//#####################################################################
/// <summary>
/// 根据星历表,创建新的PathPrimitive</para>
/// </summary>
/// <param name="ephemeris">卫星星历数据</param>
/// <param name="frame">参考系</param>
public static PathPrimitive CreatePathPrimitiveFromEphemeris(DateMotionCollection <Cartesian> ephemeris, ReferenceFrame frame)
{
try
{
List <PathPoint> points = new List <PathPoint>();
for (int i = 0; i < ephemeris.Count; i++)
{
points.Add(new PathPointBuilder(ephemeris.Values[i], ephemeris.Dates[i], Color.Yellow).ToPathPoint());
}
PathPrimitive pathPrimitive = new PathPrimitive();
//pathPrimitive.UpdatePolicy = new DurationPathPrimitiveUpdatePolicy(new Duration(0, 60), PathPrimitiveRemoveLocation.RemoveLocationFront);
pathPrimitive.ReferenceFrame = frame;
//pathPrimitive.AddRangeToFront(points);
pathPrimitive.AddRangeToBack(points);
pathPrimitive.Width = 3.0F;
SceneManager.Animation.Time = ephemeris.Dates[0];
return(pathPrimitive);
}
catch (Exception ex)
{
throw new Exception(ex.Message + "\n" + "向3D图中画卫星轨迹出错!");
}
}
//#########################################################################################
/// <summary>
/// 由T0时刻初始状态,积分dt后的状态,返回最后的状态
/// </summary>
/// <param name="dT">积分时长(s)</param>
/// <returns>最后时间点位置、速度</returns>
public Motion <Cartesian> Propagate(double dT)
{
// 数据初始化
EphemerisData = new DateMotionCollection <Cartesian>();
//归一化
UnitL = 1.0;
UnitT = 1.0;
UnitV = 1.0;
Step = InitialStepsize; //初始步长
if (IsNormalize)
{
UnitL = Re;
UnitT = Math.Sqrt(UnitL * UnitL * UnitL / Mu);
UnitV = UnitL / UnitT;
Step = InitialStepsize / UnitT; // 初始步长
}
//设置微分方程自变量X[]
double[] x = new double[6] {
InitialCondition.Value.X / UnitL,
InitialCondition.Value.Y / UnitL,
InitialCondition.Value.Z / UnitL,
InitialCondition.FirstDerivative.X / UnitV,
InitialCondition.FirstDerivative.Y / UnitV,
InitialCondition.FirstDerivative.Z / UnitV
};
// 数值积分
SolveDt(T0 / UnitT, (T0 + dT) / UnitT, x);
// 返回最后时间点位置、速度
return(new Motion <Cartesian>(EphemerisData.Values.Last(), EphemerisData.FirstDerivatives.Last()));
}
/// <summary>
/// Propagate a Platform using a NumericalPropagator configured with the entered KeplerianElements,
/// ForceModels, NumericalIntegrator, and start and stop dates.
/// </summary>
private void PropagateSatellite()
{
KeplerianElements orbitalElements = m_keplerianOrbitalElementsEntry.KeplerianElementValues;
if (orbitalElements == null)
{
return;
}
Motion <Cartesian> initialMotion = orbitalElements.ToCartesian();
PropagationNewtonianPoint point = new PropagationNewtonianPoint(m_elementID, m_forceModelSettings.CurrentCentralBody.InertialFrame, initialMotion.Value, initialMotion.FirstDerivative);
point.Mass = new ScalarFixed(double.Parse(m_mass.Text));
m_forceModelSettings.SetForceModelsOnPoint(point, new ScalarFixed(double.Parse(m_area.Text)));
CentralBody primaryCentralBody = m_forceModelSettings.CurrentCentralBody;
NumericalPropagatorDefinition state = new NumericalPropagatorDefinition();
state.IntegrationElements.Add(point);
state.Integrator = m_integratorSettings.GetIntegrator();
JulianDate start = new JulianDate(GregorianDate.ParseExact(m_start.Text, DateFormat, null));
JulianDate end = new JulianDate(GregorianDate.ParseExact(m_end.Text, DateFormat, null));
state.Epoch = start;
NumericalPropagator propagator = state.CreatePropagator();
propagator.StepTaken += (sender, args) =>
{
// Telling the propagator to stop if we get too close to the central body
Cartesian position = propagator.Converter.ConvertState <Cartesian>(m_elementID, args.CurrentState).Value;
if (position.Magnitude <= primaryCentralBody.Shape.SemimajorAxisLength + 10000)
{
args.Indication = PropagationEventIndication.StopPropagationAfterStep;
}
};
DateMotionCollection <Cartesian> answer = null;
var backgroundCalculation = new BackgroundCalculation();
backgroundCalculation.DoWork += (sender, e) =>
{
// actually propagate
var result = propagator.Propagate(end.Subtract(start), 1, backgroundCalculation);
answer = result.GetDateMotionCollection <Cartesian>(m_elementID);
};
backgroundCalculation.ProgressChanged += (sender, e) => m_propagationProgress.Value = e.ProgressPercentage;
backgroundCalculation.RunWorkerCompleted += (sender, e) =>
{
// when finished, draw the satellite
DrawSatellite(answer, primaryCentralBody.InertialFrame);
m_propagate.Enabled = true;
};
m_propagate.Enabled = false;
backgroundCalculation.RunWorkerAsync();
}
/// <summary>
/// Draw the ephemeris in the Insight3D window.
/// </summary>
/// <param name="ephemeris">The date, position (and velocity) information of the object being displayed.</param>
/// <param name="inertialFrame">The inertial frame to display the graphics in.</param>
private void DrawSatellite(DateMotionCollection <Cartesian> ephemeris, ReferenceFrame inertialFrame)
{
// Clean up the previous run's graphics
foreach (Primitive primitive in m_primitivesAddedToScene)
{
SceneManager.Primitives.Remove(primitive);
}
m_primitivesAddedToScene.Clear();
if (m_platform != null)
{
m_display.ServiceProviders.Remove(m_platform);
}
// Draw the orbit
List <PathPoint> points = new List <PathPoint>();
for (int i = 0; i < ephemeris.Count; i++)
{
points.Add(new PathPointBuilder(ephemeris.Values[i], ephemeris.Dates[i]).ToPathPoint());
}
PathPrimitive path = new PathPrimitive {
ReferenceFrame = inertialFrame
};
path.AddRangeToFront(points);
SceneManager.Primitives.Add(path);
m_primitivesAddedToScene.Add(path);
// Put a marker where the satellite is at a given time
LagrangePolynomialApproximation interpolationAlgorithm = new LagrangePolynomialApproximation();
TranslationalMotionInterpolator interpolator = new TranslationalMotionInterpolator(interpolationAlgorithm, 2, ephemeris);
m_platform = new Platform
{
LocationPoint = new PointInterpolator(inertialFrame, interpolator)
};
Texture2D texture = SceneManager.Textures.FromUri(@"Data\Markers\Satellite.png");
m_platform.Extensions.Add(new MarkerGraphicsExtension(new MarkerGraphics
{
Texture = new ConstantGraphicsParameter <Texture2D>(texture)
}));
m_display.ServiceProviders.Add(m_platform);
m_display.ApplyChanges();
// Set the date to the start of the ephemeris
SceneManager.Animation.Time = ephemeris.Dates[0];
}
/// <summary>
/// 从Table表中，创建新的PathPrimitive
/// <para>表中提供的位置、速度要与参考系一致</para>
/// </summary>
/// <param name="dt">表名</param>
/// <param name="colNames">表列名称(t,x,y,z,Vx,Vy,Vz)</param>
/// <param name="frame">坐标系</param>
/// <returns></returns>
public static PathPrimitive CreatePathPrimitiveFromTable(DataTable dt, JulianDate jd0, string[] colNames, ReferenceFrame frame)
{
try
{
DateMotionCollection <Cartesian> ephemeris = new DateMotionCollection <Cartesian> ();
//将Table中的相应参数读入
JulianDate jd;
Cartesian R, V;
foreach (DataRow dr in dt.Rows)
{
jd = jd0.AddSeconds((double)dr[colNames[0]]);
R = new Cartesian((double)dr[colNames[1]], (double)dr[colNames[2]], (double)dr[colNames[3]]);
V = new Cartesian((double)dr[colNames[4]], (double)dr[colNames[5]], (double)dr[colNames[6]]);
ephemeris.Add(jd, R, V);
}
return(CreatePathPrimitiveFromEphemeris(ephemeris, frame));
}
catch (Exception ex)
{
throw new Exception(ex.Message + "\n" + "从Table中创建PathPrimitive出错！");
}
}
/// <summary>
/// Method to export ephemeris to STK .e file
/// </summary>
#region ExportEphemeris
private void OnExportEphemerisClick(object sender, EventArgs e)
{
// Open the almanac file
SemAlmanac almanac;
using (Stream stream = openAlmanacDialog.OpenFile())
using (StreamReader reader = new StreamReader(stream))
{
almanac = SemAlmanac.ReadFrom(reader, 1);
}
// setup the progressbar
// GPSElement contains a list of PRNs (PRNList) available in the almanac.
progressBar1.Maximum = almanac.Count;
progressBar1.Step = 1;
// get just the almanac path here. This will allow us to place the new .e files in the same place the almanac was opened from.
string outputPath = Path.GetDirectoryName(openAlmanacDialog.FileName);
// Create a .e file for every PRN in the element set...
foreach (SemAlmanacRecord record in almanac)
{
// provide a name and path for the new .e file.
string filename = String.Format("PRN_{0:00}.e", record.PseudoRandomNumber);
string path = outputPath + "\\" + filename;
// check that the path exists
if (File.Exists(path))
{
// ask if it's OK to overwrite existing files. If it's not, advance the progress bar (passed this SV) and continue to the next SV
if (MessageBox.Show(string.Format("{0} " + Localization.existsOverwrite, filename), Localization.FileExists, MessageBoxButtons.YesNo) == DialogResult.No)
{
progressBar1.PerformStep();
continue;
}
}
// ok to overwrite existing files (or no file existed already)
// the using block here will use the sw variable to write the .e file stream to.
using (StreamWriter writer = File.CreateText(path))
{
JulianDate startjd;
JulianDate stopjd;
// We need to know which time standard to use here. if the user has specified that GPS time is to be used
// we need to create the JulianDates with the GlobalPositioningSystemTime standard.
if (GPSTimeRadio.Checked)
{
startjd = new JulianDate(StartTime.Value, TimeStandard.GlobalPositioningSystemTime);
stopjd = new JulianDate(StopTime.Value, TimeStandard.GlobalPositioningSystemTime);
}
else
{
// otherwise, the default time standard is UTC
startjd = new JulianDate(StartTime.Value);
stopjd = new JulianDate(StopTime.Value);
}
// Now that we know the start and stop times for the .e file, we need to propagate the orbits
// the NavstarISGps200DPropagator take a Duration type for the timestep - let's create it
// using the user-specified timestep value
double timestep = double.Parse(TimeStep.Text);
Duration timestepDuration = Duration.FromSeconds(timestep);
// declare a NavstarISGps200DPropagator - this is used to propagate the satellite positions
// assign an instance of the propagator. The propagator constructor takes an almanac element set (for a single satellite)
NavstarISGps200DPropagator propagator = new NavstarISGps200DPropagator(record);
// now create an StkEphemerisFile object and assign its Ephemeris property the output of the propagator
StkEphemerisFile file = new StkEphemerisFile();
DateMotionCollection <Cartesian> ephemeris = propagator.Propagate(startjd, stopjd, timestepDuration, 0, propagator.ReferenceFrame);
StkEphemerisFile.EphemerisTimePos ephemerisFormat = new StkEphemerisFile.EphemerisTimePos
{
CoordinateSystem = propagator.ReferenceFrame,
EphemerisData = ephemeris
};
file.Data = ephemerisFormat;
// write the .e ephemeris to the stream opened in this using block
file.WriteTo(writer);
} // end of using block
// update the progress bar
progressBar1.PerformStep();
} // end of PRN List
// we're done! Reset the progress bar
progressBar1.Value = 0;
}
