volumetric 3D Graphics Legends

The Volumetric 3D Graphics Legends page allows you to place a legend in the 3D Graphics window which explains what the colors mean.

  1. Select the 3D Graphics - Legends page.
  2. Select the Fill Legend tab.
  3. Set the following:
    4. Option Value
    Show Legend on
    Title: Altitude (km)
    Number Of Decimal Digits: 0
    Color Square Width (pixels): 40
  4. Click OK.

Viewing the contours

  1. Bring the 3D Graphics window to the front.
  2. Use your mouse to change your view and get an idea of how obscurations affect the different levels of altitude.

Radar Field of View Obscuration

Summary

A new radar site is being proposed that will track LEO satellites. You loaded analytical terrain into your scenario that covers the area in which the radar site is going to be built. You then used a Sensor object to create the field of view of the radar. You propagated two satellites and generated an access between the sensor and the satellites to create a benchmark access time. Next, you placed a Facility object where a new communications radome will be constructed. You used the AzEl Mask tool to determine if the radome affects the sensor's field of view. Generating another access report, you determined that the radome will affect your overall access time to the satellites. Next, you used the Analysis Workbench Time tool to create a one second interval to be used with a Volumetric object's compute time. Then, using the Analysis Workbench Spatial Analysis tool, you created a reference grid inside of an Area Target object and a constrained grid which then applied the Sensor object's constraints to the 3D volume of space. You determined that a significant amount of your volume is obscured by the Earth, terrain and the radome.

On your own

Throughout the tutorial, hyperlinks were provided that pointed to in depth information of various tools and functions. Now's a good time to go back through this tutorial and view that information. You can add other models to your scenario and determine their obscuration affects. You can adjust the altitude of your reference grid and recalculate volume obscuration. Have fun!