STK OBJECT MODEL TUTORIAL

Follow the instructions in the accompanying tutorial (a PDF file) to enter the following code into your Visual Studio project. The code is organized (1) by sections of the tutorial, then (2) by programming language.

NOTE: Code fragments are tabbed in such a way that the indentation should be correct when you copy them into your project. When copying a line, be sure to select the entire line, starting from the left margin of the page.

* ------------------------------------------------------------- *
* SECTION: Add the Core of the STK Object Model to your Project *
* ------------------------------------------------------------- *

LANGUAGE: C#
------------

1) Add the following using statements to the beginning of Form1.cs:

using AGI.STKObjects;
using AGI.STKUtil;


2) Add this declaration to the beginning of the Form1 class definition:

		private AGI.STKObjects.AgStkObjectRoot root;


3) In the Form1 class constructor, after the InitializeComponent() method, add:

			root = new AGI.STKObjects.AgStkObjectRoot();


4) Subscribe FormClosing Event and close STK Object root properly by adding:

            if (root != null)
            {
                if (root.CurrentScenario != null)
                {
                    root.CloseScenario();
                }

                System.Runtime.InteropServices.Marshal.ReleaseComObject(root);
                root = null;
            }


LANGUAGE: VB.NET
----------------

1) Add the following Imports statements to the beginning of Form1.vb:

Imports AGI.STKObjects
Imports AGI.STKUtil
Imports System.Runtime.InteropServices


2) Add this declaration to the beginning of the Form1 class definition:

    Friend WithEvents root As AGI.STKObjects.AgStkObjectRoot


3) In the Form1 class constructor (if it is already there), after the InitializeComponent() method, add the following line:

        root = New AGI.STKObjects.AgStkObjectRoot
   
     
Your constructor should look like this (please add lines the below if it is not there):
        
        Public Sub New()
		InitializeComponent()
		root = New AGI.STKObjects.AgStkObjectRoot
	End Sub


4) Overload OnFormClosing to close STK Object root properly, add:

	Protected Overrides Sub OnFormClosing(ByVal e As FormClosingEventArgs)
            If (Not Me.root Is Nothing) Then
                If (Not Me.root.CurrentScenario Is Nothing) Then
                    Me.root.CloseScenario
                End If

                Marshal.ReleaseComObject(Me.root)
                Me.root = Nothing
            End If
            MyBase.OnFormClosing(e)
        End Sub


* ------------------------------ *
* SECTION: Create a New Scenario *
* ------------------------------ *

NOTE: SKIP THIS SECTION IF YOU ARE USING THE CUSTOM APPLICATION FRAMEWORK!

LANGUAGE: C#
------------

1) Create a scenario named "OMTutorial"

		public void NewScenario()
		{
			try
			{
				// first close any existing scenario
				root.CloseScenario();
				root.NewScenario("OMTutorial");
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}

2) Add to Click event procedure for New Scenario button:

			NewScenario();


NOTE: SKIP THIS SECTION IF YOU ARE USING THE CUSTOM APPLICATION FRAMEWORK!

LANGUAGE: VB.NET
----------------

1) Create a scenario named "OMTutorial"

    Public Sub NewScenario()
        Try
            ' first close any existing scenario
            root.CloseScenario()
            root.NewScenario("OMTutorial")
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'NewScenario


2) Add to Click event procedure for New Scenario button:

        NewScenario()


* ------------------------------------------- *
* SECTION: Set Time Period & Unit Preferences *
* ------------------------------------------- *

NOTE: SKIP THIS SECTION IF YOU ARE USING THE 4DX APPLICATION FRAMEWORK!

LANGUAGE: C#
------------

In the NewScenario() method, after the call to root.NewScenario(), add:

				// Reset the units to the STK defaults
				IAgUnitPrefsDimCollection dimensions = root.UnitPreferences;
				dimensions.ResetUnits();

				// Set the date unit, acquire an interface to the scenario and use
				// it to set the time period and epoch
				dimensions.SetCurrentUnit("DateFormat", "UTCG");
				IAgScenario scene= (IAgScenario)root.CurrentScenario;			
				scene.StartTime = "1 Jul 2002 00:00:00.00";
				scene.StopTime = "1 Jul 2002 04:00:00.00";
				scene.Epoch = "1 Jul 2002 00:00:00.00";

				// Set new preference for Temperature
				dimensions.SetCurrentUnit("Temperature", "degC");

                		comboBox1.Enabled = true;
                		button2.Enabled = true;
               		 	button3.Enabled = true;
              		  	button4.Enabled = true;
                		button5.Enabled = true;
                		button6.Enabled = true;
                		button7.Enabled = true;


NOTE: SKIP THIS SECTION IF YOU ARE USING THE 4DX APPLICATION FRAMEWORK!

LANGUAGE: VB.NET
----------------

In the NewScenario() method, after the call to root.NewScenario(), add:

            ' Reset the units to the STK defaults
            Dim dimensions As IAgUnitPrefsDimCollection = root.UnitPreferences
            dimensions.ResetUnits()

            ' Set the date unit, acquire an interface to the scenario and use
            ' it to set the time period and epoch
            dimensions.SetCurrentUnit("DateFormat", "UTCG")
            Dim scene As IAgScenario = CType(root.CurrentScenario, IAgScenario)
            scene.StartTime = "1 Jul 2002 00:00:00.00"
            scene.StopTime = "1 Jul 2002 04:00:00.00"
            scene.Epoch = "1 Jul 2002 00:00:00.00"

            ' Set new preference for Temperature
            dimensions.SetCurrentUnit("Temperature", "degC")

            ComboBox1.Enabled = True
            Button2.Enabled = True
            Button3.Enabled = True
            Button4.Enabled = True
            Button5.Enabled = True
            Button6.Enabled = True
            Button7.Enabled = True



* -------------------------- *
* SECTION: Create a Facility *
* -------------------------- *

LANGUAGE: C#
------------

1) The following two methods use various options provided by the Object Model to create some facilities:

		public void CreateFacilities()
        {           
            try
            {
                // The code that creates the Baikonur facility uses
                // a fine-grained interface that lets you set each
                // property individually
                baikonur = (IAgFacility)root.CurrentScenario.Children.New(AgESTKObjectType.
                    eFacility, "Baikonur");
				baikonur.UseTerrain = false;
                IAgGeodetic geodetic = (IAgGeodetic)baikonur.Position.ConvertTo(AgEPositionType.eGeodetic);
                geodetic.Lat = 48.0;
                geodetic.Lon = 55.0;
                geodetic.Alt = 0.0;
                baikonur.Position.Assign(geodetic);
                ((IAgStkObject)baikonur).ShortDescription = "Launch Site";
                ((IAgStkObject)baikonur).LongDescription = "Launch site in Kazakhstan. Also known as Tyuratam.";

                // The Perth and Wallops facilities are created with
                // a coarse-grained interface that lets you specify				
                // position type and lat/lon/alt values in a single 
                // helper method (AssignGeodetic)		
                perth = (IAgFacility)root.CurrentScenario.Children.New(AgESTKObjectType.eFacility, "Perth");
                wallops = (IAgFacility)root.CurrentScenario.Children.New(AgESTKObjectType.eFacility, "Wallops");
                perth.Position.AssignGeodetic(-31, 116, 0);
                ((IAgStkObject)perth).ShortDescription = "Australian Tracking Station";
                wallops.Position.AssignGeodetic(37.8602, -75.5095, -0.0127878);
                ((IAgStkObject)wallops).ShortDescription = "NASA Launch Site/Tracking Station";

                // The Seoul and WhiteSands facilities are 
                // created using the Facility Database
                string filelocation = this.GetSTKDataDir("Facility") + @"\stkFacility.fd";
                // For Windows Vista and later Windows operating 								// systems, the database path should be 
                // c:\ProgramData\AGI\STK 9\Databases\Facility\stkFacility.fd
                string command = "ImportFromDB * Facility \"" + filelocation + "\"Class Facility SiteName Seoul Network \"GeoEye\"";
                root.ExecuteCommand(command);
                command = "ImportFromDB * Facility \"" + filelocation + "\"Class Facility SiteName \"White Sands\" Network \"Other\"";
                root.ExecuteCommand(command);
            
                seoul = (IAgFacility)root.CurrentScenario.Children["Seoul"];
                whitesands = (IAgFacility)root.CurrentScenario.Children["White_Sands"];
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        }

		internal string GetSTKDataDir(string DatabaseType)
        {
            string stkDataDir = null;

            try
            {
                AGI.STKUtil.AgExecCmdResult result = (AGI.STKUtil.AgExecCmdResult)this.root.ExecuteCommand("GetDirectory / Database " + DatabaseType);

                stkDataDir = result[0];
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                Console.WriteLine(e.StackTrace);
            }

            return stkDataDir;
        }


2) Add the following to the variable declarations for the Form1 class (after the declaration of root):

		private IAgFacility baikonur,
			perth,
			wallops,
			seoul,
			whitesands;


3) In the Form1 class constructor, after the line where you initialize the root reference, add:

			comboBox1.Items.Add("Create Facilities");
			comboBox1.Items.Add("Change Facilities Color");
			comboBox1.Items.Add("Create Target");
			comboBox1.Items.Add("Create Ship");
			comboBox1.Items.Add("Create Satellites");
			comboBox1.Items.Add("Modify Shuttle Display");
			comboBox1.Items.Add("Create AreaTarget");
			comboBox1.Items.Add("Access");
			comboBox1.Items.Add("Remove Access");
			comboBox1.Items.Add("Create Sensors");
			comboBox1.Items.Add("Limit Sensor Visibility");
			comboBox1.Items.Add("Enlarge Time Period");
			comboBox1.Items.Add("Custom Display Intervals");
			comboBox1.Items.Add("Access Display Intervals");
			comboBox1.Items.Add("Facility Access");
			comboBox1.Items.Add("SunElevationAngle Constraint");
			comboBox1.Items.Add("Range Constraint");


4) In the SelectedIndexChanged() method for the combo box, add:

			int item = comboBox1.SelectedIndex;
			string action = comboBox1.Items[item].ToString();
			root.BeginUpdate(); //Suspends graphics updates until
					    //EndUpdate() is called
			if(action == "Create Facilities")
			{
				CreateFacilities();
			}
			
			root.EndUpdate();


LANGUAGE: VB.NET
----------------

1) The following two methods use various options provided by the Object Model to create some facilities:

    Public Sub CreateFacilities()
        Try
            ' The code that creates the Baikonur facility uses
            ' a fine-grained interface that lets you set each
            ' property individually
            baikonur = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eFacility, "Baikonur"), IAgFacility)
            Dim geodetic As IAgGeodetic = CType(baikonur.Position.ConvertTo(AgEPositionType.eGeodetic), IAgGeodetic)
            geodetic.Lat = 48.0
            geodetic.Lon = 55.0
            geodetic.Alt = 0.0
            baikonur.Position.Assign(geodetic)
            CType(baikonur, IAgStkObject).ShortDescription = "Launch Site"
            CType(baikonur, IAgStkObject).LongDescription = "Launch site in Kazakhstan. Also known as Tyuratam."

            ' The Perth and Wallops facilities are created with
            ' a coarse-grained interface that lets you specify				
            ' position type and lat/lon/alt values in a single 
            ' helper method (AssignGeodetic)		
            perth = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eFacility, "Perth"), IAgFacility)
            wallops = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eFacility, "Wallops"), IAgFacility)
            perth.Position.AssignGeodetic(-31, 116, 0)
            CType(perth, IAgStkObject).ShortDescription = "Australian Tracking Station"
            wallops.Position.AssignGeodetic(37.8602, -75.5095, -0.0127878)
            CType(wallops, IAgStkObject).ShortDescription = "NASA Launch Site/Tracking Station"
            
            Dim filelocation As String = Me.GetSTKDataDir("Facility") + "STKData\Databases\Facility\stkFacility.fd"
            Dim command As String = "ImportFromDB * Facility """ + filelocation + """Class Facility SiteName Seoul Network ""GeoEye"""
            root.ExecuteCommand(command)
            command = "ImportFromDB * Facility """ + filelocation + """Class Facility SiteName ""White Sands"" Network ""Other"""
            root.ExecuteCommand(command)

            seoul = CType(root.CurrentScenario.Children("Seoul"), IAgFacility)
            whitesands = CType(root.CurrentScenario.Children("White_Sands"), IAgFacility)

        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'CreateFacilities

    Friend Function GetSTKDataDir(DatabaseType As String) As String
        Dim stkDataDir As String = Nothing

        Try
            Dim result As AGI.STKUtil.AgExecCmdResult = Me.root.ExecuteCommand("GetDirectory / Database " + DatabaseType)

            stkDataDir = result(0)
        Catch e As Exception
            Console.WriteLine(e.Message)
            Console.WriteLine(e.StackTrace)
        End Try

        Return stkDataDir
    End Function 'GetSTKDataDir


2) Add the following to the variable declarations for the Form1 class:

    Private baikonur, perth, wallops, seoul, whitesands As IAgFacility


3) In the Form1 class constructor, after the line where you initialize the root reference, add:

        ComboBox1.Items.Add("Create Facilities")
        ComboBox1.Items.Add("Change Facilities Color")
        ComboBox1.Items.Add("Create Target")
        ComboBox1.Items.Add("Create Ship")
        ComboBox1.Items.Add("Create Satellites")
        ComboBox1.Items.Add("Modify Shuttle Display")
        ComboBox1.Items.Add("Create AreaTarget")
        ComboBox1.Items.Add("Access")
        ComboBox1.Items.Add("Remove Access")
        ComboBox1.Items.Add("Create Sensors")
        ComboBox1.Items.Add("Limit Sensor Visibility")
        ComboBox1.Items.Add("Enlarge Time Period")
        ComboBox1.Items.Add("Custom Display Intervals")
        ComboBox1.Items.Add("Access Display Intervals")
        ComboBox1.Items.Add("Facility Access")
        ComboBox1.Items.Add("SunElevationAngle Constraint")
        ComboBox1.Items.Add("Range Constraint")


4) In the SelectedIndexChanged() method for the combo box, add:

        Dim item As Integer = ComboBox1.SelectedIndex
        Dim action As String = ComboBox1.Items(item).ToString()
        root.BeginUpdate() 'Suspends graphics updates until
        'EndUpdate() is called
        Select Case action
            Case "Create Facilities"
                CreateFacilities()
        End Select

        root.EndUpdate()


* ------------------------------------- *
* SECTION: Set Some Facility Properties *
* ------------------------------------- *

LANGUAGE: C#
------------

1) Add a method to change the display colors for the facilities:

		public void ChangeFacilitiesColor()
        {
            try
            {
                baikonur.Graphics.Color = System.Drawing.Color.Yellow;
                perth.Graphics.Color = System.Drawing.Color.Green;
                wallops.Graphics.Color = System.Drawing.Color.Aquamarine;
                seoul.Graphics.Color = System.Drawing.Color.Purple;
                whitesands.Graphics.Color = System.Drawing.Color.Pink;
            }

            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        }



2) Add the following if-else block to the SelectedIndexChanged() method for the combo box:

			else if(action == "Change Facilities Color")
			{
				ChangeFacilitiesColor();
			}


LANGUAGE: VB.NET
----------------

1) Add a method to change the display colors for the facilities:

    Public Sub ChangeFacilitiesColor()
        Try
            baikonur.Graphics.Color = System.Drawing.Color.Yellow
                perth.Graphics.Color = System.Drawing.Color.Green
                wallops.Graphics.Color = System.Drawing.Color.Aquamarine
                seoul.Graphics.Color = System.Drawing.Color.Purple
                whitesands.Graphics.Color = System.Drawing.Color.Pink

        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'ChangeFacilitiesColor


2) Add the following case to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Change Facilities Color"
                ChangeFacilitiesColor()


* ------------------------ *
* SECTION: Create a Target *
* ------------------------ *

LANGUAGE: C#
------------

1) Add a method to create a target:

		public void CreateTarget()
		{
			//Create a Target object named "Iceberg", then use a coarse-grained interface
			//to select Geodetic as the position type and set its lat/lon/alt values, and enter
			//a short description
			try
			{
				IAgTarget iceberg = (IAgTarget)root.CurrentScenario.Children.New(AgESTKObjectType. eTarget, "Iceberg");
				iceberg.Position.AssignGeodetic(74.91, -74.5, 0.0);
				((IAgStkObject)iceberg).ShortDescription = "Only the tip.";
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}


2) Add the following else-if block to the SelectedIndexChanged() method for the combo box:

			else if(action == "Create Target")
			{
				CreateTarget();
			}


LANGUAGE: VB.NET
----------------

1) Add a method to create a target:

    Public Sub CreateTarget()
        'Create a Target object named "Iceberg", then use a coarse-grained interface
        'to select Geodetic as the position type and set its lat/lon/alt values, and enter
        'a short description
        Try
            Dim iceberg As IAgTarget = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eTarget, "Iceberg"), IAgTarget)

            iceberg.Position.AssignGeodetic(74.91, -74.5, 0.0)
            CType(iceberg, IAgStkObject).ShortDescription = "Only the tip."
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'CreateTarget


2) Add the following case to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Create Target"
                CreateTarget()


* ---------------------- *
* SECTION: Create a Ship *
* ---------------------- *

LANGUAGE: C#
------------

1) Add a convenience method for definition of new waypoints, then use it in the method for creating a ship:

    private void AddWaypoint(IAgVeWaypointsCollection waypoints, object lat, object lon, double alt, double speed, double tr)
        {
            IAgVeWaypointsElement elem = waypoints.Add();
            elem.Latitude = (double)lat;
            elem.Longitude = (double)lon;
            elem.Altitude = alt;
            elem.Speed = speed;
            elem.TurnRadius = tr;
        }

		public void CreateShip()
        {
            try
            {
                IAgShip cruise = (IAgShip)root.CurrentScenario.Children.New(AgESTKObjectType.eShip, "Cruise");
                cruise.SetRouteType(AgEVePropagatorType.ePropagatorGreatArc);
                IAgVePropagatorGreatArc greatArc = (IAgVePropagatorGreatArc)cruise.Route;                
                greatArc.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.00", "1 Jul 2002 00:00:00.00");
                greatArc.Method = AgEVeWayPtCompMethod.eDetermineTimeAccFromVel;                


                //Use the convenience method defined above
                //to add waypoints specifying the ship's route
                AddWaypoint(greatArc.Waypoints, 44.1, -8.5, 0.0, .015, 0.0);
                AddWaypoint(greatArc.Waypoints, 51.0, -26.6, 0.0, .015, 0.0);
                AddWaypoint(greatArc.Waypoints, 52.1, -40.1, 0.0, .015, 0.0);
                AddWaypoint(greatArc.Waypoints, 60.2, -55.0, 0.0, .015, 0.0);
                AddWaypoint(greatArc.Waypoints, 68.2, -65.0, 0.0, .015, 0.0);
                AddWaypoint(greatArc.Waypoints, 72.5, -70.1, 0.0, .015, 0.0);
                AddWaypoint(greatArc.Waypoints, 74.9, -74.5, 0.0, .015, 0.0);

                cruise.SetAttitudeType(AgEVeAttitude.eAttitudeStandard);
                IAgVeRouteAttitudeStandard attitude = (IAgVeRouteAttitudeStandard)cruise.Attitude;
                attitude.Basic.SetProfileType(AgEVeProfile.
                    eProfileECFVelocityAlignmentWithRadialConstraint);
                cruise.Graphics.WaypointMarker.IsWaypointMarkersVisible = true;
                cruise.Graphics.WaypointMarker.IsTurnMarkersVisible = true;
                greatArc.Propagate();
                root.Rewind();
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        }


2) Add the following else-if block to the SelectedIndexChanged() method for the combo box:

			else if(action == "Create Ship")
			{
				CreateShip();
			}


LANGUAGE: VB.NET
----------------

1) Add a convenience method for definition of new waypoints, then use it in the method for creating a ship:

    Private Sub AddWaypoint(ByVal waypoints As IAgVeWaypointsCollection, ByVal Lat As Object, ByVal Lon As Object, ByVal Alt As Double, ByVal Speed As Double, ByVal tr As Double)
        Dim elem As IAgVeWaypointsElement = waypoints.Add()
        elem.Latitude = CDbl(Lat)
        elem.Longitude = CDbl(Lon)
        elem.Altitude = Alt
        elem.Speed = Speed
        elem.TurnRadius = tr
    End Sub 'AddWaypoint

    Public Sub CreateShip()
        Try
            Dim cruise As IAgShip = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eShip, "Cruise"), IAgShip)
            cruise.SetRouteType(AgEVePropagatorType.ePropagatorGreatArc)
            Dim greatArc As IAgVePropagatorGreatArc = CType(cruise.Route, IAgVePropagatorGreatArc)            
            greatArc.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.00", "1 Jul 2002 00:00:00.00")
            greatArc.Method = AgEVeWayPtCompMethod.eDetermineTimeAccFromVel

            'Use the convenience method defined above
            'to add waypoints specifying the ship's route
            AddWaypoint(greatArc.Waypoints, 44.1, -8.5, 0.0, 0.015, 0.0)
            AddWaypoint(greatArc.Waypoints, 51.0, -26.6, 0.0, 0.015, 0.0)
            AddWaypoint(greatArc.Waypoints, 52.1, -40.1, 0.0, 0.015, 0.0)
            AddWaypoint(greatArc.Waypoints, 60.2, -55.0, 0.0, 0.015, 0.0)
            AddWaypoint(greatArc.Waypoints, 68.2, -65.0, 0.0, 0.015, 0.0)
            AddWaypoint(greatArc.Waypoints, 72.5, -70.1, 0.0, 0.015, 0.0)
            AddWaypoint(greatArc.Waypoints, 74.9, -74.5, 0.0, 0.015, 0.0)

            cruise.SetAttitudeType(AgEVeAttitude.eAttitudeStandard)
            Dim attitude As IAgVeRouteAttitudeStandard = CType(cruise.Attitude, IAgVeRouteAttitudeStandard)
            attitude.Basic.SetProfileType(AgEVeProfile.eProfileECFVelocityAlignmentWithRadialConstraint)
            cruise.Graphics.WaypointMarker.IsWaypointMarkersVisible = True
            cruise.Graphics.WaypointMarker.IsTurnMarkersVisible = True
            greatArc.Propagate()
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'CreateShip


2) Add the following case to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Create Ship"
                CreateShip()


* ------------------------------- *
* SECTION: Create Some Satellites *
* ------------------------------- *

LANGUAGE: C#
------------

1) Add a method to create some satellites:

		public void CreateSatellites()
        {
            try
            {
                //SATELLITE #1: TDRS
                //Assign a two-body propagator to propagate it
                IAgSatellite tdrs = (IAgSatellite)root.CurrentScenario.Children.New(AgESTKObjectType.
                    eSatellite, "TDRS");
                tdrs.SetPropagatorType(AgEVePropagatorType.ePropagatorTwoBody);
                IAgVePropagatorTwoBody twobody = (IAgVePropagatorTwoBody)tdrs.Propagator;

                //Define the TDRS satellite's orbit using
                //classical (Keplerian) orbital elements
                IAgOrbitStateClassical classical = (IAgOrbitStateClassical)twobody.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical);

                //Set J2000 as the coordinate system
                //and set the time period and time step
                classical.CoordinateSystemType = AgECoordinateSystem.eCoordinateSystemJ2000;
                twobody.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000", "1 Jul 2002 04:00:00.000");               
                twobody.Step = 60;

                //Use period and eccentricity to define the size
                //and shape of the orbit
                classical.SizeShapeType = AgEClassicalSizeShape.eSizeShapePeriod;
                IAgClassicalSizeShapePeriod period = (IAgClassicalSizeShapePeriod)classical.SizeShape;
                period.Eccentricity = 0.0;
                period.Period = 86164.090540;

                //Use argument of perigee, inclination
                //and longitude of ascending node to
                //define the orientation of the orbit
                classical.Orientation.ArgOfPerigee = 0.0;
                classical.Orientation.Inclination = 0.0;
                classical.Orientation.AscNodeType = AgEOrientationAscNode.eAscNodeLAN;
                IAgOrientationAscNodeLAN lan = (IAgOrientationAscNodeLAN)classical.Orientation.AscNode;
                lan.Value = 259.999982;

                //Use true anomaly to specify the position of
                //the satellite in orbit
                classical.LocationType = AgEClassicalLocation.eLocationTrueAnomaly;
                IAgClassicalLocationTrueAnomaly trueAnomaly = (IAgClassicalLocationTrueAnomaly)classical.Location;
                trueAnomaly.Value = 178.845262;

                //Assign the orbital elements to the TDRS
                //satellite's propagator and propagate the orbit	
                twobody.InitialState.Representation.Assign(classical);
                twobody.Propagate();

                //SATELLITE #2: TDRS 3
                //Use the ImportFromDB Connect command
                //to import a satellite from the STK Satellite
                //Database
                string filelocation = this.GetSTKDataDir("Satellite") + @"\stkSatDB.sd";
                string command = "ImportFromDB * Satellite \"" + filelocation + "\" Propagate On CommonName \"TDRS 3\"";
                root.ExecuteCommand(command);

                IAgSatellite tdrs3 = (IAgSatellite)root.CurrentScenario.Children["TDRS_3_19548"];

                //Assign an SGP4 propagator to the TDRS 3
                //satellite and set its time period
                IAgVePropagatorSGP4 sgp4 = (IAgVePropagatorSGP4)tdrs3.Propagator;

                sgp4.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000","1 Jul 2002 04:00:00.000");
            
                //SATELLITE #3: ERS1
                //Assign a J4 Perturbation propagator to the
                //satellite and set various time properties		
                ers1 = (IAgSatellite)root.CurrentScenario.Children.New(AgESTKObjectType.
                    eSatellite, "ERS1");
                ers1.SetPropagatorType(AgEVePropagatorType.
                    ePropagatorJ4Perturbation);
                IAgVePropagatorJ4Perturbation j4 = (IAgVePropagatorJ4Perturbation)ers1.Propagator;
                j4.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000","1 Jul 2002 04:00:00.000");              
                j4.Step = 60.00;               
                j4.InitialState.OrbitEpoch.SetExplicitTime("1 Jul 2002 00:00:00.00");

                //Use Keplerian elements to define the orbit
                //as you did for the TDRS satellite, but use
                //semimajor axis and eccentricity to define the
                //size and shape of the orbit
                classical = (IAgOrbitStateClassical)j4.InitialState.Representation.
                    ConvertTo(AgEOrbitStateType.eOrbitStateClassical);
                classical.CoordinateSystemType = AgECoordinateSystem.eCoordinateSystemJ2000;
                classical.LocationType = AgEClassicalLocation.eLocationTrueAnomaly;
                trueAnomaly = (IAgClassicalLocationTrueAnomaly)classical.Location;
                trueAnomaly.Value = 0.0;
                classical.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis;
                IAgClassicalSizeShapeSemimajorAxis semi = (IAgClassicalSizeShapeSemimajorAxis)classical.SizeShape;
                semi.SemiMajorAxis = 7163.14;
                semi.Eccentricity = 0.0;
                classical.Orientation.ArgOfPerigee = 0.0;
                classical.Orientation.AscNodeType = AgEOrientationAscNode.eAscNodeLAN;
                lan = (IAgOrientationAscNodeLAN)classical.Orientation.AscNode;
                lan.Value = 99.38;
                classical.Orientation.Inclination = 98.50;

                j4.InitialState.Representation.Assign(classical);
                j4.Propagate();

                root.Rewind();

                //If you uncomment the following line, only
                //the descending (north-to-south) portion of 
                //each orbit pass of ERS1 is displayed.
                //NOTE: Be sure to re-comment (or remove) the line,
                //since full path display is needed for some
                //later activities

                //ers1.Graphics.Passes.VisibleSides = AgEVeGfxVisibleSides.eVisibleSidesDescending;

                //SATELLITE #4: Shuttle
                //Here you use the J4 Perturbation propagator again,
                //as well as Keplerian elements, with orbit size and
                //shape specified via apogee and perigee altitude
                shuttle = (IAgSatellite)root.CurrentScenario.Children.New(AgESTKObjectType.
                    eSatellite, "Shuttle");
                shuttle.SetPropagatorType(AgEVePropagatorType.
                    ePropagatorJ4Perturbation);
                j4 = (IAgVePropagatorJ4Perturbation)shuttle.Propagator;
                j4.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000", "1 Jul 2002 03:00:00.000");               
                j4.Step = 60.00;

                j4.InitialState.OrbitEpoch.SetExplicitTime("1 Jul 2002 00:00:00.00");
                classical = (IAgOrbitStateClassical)j4.InitialState.Representation.
                    ConvertTo(AgEOrbitStateType.eOrbitStateClassical);
                classical.CoordinateSystemType = AgECoordinateSystem.eCoordinateSystemJ2000;
                classical.LocationType = AgEClassicalLocation.eLocationTrueAnomaly;
                trueAnomaly = (IAgClassicalLocationTrueAnomaly)classical.Location;
                trueAnomaly.Value = 0.0;
                classical.SizeShapeType = AgEClassicalSizeShape.eSizeShapeAltitude;
                IAgClassicalSizeShapeAltitude altitude = (IAgClassicalSizeShapeAltitude)classical.SizeShape;
                altitude.ApogeeAltitude = 370.4;
                altitude.PerigeeAltitude = 370.4;
                classical.Orientation.ArgOfPerigee = 0.0;
                classical.Orientation.AscNodeType = AgEOrientationAscNode.eAscNodeLAN;
                lan = (IAgOrientationAscNodeLAN)classical.Orientation.AscNode;
                lan.Value = -151.0;
                classical.Orientation.Inclination = 28.5;
                j4.InitialState.Representation.Assign(classical);

                j4.Propagate();
                root.Rewind();
            }
            catch (Exception e)
            {
                MessageBox.Show(e.Message);
            }
        }


2) Add the following to the variable declarations for the Form1 class:

		private IAgSatellite ers1, shuttle;


3) Add the following else-if block to the SelectedIndexChanged() method for the combo box:

			else if(action == "Create Satellites")
			{
				CreateSatellites();
			}


4) Add a method to modify the display of the Shuttle's orbit, change the marker and add contours:

		public void ModifyShuttleDisplay()
		{
			//Change the display of the Shuttle's orbit and ground
			//tracks to a dashed line, change the marker style to a 
			//plus, and add elevation contours
			try
			{
				shuttle.Graphics.SetAttributesType(AgEVeGfxAttributes.
					eAttributesBasic);
				IAgVeGfxAttributesOrbit orbitgfx = (IAgVeGfxAttributesOrbit)shuttle.Graphics.Attributes;
				orbitgfx.Line.Style = AgELineStyle.eDashed;
				orbitgfx.MarkerStyle = "Plus";

				IAgVeGfxElevContours contours = (IAgVeGfxElevContours)shuttle.Graphics.ElevContours;
				IAgVeGfxElevationsCollection elevations = contours.Elevations;
				elevations.RemoveAll();

				//Define contour levels for ground elevation
				//angles from 0 to 50 deg in steps of 10 deg
				elevations.AddLevelRange(0, 50, 10);

				for(int i = 0; i < elevations.Count; i++)

					//Draw each of the 6 contour lines with no label
					//and with a medium-thick line width
				{
					IAgVeGfxElevationsElement elem = elevations[i];
					elem.DistanceVisible = false;
					elem.LineWidth = AgELineWidth.e3;
				}

				//Show the contours!
				contours.IsVisible = true;

				root.Rewind();
			}
			catch (Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}



5) Add the following else-if block to the SelectedIndexChanged() method for the combo box:

			else if(action == "Modify Shuttle Display")
			{
				ModifyShuttleDisplay();
			}


LANGUAGE: VB.NET
----------------

1) Add a method to create some satellites:

    Public Sub CreateSatellites()
        Try
            'SATELLITE #1: TDRS
            'Assign a two-body propagator to propagate it
            Dim tdrs As IAgSatellite = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eSatellite, "TDRS"), IAgSatellite)
            tdrs.SetPropagatorType(AgEVePropagatorType.ePropagatorTwoBody)
            Dim twobody As IAgVePropagatorTwoBody = CType(tdrs.Propagator, IAgVePropagatorTwoBody)

            'Define the TDRS satellite's orbit using
            'classical (Keplerian) orbital elements
            Dim classical As IAgOrbitStateClassical = CType(twobody.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical), IAgOrbitStateClassical)

            'Set J2000 as the coordinate system
            'and set the time period and time step
            classical.CoordinateSystemType = AgECoordinateSystem.eCoordinateSystemJ2000
            twobody.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000", "1 Jul 2002 04:00:00.000")              
            twobody.Step = 60

            'Use period and eccentricity to define the size
            'and shape of the orbit
            classical.SizeShapeType = AgEClassicalSizeShape.eSizeShapePeriod
            Dim period As IAgClassicalSizeShapePeriod = CType(classical.SizeShape, IAgClassicalSizeShapePeriod)
            period.Eccentricity = 0.0
            period.Period = 86164.09054

            'Use argument of perigee, inclination
            'and longitude of ascending node to
            'define the orientation of the orbit
            classical.Orientation.ArgOfPerigee = 0.0
            classical.Orientation.Inclination = 0.0
            classical.Orientation.AscNodeType = AgEOrientationAscNode.eAscNodeLAN
            Dim lan As IAgOrientationAscNodeLAN = CType(classical.Orientation.AscNode, IAgOrientationAscNodeLAN)
            lan.Value = 259.999982

            'Use true anomaly to specify the position of
            'the satellite in orbit
            classical.LocationType = AgEClassicalLocation.eLocationTrueAnomaly
            Dim trueAnomaly As IAgClassicalLocationTrueAnomaly = CType(classical.Location, IAgClassicalLocationTrueAnomaly)
            trueAnomaly.Value = 178.845262

            'Assign the orbital elements to the TDRS
            'satellite's propagator and propagate the orbit	
            twobody.InitialState.Representation.Assign(classical)
            twobody.Propagate()

            'SATELLITE #2: TDRS 3
            'Use the ImportFromDB Connect command
            'to import a satellite from the STK Satellite
            'Database
            Dim filelocation As String = Me.GetSTKDataDir("Satellite") + "\stkSatDB.sd"
            Dim command As String = "ImportFromDB * Satellite """ + filelocation + """ Propagate On CommonName ""TDRS 3"""
            root.ExecuteCommand(command)

            Dim tdrs3 As IAgSatellite = CType(root.CurrentScenario.Children("TDRS_3_19548"), IAgSatellite)

            'Assign an SGP4 propagator to the TDRS 3
            'satellite and set its time period
            Dim sgp4 As IAgVePropagatorSGP4 = CType(tdrs3.Propagator, IAgVePropagatorSGP4)

            sgp4.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000","1 Jul 2002 04:00:00.000")

            'SATELLITE #3: ERS1
            'Assign a J4 Perturbation propagator to the
            'satellite and set various time properties		
            ers1 = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eSatellite, "ERS1"), IAgSatellite)
            ers1.SetPropagatorType(AgEVePropagatorType.ePropagatorJ4Perturbation)
            Dim j4 As IAgVePropagatorJ4Perturbation = CType(ers1.Propagator, IAgVePropagatorJ4Perturbation)
            j4.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000","1 Jul 2002 04:00:00.000")              
            j4.Step = 60.0
            j4.InitialState.OrbitEpoch.SetExplicitTime("1 Jul 2002 00:00:00.00")

            'Use Keplerian elements to define the orbit
            'as you did for the TDRS satellite, but use
            'semimajor axis and eccentricity to define the
            'size and shape of the orbit
            classical = CType(j4.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical), IAgOrbitStateClassical)
            classical.CoordinateSystemType = AgECoordinateSystem.eCoordinateSystemJ2000
            classical.LocationType = AgEClassicalLocation.eLocationTrueAnomaly
            trueAnomaly = CType(classical.Location, IAgClassicalLocationTrueAnomaly)
            trueAnomaly.Value = 0.0
            classical.SizeShapeType = AgEClassicalSizeShape.eSizeShapeSemimajorAxis
            Dim semi As IAgClassicalSizeShapeSemimajorAxis = CType(classical.SizeShape, IAgClassicalSizeShapeSemimajorAxis)
            semi.SemiMajorAxis = 7163.14
            semi.Eccentricity = 0.0
            classical.Orientation.ArgOfPerigee = 0.0
            classical.Orientation.AscNodeType = AgEOrientationAscNode.eAscNodeLAN
            lan = CType(classical.Orientation.AscNode, IAgOrientationAscNodeLAN)
            lan.Value = 99.38
            classical.Orientation.Inclination = 98.5

            j4.InitialState.Representation.Assign(classical)
            j4.Propagate()

            root.Rewind()

            'If you uncomment the following line, only
            'the descending (north-to-south) portion of 
            'each orbit pass of ERS1 is displayed.
            'NOTE: Be sure to re-comment (or remove) the line,
            'since full path display is needed for some
            'later activities
            'ers1.Graphics.Passes.VisibleSides = AgEVeGfxVisibleSides.eVisibleSidesDescending;
            
            'SATELLITE #4: Shuttle
            'Here you use the J4 Perturbation propagator again,
            'as well as Keplerian elements, with orbit size and
            'shape specified via apogee and perigee altitude
            shuttle = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eSatellite, "Shuttle"), IAgSatellite)
            shuttle.SetPropagatorType(AgEVePropagatorType.ePropagatorJ4Perturbation)
            j4 = CType(shuttle.Propagator, IAgVePropagatorJ4Perturbation)
            j4.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000", "1 Jul 2002 03:00:00.000")              
            j4.Step = 60.0

            j4.InitialState.OrbitEpoch.SetExplicitTime("1 Jul 2002 00:00:00.00")
            classical = CType(j4.InitialState.Representation.ConvertTo(AgEOrbitStateType.eOrbitStateClassical), IAgOrbitStateClassical)
            classical.CoordinateSystemType = AgECoordinateSystem.eCoordinateSystemJ2000
            classical.LocationType = AgEClassicalLocation.eLocationTrueAnomaly
            trueAnomaly = CType(classical.Location, IAgClassicalLocationTrueAnomaly)
            trueAnomaly.Value = 0.0
            classical.SizeShapeType = AgEClassicalSizeShape.eSizeShapeAltitude
            Dim altitude As IAgClassicalSizeShapeAltitude = CType(classical.SizeShape, IAgClassicalSizeShapeAltitude)
            altitude.ApogeeAltitude = 370.4
            altitude.PerigeeAltitude = 370.4
            classical.Orientation.ArgOfPerigee = 0.0
            classical.Orientation.AscNodeType = AgEOrientationAscNode.eAscNodeLAN
            lan = CType(classical.Orientation.AscNode, IAgOrientationAscNodeLAN)
            lan.Value = -151.0
            classical.Orientation.Inclination = 28.5
            j4.InitialState.Representation.Assign(classical)

            j4.Propagate()
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'CreateSatellites


2) Add the following to the variable declarations for the Form1 class:

    Private ers1, shuttle As IAgSatellite


3) Add the following case to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Create Satellites"
                CreateSatellites()


4) Add a method to modify the display of the Shuttle's orbit, change the marker and add contours:

    Public Sub ModifyShuttleDisplay()
        'Change the display of the Shuttle's orbit and ground
        'tracks to a dashed line, change the marker style to a 
        'plus, and add elevation contours
        Try
            shuttle.Graphics.SetAttributesType(AgEVeGfxAttributes.eAttributesBasic)
            Dim orbitgfx As IAgVeGfxAttributesOrbit = CType(shuttle.Graphics.Attributes, IAgVeGfxAttributesOrbit)
            orbitgfx.Line.Style = AgELineStyle.eDashed
            orbitgfx.MarkerStyle = "Plus"

            Dim contours As IAgVeGfxElevContours = CType(shuttle.Graphics.ElevContours, IAgVeGfxElevContours)
            Dim elevations As IAgVeGfxElevationsCollection = contours.Elevations
            elevations.RemoveAll()

            'Define contour levels for ground elevation
            'angles from 0 to 50 deg in steps of 10 deg
            elevations.AddLevelRange(0, 50, 10)

            Dim i As Integer
            For i = 0 To elevations.Count - 1

                'Draw each of the 6 contour lines with no label
                'and with a medium-thick line width
                Dim elem As IAgVeGfxElevationsElement = elevations(i)
                elem.DistanceVisible = False
                elem.LineWidth = AgELineWidth.e3
            Next i

            'Show the contours!
            contours.IsVisible = True

            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'ModifyShuttleDisplay


5) Add the following case to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Modify Shuttle Display"
                ModifyShuttleDisplay()


* ----------------------- *
* SECTION: Compute Access *
* ----------------------- *

LANGUAGE: C#
------------

1) Add a method to create an area target and one to compute access:

		public void CreateAreaTarget()
		{
			//Create an area target near the North Pole
			try
			{
				searchArea = (IAgAreaTarget)root.CurrentScenario.Children.New(AgESTKObjectType. eAreaTarget, "SearchArea");

				//Set some graphics properties for the area target
				IAgATGraphics atGfx = searchArea.Graphics;
				atGfx.MarkerStyle = "None";
				atGfx.Inherit = false;
				atGfx.LabelVisible = false;
				atGfx.CentroidVisible = false;

				//Select the Pattern type for defining the 
				//area target boundary, and add lat/lon values
				searchArea.AreaType = AgEAreaType.ePattern;
				IAgAreaTypePatternCollection patterns = (IAgAreaTypePatternCollection)searchArea.AreaTypeData;
				patterns.Add(78.4399, -77.6125);
				patterns.Add(77.7879, -71.1578);
				patterns.Add(74.5279, -69.0714);
				patterns.Add(71.6591, -69.1316);
				patterns.Add(70.0291, -70.8318);
				patterns.Add(71.9851, -76.3086);

				searchArea.AutoCentroid = false;
				//A course-grained method is convenient for defining
				//the position of the area target centroid. The 
				//AssignSpherical method lets you set select the 
				//Spherical position type and set latitude,
				//longitude and radius in one step
				searchArea.Position.AssignSpherical(74.9533, 
					-74.5482, 6358.186790);		
			}
			catch (Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}

		public void ComputeAccess()
		{
			//Compute access from the ERS1 satellite to the area target
			try
			{
				//Specify the 'from' and 'to' objects
				access = ((IAgStkObject)ers1).GetAccessToObject((IAgStkObject)searchArea);
				access.ComputeAccess();
				root.Rewind();

				IAgDataPrvInterval interval = (IAgDataPrvInterval)access.DataProviders["Access Data"];

				IAgDrResult result = (IAgDrResult)interval.Exec("1 Jul 2002 00:00:00.000", "1 Jul 2002 04:00:00.000");
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		
			//with the result returned, the user can use the data any way they prefer.
		}


2) Add the following to the variable declarations for the Form1 class:

		private IAgAreaTarget searchArea;
		private IAgStkAccess access;


3) Add the following else-if blocks to the SelectedIndexChanged() method for the combo box:

			else if(action == "Create AreaTarget")
			{
				CreateAreaTarget();
			}
			else if(action == "Access")
			{
				ComputeAccess();
			}

4) Add a method to remove access:


		public void RemoveAccess()
		{
			try
			{
				access.RemoveAccess();
				root.Rewind();
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}


5) Add the following else-if block to the SelectedIndexChanged() method for the combo box:

			else if(action == "Remove Access")
			{
				RemoveAccess();
			}


LANGUAGE: VB.NET
----------------

1) Add a method to create an area target and one to compute access:

    Public Sub CreateAreaTarget()
        'Create an area target near the North Pole
        Try
            searchArea = CType(root.CurrentScenario.Children.New(AgESTKObjectType.eAreaTarget, "SearchArea"), IAgAreaTarget)

            'Set some graphics properties for the area target
            Dim atGfx As IAgATGraphics = searchArea.Graphics
            atGfx.MarkerStyle = "None"
            atGfx.Inherit = False
            atGfx.LabelVisible = False
            atGfx.CentroidVisible = False

            'Select the Pattern type for defining the 
            'area target boundary, and add lat/lon values
            searchArea.AreaType = AgEAreaType.ePattern
            Dim patterns As IAgAreaTypePatternCollection = CType(searchArea.AreaTypeData, IAgAreaTypePatternCollection)
            patterns.Add(78.4399, -77.6125)
            patterns.Add(77.7879, -71.1578)
            patterns.Add(74.5279, -69.0714)
            patterns.Add(71.6591, -69.1316)
            patterns.Add(70.0291, -70.8318)
            patterns.Add(71.9851, -76.3086)

            searchArea.AutoCentroid = False
            'A course-grained method is convenient for defining
            'the position of the area target centroid. The 
            'AssignSpherical method lets you set select the 
            'Spherical position type and set latitude,
            'longitude and radius in one step
            searchArea.Position.AssignSpherical(74.9533, -74.5482, 6358.18679)
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'CreateAreaTarget

    Public Sub ComputeAccess()
        'Compute access from the ERS1 satellite to the area target
        Try
            'Specify the 'from' and 'to' objects
            access = CType(ers1, IAgStkObject).GetAccessToObject(CType(searchArea, IAgStkObject))
            access.ComputeAccess()
            root.Rewind()

            Dim interval As IAgDataPrvInterval = CType(access.DataProviders("Access Data"), IAgDataPrvInterval)

            Dim result As IAgDrResult = CType(interval.Exec("1 Jul 2002 00:00:00.000", "1 Jul 2002 04:00:00.000"), IAgDrResult)
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'Access 
    'with the result returned, the user can use the data any way they prefer.


2) Add the following to the variable declarations for the Form1 class:

    Private searchArea As IAgAreaTarget
    Private access As IAgStkAccess


3) Add the following else-if blocks to the SelectedIndexChanged() method for the combo box:

            Case "Create AreaTarget"
                CreateAreaTarget()
            Case "Access"
                ComputeAccess()

4) Add a method to remove access:


    Public Sub RemoveAccess()
        Try
            access.RemoveAccess()
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'RemoveAccess



5) Add the following case to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Remove Access"
                RemoveAccess()


* ---------------------------- *
* SECTION: Create Some Sensors *
* ---------------------------- *

LANGUAGE: C#
------------

1) Add a method to create 2 sensors:

		public void CreateSensors()
		{
			//Attach 2 sensors to the ERS1 satellite
			try
			{
				//SENSOR #1: Horizon
				//Define a simple conic sensor pattern with
				//a cone angle of 90 deg
				horizon = (IAgSensor)root.CurrentScenario.Children["ERS1"].Children.
					New(AgESTKObjectType.eSensor, "Horizon");
				horizon.SetPatternType(AgESnPattern.eSnSimpleConic);
				IAgSnSimpleConicPattern simpleConic  = (IAgSnSimpleConicPattern)horizon.Pattern;
				simpleConic.ConeAngle = 90;
			
				//Select a Fixed pointing type and the Az-El
				//orientation type, and set the elevation angle to
				//90 deg, so that the sensor points straight down
				//with reference to the satellite
				horizon.SetPointingType(AgESnPointing.eSnPtFixed);
				IAgSnPtFixed fixedPt = (IAgSnPtFixed)horizon.Pointing;
				IAgOrientationAzEl azEl = (IAgOrientationAzEl)fixedPt.Orientation.ConvertTo(AgEOrientationType.
					eAzEl);
				azEl.Elevation = 90;
				azEl.AboutBoresight = AgEAzElAboutBoresight.eAzElAboutBoresightRotate;
				fixedPt.Orientation.Assign(azEl);

				//Some cleanup: remove the ERS1 elevation contours
				//from the 2D window
				ers1.Graphics.ElevContours.IsVisible = false;

				//SENSOR #2: Downlink
				//Define a half power sensor with the parameters
				//specified below
				IAgSensor downlink = (IAgSensor)root.CurrentScenario.Children["ERS1"].Children.
					New(AgESTKObjectType.eSensor, "Downlink");
				downlink.SetPatternType(AgESnPattern.eSnHalfPower);
				IAgSnHalfPowerPattern halfpower = (IAgSnHalfPowerPattern)downlink.Pattern;
				halfpower.Frequency = .85;
				halfpower.AntennaDiameter = 1.0;

				//Select the Targeted pointing type with a tracking
				//boresight, and target the sensor to point at the
				//facilities that you created
				downlink.SetPointingType(AgESnPointing.eSnPtTargeted);
				IAgSnPtTargeted targeted = (IAgSnPtTargeted)downlink.Pointing;
				targeted.Boresight = AgESnPtTrgtBsightType.eSnPtTrgtBsightTracking;
				IAgSnTargetCollection targets = targeted.Targets;
				targets.Add("Facility/Baikonur");
				targets.Add("Facility/White_Sands");
				targets.Add("Facility/Perth");
				targets.AddObject((IAgStkObject)seoul);
				targets.Add(((IAgStkObject)wallops).Path);

				root.Rewind();

			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}


2) Add the following to the variable declarations for the Form1 class:

		private IAgSensor horizon;


3) Add the following else-if block to the SelectedIndexChanged() method for the combo box:

			else if(action == "Create Sensors")
			{
				CreateSensors();
			}


4) Add a new sensor defined to have a 5 degree elevation requirement on visibility:

		public void LimitSensorVisibility()	
		{
			try
			{
				//Attach a sensor named "FiveDegElev" to the Wallops 
				//facility
				IAgSensor fiveDegElev = (IAgSensor)root.CurrentScenario.Children["Wallops"].Children.
					New(AgESTKObjectType.eSensor, "FiveDegElev");

				//Define a Complex Conic sensor pattern with an outer
				//cone half-angle of 85 to impose a 5 deg elevation
				//requirement on the sensor's visibility
				fiveDegElev.SetPatternType(AgESnPattern.eSnComplexConic);
				IAgSnComplexConicPattern complexConic = (IAgSnComplexConicPattern)fiveDegElev.Pattern;
				complexConic.InnerConeHalfAngle = 0;
				complexConic.OuterConeHalfAngle = 85;
				complexConic.MinimumClockAngle = 0;
				complexConic.MaximumClockAngle = 360;

				//Point the sensor up with respect to the facility
				fiveDegElev.SetPointingType(AgESnPointing.eSnPtFixed);
				IAgSnPtFixed fixedPt = (IAgSnPtFixed)fiveDegElev.Pointing;
				IAgOrientationAzEl azEl = (IAgOrientationAzEl)fixedPt.Orientation.ConvertTo(AgEOrientationType.
					eAzEl);
				//Good example of use of fine-grained interface;
				//you are only setting elevation, not azimuth
				azEl.Elevation= 90;
				azEl.AboutBoresight = AgEAzElAboutBoresight.eAzElAboutBoresightRotate;
				fixedPt.Orientation.Assign(azEl);

				//Set the sensor's 2D Graphics projection properties
				//so that it projects to a specified maximum altitude
				fiveDegElev.Graphics.Projection.DistanceType = AgESnProjectionDistanceType.eConstantAlt;
				IAgSnProjDisplayDistance dispDistance = (IAgSnProjDisplayDistance)fiveDegElev.Graphics.Projection.DistanceData;
				dispDistance.Max = 785.248;
				dispDistance.Min = 0;
				dispDistance.NumberOfSteps = 1;
				root.Rewind();
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}


5) Add the following else-if block to the SelectedIndexChanged() method for the combo box:

			else if(action == "Limit Sensor Visibility")
			{
				LimitSensorVisibility();
			}


LANGUAGE: VB.NET
----------------

1) Add a method to create 2 sensors:

    Public Sub CreateSensors()
        'Attach 2 sensors to the ERS1 satellite
        Try
            'SENSOR #1: Horizon
            'Define a simple conic sensor pattern with
            'a cone angle of 90 deg
            horizon = CType(root.CurrentScenario.Children("ERS1").Children.New(AgESTKObjectType.eSensor, "Horizon"), IAgSensor)
            horizon.SetPatternType(AgESnPattern.eSnSimpleConic)
            Dim simpleConic As IAgSnSimpleConicPattern = CType(horizon.Pattern, IAgSnSimpleConicPattern)
            simpleConic.ConeAngle = 90

            'Select a Fixed pointing type and the Az-El
            'orientation type, and set the elevation angle to
            '90 deg, so that the sensor points straight down
            'with reference to the satellite
            horizon.SetPointingType(AgESnPointing.eSnPtFixed)
            Dim fixedPt As IAgSnPtFixed = CType(horizon.Pointing, IAgSnPtFixed)
            Dim azEl As IAgOrientationAzEl = CType(fixedPt.Orientation.ConvertTo(AgEOrientationType.eAzEl), IAgOrientationAzEl)
            azEl.Elevation = 90
            azEl.AboutBoresight = AgEAzElAboutBoresight.eAzElAboutBoresightRotate
            fixedPt.Orientation.Assign(azEl)

            'Some cleanup: remove the ERS1 elevation contours
            'from the 2D window
            ers1.Graphics.ElevContours.IsVisible = False

            'SENSOR #2: Downlink
            'Define a half power sensor with the parameters
            'specified below
            Dim downlink As IAgSensor = CType(root.CurrentScenario.Children("ERS1").Children.New(AgESTKObjectType.eSensor, "Downlink"), IAgSensor)
            downlink.SetPatternType(AgESnPattern.eSnHalfPower)
            Dim halfpower As IAgSnHalfPowerPattern = CType(downlink.Pattern, IAgSnHalfPowerPattern)
            halfpower.Frequency = 0.85
            halfpower.AntennaDiameter = 1.0

            'Select the Targeted pointing type with a tracking
            'boresight, and target the sensor to point at the
            'facilities that you created
            downlink.SetPointingType(AgESnPointing.eSnPtTargeted)
            Dim targeted As IAgSnPtTargeted = CType(downlink.Pointing, IAgSnPtTargeted)
            targeted.Boresight = AgESnPtTrgtBsightType.eSnPtTrgtBsightTracking
            Dim targets As IAgSnTargetCollection = targeted.Targets
            targets.Add("Facility/Baikonur")
            targets.Add("Facility/White_Sands")
            targets.Add("Facility/Perth")
            targets.AddObject(CType(seoul, IAgStkObject))
            targets.Add(CType(wallops, IAgStkObject).Path)

            root.Rewind()

        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'CreateSensors


2) Add the following to the variable declarations for the Form1 class:

    Private horizon As IAgSensor

3) Add the following case to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Create Sensors"
                CreateSensors()


4) Add a new sensor defined to have a 5 degree elevation requirement on visibility:

    Public Sub LimitSensorVisibility()
        Try
            'Attach a sensor named "FiveDegElev" to the Wallops 
            'facility
            Dim fiveDegElev As IAgSensor = CType(root.CurrentScenario.Children("Wallops").Children.New(AgESTKObjectType.eSensor, "FiveDegElev"), IAgSensor)

            'Define a Complex Conic sensor pattern with an outer
            'cone half-angle of 85 to impose a 5 deg elevation
            'requirement on the sensor's visibility
            fiveDegElev.SetPatternType(AgESnPattern.eSnComplexConic)
            Dim complexConic As IAgSnComplexConicPattern = CType(fiveDegElev.Pattern, IAgSnComplexConicPattern)
            complexConic.InnerConeHalfAngle = 0
            complexConic.OuterConeHalfAngle = 85
            complexConic.MinimumClockAngle = 0
            complexConic.MaximumClockAngle = 360

            'Point the sensor up with respect to the facility
            fiveDegElev.SetPointingType(AgESnPointing.eSnPtFixed)
            Dim fixedPt As IAgSnPtFixed = CType(fiveDegElev.Pointing, IAgSnPtFixed)
            Dim azEl As IAgOrientationAzEl = CType(fixedPt.Orientation.ConvertTo(AgEOrientationType.eAzEl), IAgOrientationAzEl)
            'Good example of use of fine-grained interface;
            'you are only setting elevation, not azimuth
            azEl.Elevation = 90
            azEl.AboutBoresight = AgEAzElAboutBoresight.eAzElAboutBoresightRotate
            fixedPt.Orientation.Assign(azEl)

            'Set the sensor's 2D Graphics projection properties
            'so that it projects to a specified maximum altitude
            fiveDegElev.Graphics.Projection.DistanceType = AgESnProjectionDistanceType.eConstantAlt
            Dim dispDistance As IAgSnProjDisplayDistance = CType(fiveDegElev.Graphics.Projection.DistanceData, IAgSnProjDisplayDistance)
            dispDistance.Max = 785.248
            dispDistance.Min = 0
            dispDistance.NumberOfSteps = 1
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'LimitSensorVisibility


5) Add the following case to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Limit Sensor Visibility"
                LimitSensorVisibility()


* ---------------------------------- *
* SECTION: Control Display Intervals *
* ---------------------------------- *

LANGUAGE: C#
------------

1) Add methods to increase the time period for the ERS1 satellite and to set custom and access display intervals:

		public void EnlargeTimePeriod()
		{
			//Increase the time period of the ERS1 satellite from
			//4 hrs to 24 hrs
			try
			{
				IAgVePropagatorJ4Perturbation j4 = (IAgVePropagatorJ4Perturbation)ers1.Propagator;
				j4.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000", "2 Jul 2002 00:00:00.000");
				j4.Propagate();
				root.Rewind();
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}

		public void CustomDisplayIntervals()
		{
			//Define 2 time intervals in which the graphics display
			//of ERS1's ground and orbit tracks is altered
			try
			{
				ers1.Graphics.SetAttributesType(AgEVeGfxAttributes.
					eAttributesCustom);
				IAgVeGfxAttributesCustom customAtt = (IAgVeGfxAttributesCustom)ers1.Graphics.Attributes;

				//First Interval: 1/2 hour before noon
				//Color the tracks red and make the line thicker
				IAgVeGfxInterval gfxInterval = customAtt.Intervals.Add("1 Jul 2002 11:30:00.000", "1 Jul 2002 12:00:00.000");
				gfxInterval.GfxAttributes.Color = System.Drawing.Color.Red;
				gfxInterval.GfxAttributes.IsVisible = true;
				gfxInterval.GfxAttributes.Inherit= true;
				gfxInterval.GfxAttributes.Line.Width = AgELineWidth.e3;

				//Second Interval: 1/2 hour before midnight
				//Color the tracks blue and make the line thicker
				gfxInterval = customAtt.Intervals.Add("1 Jul 2002 23:30:00.000", "1 Jul 2002 24:00:00.000");
				gfxInterval.GfxAttributes.Color = System.Drawing.Color.Blue;
				gfxInterval.GfxAttributes.IsVisible = true;
				gfxInterval.GfxAttributes.Inherit = true;
				gfxInterval.GfxAttributes.Line.Width = AgELineWidth.e3;
				root.Rewind();
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}

		public void AccessDisplayIntervals()
		{
			//Configure the display of ERS1 and the Horizon sensor
			//to occur only during access to a facility
			try
			{
				//Assign the 5 facilities as access objects for ERS1
				ers1.Graphics.SetAttributesType(AgEVeGfxAttributes.
					eAttributesAccess);
				IAgVeGfxAttributesAccess gfxAccess = (IAgVeGfxAttributesAccess)ers1.Graphics.Attributes;
				gfxAccess.AccessObjects.Add("Facility/Wallops");
				gfxAccess.AccessObjects.Add("Facility/Seoul");
				gfxAccess.AccessObjects.Add("Facility/Baikonur");
				gfxAccess.AccessObjects.Add("Facility/Perth");
				gfxAccess.AccessObjects.Add(((IAgStkObject)whitesands).Path);

				//Set ERS1's display properties for periods during
				//which there is no access to any facility
				IAgVeGfxAttributesOrbit orbitGfx = (IAgVeGfxAttributesOrbit)gfxAccess.NoAccess;
				orbitGfx.IsVisible = true;
				orbitGfx.Inherit = false;
				orbitGfx.IsGroundMarkerVisible = false;
				orbitGfx.IsOrbitMarkerVisible = false;

				//Set up the Horizon sensor to display only when
				//it has access to a facility
				IAgDisplayTm horizonDispTm = (IAgDisplayTm)horizon;
				horizonDispTm.SetDisplayStatusType(AgEDisplayTimesType.
					eDuringAccess);
				IAgDuringAccess duringAccess = (IAgDuringAccess)horizonDispTm.DisplayTimesData;
				IAgObjectLinkCollection accessObjects = duringAccess.AccessObjects;
				accessObjects.Add("Facility/Wallops");
				accessObjects.Add("Facility/Seoul");
				accessObjects.Add("Facility/Baikonur");
				accessObjects.AddObject((IAgStkObject)perth);
				accessObjects.Add(((IAgStkObject)whitesands).Path);
				root.Rewind();
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}


2) Add the following else-if blocks to the SelectedIndexChanged() method for the combo box:

			else if (action == "Enlarge Time Period")
			{
				EnlargeTimePeriod();
			}
			else if (action == "Custom Display Intervals")
			{
				CustomDisplayIntervals();
			}
			else if(action == "Access Display Intervals")
			{
				AccessDisplayIntervals();
			}
			
			
LANGUAGE: VB.NET
----------------

1) Add methods to increase the time period for the ERS1 satellite and to set custom and access display intervals:

    Public Sub EnlargeTimePeriod()
        'Increase the time period of the ERS1 satellite from
        '4 hrs to 24 hrs
        Try
            Dim j4 As IAgVePropagatorJ4Perturbation = CType(ers1.Propagator, IAgVePropagatorJ4Perturbation)
            j4.EphemerisInterval.SetStartAndStopTimes("1 Jul 2002 00:00:00.000","2 Jul 2002 00:00:00.000")
            j4.Propagate()
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'EnlargeTimePeriod

    Public Sub CustomDisplayIntervals()
        'Define 2 time intervals in which the graphics display
        'of ERS1's ground and orbit tracks is altered
        Try
            ers1.Graphics.SetAttributesType(AgEVeGfxAttributes.eAttributesCustom)
            Dim customAtt As IAgVeGfxAttributesCustom = CType(ers1.Graphics.Attributes, IAgVeGfxAttributesCustom)

            'First Interval: 1/2 hour before noon
            'Color the tracks red and make the line thicker
            Dim gfxInterval As IAgVeGfxInterval = customAtt.Intervals.Add("1 Jul 2002 11:30:00.000", "1 Jul 2002 12:00:00.000")
            gfxInterval.GfxAttributes.Color = System.Drawing.Color.Red
            gfxInterval.GfxAttributes.IsVisible = True
            gfxInterval.GfxAttributes.Inherit = True
            gfxInterval.GfxAttributes.Line.Width = AgELineWidth.e3

            'Second Interval: 1/2 hour before midnight
            'Color the tracks blue and make the line thicker
            gfxInterval = customAtt.Intervals.Add("1 Jul 2002 23:30:00.000", "1 Jul 2002 24:00:00.000")
            gfxInterval.GfxAttributes.Color = System.Drawing.Color.Blue
            gfxInterval.GfxAttributes.IsVisible = True
            gfxInterval.GfxAttributes.Inherit = True
            gfxInterval.GfxAttributes.Line.Width = AgELineWidth.e3
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'CustomDisplayIntervals

    Public Sub AccessDisplayIntervals()
        'Configure the display of ERS1 and the Horizon sensor
        'to occur only during access to a facility
        Try
            'Assign the 5 facilities as access objects for ERS1
            ers1.Graphics.SetAttributesType(AgEVeGfxAttributes.eAttributesAccess)
            Dim gfxAccess As IAgVeGfxAttributesAccess = CType(ers1.Graphics.Attributes, IAgVeGfxAttributesAccess)
            gfxAccess.AccessObjects.Add("Facility/Wallops")
            gfxAccess.AccessObjects.Add("Facility/Seoul")
            gfxAccess.AccessObjects.Add("Facility/Baikonur")
            gfxAccess.AccessObjects.Add("Facility/Perth")
            gfxAccess.AccessObjects.Add(CType(whitesands, IAgStkObject).Path)

            'Set ERS1's display properties for periods during
            'which there is no access to any facility
            Dim orbitGfx As IAgVeGfxAttributesOrbit = CType(gfxAccess.NoAccess, IAgVeGfxAttributesOrbit)
            orbitGfx.IsVisible = True
            orbitGfx.Inherit = False
            orbitGfx.IsGroundMarkerVisible = False
            orbitGfx.IsOrbitMarkerVisible = False

            'Set up the Horizon sensor to display only when
            'it has access to a facility
            Dim horizonDispTm As IAgDisplayTm = CType(horizon, IAgDisplayTm)
            horizonDispTm.SetDisplayStatusType(AgEDisplayTimesType.eDuringAccess)
            Dim duringAccess As IAgDuringAccess = CType(horizonDispTm.DisplayTimesData, IAgDuringAccess)
            Dim accessObjects As IAgObjectLinkCollection = duringAccess.AccessObjects
            accessObjects.Add("Facility/Wallops")
            accessObjects.Add("Facility/Seoul")
            accessObjects.Add("Facility/Baikonur")
            accessObjects.AddObject(CType(perth, IAgStkObject))
            accessObjects.Add(CType(whitesands, IAgStkObject).Path)
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'AccessDisplayIntervals


2) Add the following cases to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Enlarge Time Period"
                EnlargeTimePeriod()
            Case "Custom Display Intervals"
                CustomDisplayIntervals()
            Case "Access Display Intervals"
                AccessDisplayIntervals()
			
			
* --------------------------------- *
* SECTION: Apply Access Constraints *
* --------------------------------- *

LANGUAGE: C#
------------

1) Add methods to compute sensor-to-facility access and impose 2 access constraints:

		public void FacilityAccess()
		{
			//Compute access from the Horizon sensor to Baikonur
			try
			{
				access = ((IAgStkObject)horizon).GetAccessToObject((IAgStkObject)baikonur);
				access.ComputeAccess();
				root.Rewind();
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}

		public void AccessConstraintsRange()
		{
			//Constrain access from the Horizon sensor to Baikonur to
			//occur only when the distance between them <= 2000 km
			try
			{
				IAgAccessCnstrMinMax minMax = (IAgAccessCnstrMinMax)horizon.AccessConstraints.
					AddConstraint(AgEAccessConstraints.eCstrRange);

				minMax.EnableMax = true;
				minMax.Max = 2000;

				// Experiment with other values by uncommenting one
				// or more of the following lines:
				// minMax.Max = 1500;
				// minMax.Max = 1000;
				// minMax.Max = 500;
				root.Rewind();
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}

		public void AccessConstraintsSunElevationAngle()
		{
			//Constrain access from the Horizon sensor to Baikonur to
			//occur only when the elevation angle to the apparent 
			//position of the sun >= 15 deg
			try
			{
				IAgAccessCnstrMinMax minMax = (IAgAccessCnstrMinMax)horizon.AccessConstraints.
					AddConstraint(AgEAccessConstraints.eCstrSunElevationAngle);
				minMax.EnableMin = true;
				minMax.Min = 15;
				// Experiment with other values by uncommenting one
				// or more of the following lines:
				// minMax.Min = 10;
				// minMax.Min = 5;
				// minMax.Min = 20;

				this.root.Rewind();
			}
			catch(Exception e)
			{
				MessageBox.Show(e.Message);
			}
		}


2) Add the following else-if blocks to the SelectedIndexChanged() method for the combo box:

			else if(action == "Facility Access")
			{
				FacilityAccess();
			}
			else if(action == "SunElevationAngle Constraint")
			{
				AccessConstraintsSunElevationAngle();
			}
			else if(action == "Range Constraint")
			{
				AccessConstraintsRange();
			}


LANGUAGE: VB.NET
----------------

1) Add methods to compute sensor-to-facility access and impose 2 access constraints:

    Public Sub FacilityAccess()
        'Compute access from the Horizon sensor to Baikonur
        Try
            access = CType(horizon, IAgStkObject).GetAccessToObject(CType(baikonur, IAgStkObject))
            access.ComputeAccess()
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'FacilityAccess

    Public Sub AccessConstraintsRange()
        'Constrain access from the Horizon sensor to Baikonur to
        'occur only when the distance between them <= 2000 km
        Try
            Dim minMax As IAgAccessCnstrMinMax = CType(horizon.AccessConstraints.AddConstraint(AgEAccessConstraints.eCstrRange), IAgAccessCnstrMinMax)

            minMax.EnableMax = True
            minMax.Max = 2000

            ' Experiment with other values by uncommenting one
            ' or more of the following lines:
            ' minMax.Max = 1500;
            ' minMax.Max = 1000;
            ' minMax.Max = 500;
            root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'AccessConstraintsRange

    Public Sub AccessConstraintsSunElevationAngle()
        'Constrain access from the Horizon sensor to Baikonur to
        'occur only when the elevation angle to the apparent 
        'position of the sun >= 15 deg
        Try
            Dim minMax As IAgAccessCnstrMinMax = CType(horizon.AccessConstraints.AddConstraint(AgEAccessConstraints.eCstrSunElevationAngle), IAgAccessCnstrMinMax)
            minMax.EnableMin = True
            minMax.Min = 15
            ' Experiment with other values by uncommenting one
            ' or more of the following lines:
            ' minMax.Min = 10
            ' minMax.Min = 5
            ' minMax.Min = 20
            Me.root.Rewind()
        Catch e As Exception
            MessageBox.Show(e.Message)
        End Try
    End Sub 'AccessConstraintsSunElevationAngle


2) Add the following cases to the Select Case block in the SelectedIndexChanged() method for the combo box:

            Case "Facility Access"
                FacilityAccess()
            Case "SunElevationAngle Constraint"
                AccessConstraintsSunElevationAngle()
            Case "Range Constraint"
                AccessConstraintsRange()