/// <summary>
/// Creates a new instance of our transmitting phone
/// with default configuration and graphics.
/// </summary>
/// <returns>A new SimpleDigitalTransmitter.</returns>
private SimpleDigitalTransmitter CreateTransmittingPhone()
{
var earth = CentralBodiesFacet.GetFromContext().Earth;
// Create a new SimpleDigitalTransmitter and assign its basic properties.
// Even though we are using a static location for our transmitter,
// it can easily be changed to a moving one by simply modifying the
// LocationPoint to something else, for example a route generated
// with the Route Design Library.
double longitude = Trig.DegreesToRadians(39.6333);
double latitude = Trig.DegreesToRadians(11.1333);
var phone = new SimpleDigitalTransmitter
{
Name = "Dessie, Ethiopia",
LocationPoint = new PointCartographic(earth, new Cartographic(longitude, latitude, 0.0)),
CarrierFrequency = m_intendedSignal.TargetFrequency,
EffectiveIsotropicRadiatedPower = CommunicationAnalysis.FromDecibels(m_transmitPowerTrackBar.Value),
DataRate = 50000.0
};
//Add a default marker
phone.Extensions.Add(new MarkerGraphicsExtension(new MarkerGraphics
{
Texture = new ConstantGraphicsParameter <Texture2D>(m_phoneTexture)
}));
//Add a label based on the name and show just below the marker.
var textGraphics = new TextGraphics
{
Color = new ConstantGraphicsParameter <Color>(Color.Yellow),
Font = new ConstantGraphicsParameter <Font>(m_labelFont),
Outline = new ConstantGraphicsParameter <bool>(true),
OutlineColor = new ConstantGraphicsParameter <Color>(Color.Black),
Text = new ConstantGraphicsParameter <string>(phone.Name),
Origin = new ConstantGraphicsParameter <Origin>(Origin.TopCenter),
PixelOffset = new ConstantGraphicsParameter <PointF>(new PointF(0, -m_phoneTexture.Template.Height / 2)),
DisplayParameters =
{
MaximumDistance = new ConstantGraphicsParameter <double>(75000000.0)
}
};
if (TextureFilter2D.Supported(TextureWrap.ClampToEdge))
{
textGraphics.TextureFilter = new ConstantGraphicsParameter <TextureFilter2D>(TextureFilter2D.NearestClampToEdge);
}
phone.Extensions.Add(new TextGraphicsExtension(textGraphics));
return(phone);
}
/// <summary>
/// "Places" the call by enabling the display of
/// the link budget results as well as showing a line
/// indicating if the link is currently valid. If links
/// signal to noise ratio gets to high, it becomes invalid
/// and the line disappears.
/// </summary>
private void OnPlaceCallClick(object sender, EventArgs e)
{
m_callPlaced = true;
m_placeCallButton.Enabled = false;
m_hangUpButton.Enabled = true;
m_transmitPowerTrackBar.Enabled = false;
m_linkBudgetOverlayHelper.Overlay.Display = true;
// We want to draw link lines representing the link, but we don't want to draw the
// lines unless the signal quality is acceptable. We already configured the
// link itself to take the curvature of the earth into account to ensure line
// of sight for our assets. The next step is to choice an acceptable signal
// quality. Below we create an AccessQuery that is only valid when the
// carrier to noise ratio of the final downlink is over -16 dB.
// We then pass this query to UpdateLinkGraphics which will use it to
// configure the Display property of the link graphics. Finally, we call
// ApplyChanges to update the display.
var linkBudgetScalars = m_communicationSystem.GetLinkBudgetScalars(m_iridium4ToReceiverDownLink, m_intendedSignal);
AccessQuery query = new ScalarConstraint(linkBudgetScalars.CarrierToNoise, CommunicationAnalysis.FromDecibels(-16.0));
UpdateLinkGraphics(m_callerToIridium49UpLink, query);
UpdateLinkGraphics(m_iridium4ToReceiverDownLink, query);
UpdateLinkGraphics(m_iridium49To58Crosslink, query);
UpdateLinkGraphics(m_iridium58To4Crosslink, query);
m_display.ApplyChanges();
// Manually fire the combo box change event in order to
// properly initialize the link budget overlay.
OnLinkComboBoxSelectedIndexChanged(this, EventArgs.Empty);
// Start animation if it's not going.
if (!SceneManager.Animation.IsAnimating)
{
SceneManager.Animation.PlayForward();
}
}
/// <summary>
/// We allow the user to modify the transmission power via a track bar. Whenever it is changed,
/// assign the new power. This does not affect anything until until we create new evaluators.
/// </summary>
private void OnTransmitPowerValueChanged(object sender, EventArgs e)
{
m_transmittingPhone.EffectiveIsotropicRadiatedPower = CommunicationAnalysis.FromDecibels(m_transmitPowerTrackBar.Value);
}
private void btnCalculate_Click(object sender, EventArgs e)
{
textBox1.Clear();
// determine the user's selected receiver type
GpsSignalConfiguration selectedReceiver = GetSelectedReceiver();
// create a GPS Comm front end
var frontEnd = new GpsCommunicationsFrontEnd(m_gpsConstellation, selectedReceiver, m_location, m_orientation)
{
// set the front end's epoch - essentially when it starts receiving signals
Epoch = m_analysisTime
};
// apply the front end to the receiver's Antenna property
m_receiver.Antenna = frontEnd;
// create a new communications-based noise model for the receiver
m_receiver.NoiseModel = new GpsCommunicationsNoiseModel(frontEnd);
// Jammer location - 10 km directly above the receiver
var jammerLocationPoint = new PointFixedOffset(frontEnd.ReferenceFrame, new Cartesian(0, 0, 10000));
if (cbL1Jammer.Checked)
{
// 1 watt, narrow band jammer centered at L1
// increase to 10 watts to see a more dramatic effect
// adds interferers to the front end's internal CommunicationSystem
frontEnd.InterferingSources.Add(new SimpleAnalogTransmitter("L1Jammer", jammerLocationPoint, 1575.42e6, 1.0, 1.023e6));
}
if (cbL2Jammer.Checked)
{
// 1 watt, narrow band jammer centered at L2
frontEnd.InterferingSources.Add(new SimpleAnalogTransmitter("L2Jammer", jammerLocationPoint, 1227.6e6, 1.0, 1.023e6));
}
if (cbL5Jammer.Checked)
{
// 1 watt, narrow band jammer centered at L5
frontEnd.InterferingSources.Add(new SimpleAnalogTransmitter("L5Jammer", jammerLocationPoint, 1176.45e6, 1.0, 1.023e6));
}
var builder = new StringBuilder();
// get an evaluator for the receiver that reports which satellites are tracked
// we could get the standard DilutionOfPrecision, AssessedNavigationAccuracy or PredictedNavigationAccuracy
// evaluators here as well.
PlatformCollection trackedSatellites;
using (var satelliteTrackingEvaluator = m_receiver.GetSatelliteTrackingEvaluator())
{
// evaluate the satellite tracking evaluator at a single time
trackedSatellites = satelliteTrackingEvaluator.Evaluate(m_analysisTime);
}
builder.AppendFormat("{0} SVs tracked", trackedSatellites.Count)
.AppendLine();
var prnsTracked = new List <int>();
if (trackedSatellites.Count > 0)
{
// create the link budget scalars by hand for just the tracked SVs.
// we'll use the link budgets we received from the front end later
// this section shows how to create them from scratch if necessary
// get the propagation graph from the front end
var graph = frontEnd.GetFrontEndSignalPropagationGraph();
foreach (var satellite in trackedSatellites)
{
int prn = ServiceHelper.GetService <IGpsPrnService>(satellite).PseudoRandomNumber;
prnsTracked.Add(prn);
var satelliteInformation = ServiceHelper.GetService <IGpsSatelliteInformationService>(satellite).Information;
builder.AppendFormat("SVN {0}, PRN {1}, Block: {2}", satelliteInformation.SatelliteVehicleNumber, prn, satelliteInformation.Block)
.AppendLine();
var receiverChannels = frontEnd.GetReceiverChannels();
if (receiverChannels.ContainsSatelliteID(prn))
{
// gets the first channel in the receiver tracking the specified PRN.
// there should only be one.
var channel = receiverChannels.FindFirst(prn);
// get the link for the primary signal on that channel
var linkService = ServiceHelper.GetService <ILinkService>(channel.FindFirst(NavigationSignalPriority.Primary).ChannelLink);
var primarySignalReceiver = linkService.Receiver;
// use the transmitter on that link to identify the proper signal to analyze
var strategy = new IntendedSignalByTransmitter(linkService.Transmitter);
// create the desired scalars
if (cbOutputCNI.Checked)
{
var scalar = new ScalarCarrierToNoiseDensityPlusInterference(primarySignalReceiver, graph, strategy);
using (var evaluator = scalar.GetEvaluator())
{
builder.AppendFormat("C/(N0+I): {0:F5} dB-Hz", CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime)))
.AppendLine();
}
}
if (cbOutputJS.Checked)
{
var scalar = new ScalarJammingToSignal(primarySignalReceiver, graph, strategy);
using (var evaluator = scalar.GetEvaluator())
{
builder.AppendFormat("J/S: {0:F5} dB", Math.Abs(CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime))))
.AppendLine();
}
}
if (cbOutputNI.Checked)
{
var scalar = new ScalarNoisePlusInterference(linkService.Receiver, graph, strategy);
using (var evaluator = scalar.GetEvaluator())
{
builder.AppendFormat("N+I: {0:F5} dB", CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime)))
.AppendLine();
}
}
if (cbOutputRcvrNoise.Checked)
{
var scalar = new ScalarGpsCommunicationsReceiverChannelNoise(m_receiver, prn);
using (var evaluator = scalar.GetEvaluator())
{
builder.AppendFormat("Receiver Noise: {0:F5} meters", evaluator.Evaluate(m_analysisTime))
.AppendLine();
}
}
}
else
{
MessageBox.Show("No Channel tracking that PRN!");
}
}
}
// Use the link budgets provided by the front-end.
// Note that GpsReceiver noise is not a LinkBudget parameter.
foreach (var linkBudgetScalars in frontEnd.GetAllLinkBudgets(m_receiver))
{
if (cbForTrackedSVsOnly.Checked)
{
if (prnsTracked.Contains(linkBudgetScalars.SatelliteID))
{
if (cbOutputCNI.Checked)
{
using (var evaluator = linkBudgetScalars.CarrierToNoiseDensityPlusInterference.GetEvaluator())
{
builder.AppendFormat("C/(N0+I) for PRN {0}, on {1}: {2:F5} dB-Hz",
linkBudgetScalars.SatelliteID, linkBudgetScalars.SignalType, CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime)))
.AppendLine();
}
}
if (cbOutputJS.Checked)
{
using (var evaluator = linkBudgetScalars.JammingToSignal.GetEvaluator())
{
builder.AppendFormat("J/S for PRN {0}, on {1}: {2:F5} dB",
linkBudgetScalars.SatelliteID, linkBudgetScalars.SignalType, Math.Abs(CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime))))
.AppendLine();
}
}
if (cbOutputNI.Checked)
{
using (var evaluator = linkBudgetScalars.NoisePlusInterference.GetEvaluator())
{
builder.AppendFormat("N+I for PRN {0}, on {1}: {2:F5} dB",
linkBudgetScalars.SatelliteID, linkBudgetScalars.SignalType, CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime)))
.AppendLine();
}
}
}
}
else
{
if (cbOutputCNI.Checked)
{
using (var evaluator = linkBudgetScalars.CarrierToNoiseDensityPlusInterference.GetEvaluator())
{
builder.AppendFormat("C/(N0+I) for PRN {0}, on {1}: {2:F5} dB-Hz",
linkBudgetScalars.SatelliteID, linkBudgetScalars.SignalType, CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime)))
.AppendLine();
}
}
if (cbOutputJS.Checked)
{
using (var evaluator = linkBudgetScalars.JammingToSignal.GetEvaluator())
{
builder.AppendFormat("J/S for PRN {0}, on {1}: {2:F5} dB",
linkBudgetScalars.SatelliteID, linkBudgetScalars.SignalType, Math.Abs(CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime))))
.AppendLine();
}
}
if (cbOutputNI.Checked)
{
using (var evaluator = linkBudgetScalars.NoisePlusInterference.GetEvaluator())
{
builder.AppendFormat("N+I for PRN {0}, on {1}: {2:F5} dB",
linkBudgetScalars.SatelliteID, linkBudgetScalars.SignalType, CommunicationAnalysis.ToDecibels(evaluator.Evaluate(m_analysisTime)))
.AppendLine();
}
}
}
}
textBox1.Text = builder.ToString();
}