public override void CalculateTransmissionLoss(Platform platform, Mode mode, Radial radial, BottomProfile bottomProfile, SedimentType sedimentType, double windSpeed, IList<Tuple<double, SoundSpeedProfile>> soundSpeedProfilesAlongRadial)
{
var sourceDepth = platform.Depth;
var frequency = (float)Math.Sqrt(mode.HighFrequency * mode.LowFrequency);
if (mode.Depth.HasValue) sourceDepth += mode.Depth.Value;
var directoryPath = Path.GetDirectoryName(radial.BasePath);
if (directoryPath == null) throw new NullReferenceException("radial.BasePath does not point to a valid directory");
if (!Directory.Exists(directoryPath)) Directory.CreateDirectory(directoryPath);
// Derived Parameters
// ==================
// Note: All the specific calculations given in the comments below assume a frequency of 1kHz
// lambda is wavelength, in meters
var lambda = ReferenceSoundSpeed / frequency;
// if dz < 1m round dz down to either [1/10, 1/5, 1/4 or 1/2] m ... or multiples of 10^-n of these numbers
// = [1 2 2.5 or 5 ] x 0.1m " " ...
// if dz > 1m round dz down to either [1 2 2.5 5 ] m ... or multiples of 10^+n of these numbers
// var fixpoints = new List<double> { 1, 2, 2.5, 5 };
// dz = 0.1 * lambda
var dz = RelativeDepthResolution * lambda;
// make dz a 'pretty' number
//dz = Fix2X10pN(dz, fixpoints);
// ndz is the depth decimation factor
// MinimumOutputDepthResolution is 10m
// dz is 0.1 * lambda (dz = 0.15 for a 1 kHz signal, 'pretty' dz = 0.2 @ 1kHz)
// so ndz = (10 / 0.2) = 50 @ 1kHz
// this means that we will only output every 50 computational depth cells, giving us a depth
// resolution of 50 * 0.2m = 10m @ 1kHz which is what we want it to be. Outstanding.
var ndz = (int)Math.Max(1.0, Math.Floor(MinimumOutputDepthResolution / dz));
// similar for dr and assoc. grid decimation
// RelativeRangeResolution is 2, so with our 'pretty' dz = 0.2, dr = 0.4
var dr = RelativeRangeResolution * dz;
// make dr a 'pretty' number, in this case 0.25
//dr = Fix2X10pN(dr, fixpoints);
// ndr is the range decimation factor
// MinimumOutputRangeResolution is 10m
// dr is 0.25 * lambda, so (10 / 0.25) gives us an ndr of 40
// this means that we will only output every 40 computational range cells, giving us a range
// resolution of 40 * 0.25m = 10m @ 1kHz which is what we want it to be. Outstanding.
var ndr = (int)Math.Max(1, Math.Floor(MinimumOutputRangeResolution / dr));
// attenuation layer (round up to nearest dz)
var sedimentLambda = sedimentType.CompressionWaveSpeed / frequency;
var sedimentLayerDz = Math.Ceiling(LastLayerThickness * sedimentLambda / dz) * dz;
var attenuationLayerDz = Math.Ceiling(AttenuationLayerThickness * sedimentLambda / dz) * dz;
var maxSubstrateDepth = bottomProfile.MaxDepth + sedimentLayerDz;
var zstep = dz * ndz;
var zmplt = Math.Ceiling((bottomProfile.MaxDepth + 2 * zstep) / zstep) * zstep;
// Maximum Depth for PE calc -> zmax
// zmax is the z-limit for the PE calc from top of the water column to the bottom of the last substrate layer
// (including the attentuation layer if, as recommended, this is included)
var zmax = maxSubstrateDepth + attenuationLayerDz;
var envFileName = radial.BasePath + ".env";
//Debug.WriteLine("Scenario: '{0}' Mode: '{2}' Analysis point: {1} Bearing: {3}, zmplt: {4}",
// radial.TransmissionLoss.AnalysisPoint.Scenario.Name,
// radial.TransmissionLoss.AnalysisPoint.Geo,
// radial.TransmissionLoss.Modes[0].ModeName,
// radial.Bearing, zmplt);
using (var envFile = new StreamWriter(envFileName, false))
{
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "Scenario: '{0}' Mode: '{2}' Analysis point: {1} Bearing: {3}",
radial.TransmissionLoss.AnalysisPoint.Scenario.Name,
radial.TransmissionLoss.AnalysisPoint.Geo,
radial.TransmissionLoss.Modes[0].ModeName,
radial.Bearing));
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.000000}\t{1:0.000000}\t{2:0.000000}\t\tf [Frequency (Hz)], zs [Source Depth (m)], zrec0 [First receiever depth (m)]",
frequency,
sourceDepth,
0.1));
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.000000}\t{1:0.000000}\t{2}\t\t\trmax[Max range (m)], dr [Range resolution (m)], ndr [Range grid decimation factor]",
mode.MaxPropagationRadius + (dr * ndr),
dr,
ndr));
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.000000}\t{1:0.000000}\t{2}\t{3:0.000000}\tzmax [Max computational depth (m)], dz [Depth resolution (m)], ndz [Depth grid decimation factor], zmplot [Maximum depth to plot (m)]",
zmax,
dz,
ndz,
zmplt));
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.000000}\t{1}\t{2}\t{3:0.000000}\t\tc0 [Reference sound speed (m/s)], np [Number of terms in Padé expansion], ns [Number of stability constraints], rs [Maximum range of stability constraints (m)]",
ReferenceSoundSpeed,
PadeExpansionTerms,
StabilityConstraints,
StabilityConstraintMaxRange));
// todo: different stuff goes here for RAMSGeo
// bathymetry data
var first = true;
foreach (var profilePoint in bottomProfile.Profile)
{
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture,
"{0:0.000000}\t{1:0.000000}{2}",
profilePoint.Range * 1000,
profilePoint.Depth,
first ? "\t\t\t\t\tbathymetry data [range (m), depth (m)]" : ""));
first = false;
}
envFile.WriteLine("-1\t-1");
// range-dependent environment profiles
var firstRangeProfile = true;
foreach (var rangeProfileTuple in soundSpeedProfilesAlongRadial)
{
// Range of profile only written for second and subsequent profiles
if (!firstRangeProfile) envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.#}\t\t\t\t\t\t\tProfile range (m)", rangeProfileTuple.Item1 * 1000));
var firstSoundSpeedProfile = true;
foreach (var profilePoint in rangeProfileTuple.Item2.Data)
{
if (double.IsNaN(profilePoint.SoundSpeed)) break;
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.######}\t{1:0.######}{2}",
profilePoint.Depth,
profilePoint.SoundSpeed,
firstSoundSpeedProfile ? "\t\t\t\t\tsound speed profile in water [depth (m), sound speed (m/s)]" : ""));
firstSoundSpeedProfile = false;
}
envFile.WriteLine("-1\t-1");
// todo: RAMGeo and RAMSGeo also support sediment layers, as well as range-dependent sediment, neither of which is not yet supported by ESME
// If sediment layers are ever supported, put a loop like for the sound speed profile above
// A sediment layer is analogous to a sound speed profile point
// For range-dependent sediment, the sediment samples have to be at the same ranges as the sound speed profiles
// so we might want to change the API to include sediment properties in what is the current range and sound speed profile tuple
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.######}\t{1:0.######}\t\t\t\t\t\tcompressive sound speed profile in substrate [depth (m), sound speed (m/s)]", 0.0, sedimentType.CompressionWaveSpeed));
envFile.WriteLine("-1\t-1");
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.######}\t{1:0.######}\t\t\t\t\t\tdensity profile in substrate [depth (m), rhob (g/cm³)]", 0.0, sedimentType.Density));
envFile.WriteLine("-1\t-1");
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.######}\t{1:0.######}\t\t\t\t\t\tcompressive attenuation profile in substrate [depth (m), attnp (db/lambda)]", 0.0, 0.0));
envFile.WriteLine(string.Format(CultureInfo.InvariantCulture, "{0:0.######}\t{1:0.######}", attenuationLayerDz, 40));
envFile.WriteLine("-1\t-1");
firstRangeProfile = false;
}
}
var tempDirectory = Path.Combine(Path.GetTempPath(), Path.GetFileNameWithoutExtension(envFileName));
//Debug.WriteLine(string.Format("Env File: {0} temp path: {1}", envFileName, tempDirectory));
if (Directory.Exists(tempDirectory))
{
var files = Directory.GetFiles(tempDirectory, "*.*");
foreach (var file in files) File.Delete(file);
Directory.Delete(tempDirectory, true);
} else if (File.Exists(tempDirectory)) File.Delete(tempDirectory);
Directory.CreateDirectory(tempDirectory);
File.Copy(envFileName, Path.Combine(tempDirectory, "ramgeo.in"));
using (var steerableArrayFile = new StreamWriter(Path.Combine(tempDirectory, "sra.in"), false))
{
// From http://www.activefrance.com/Antennas/Introduction%20to%20Phased%20Array%20Design.pdf
// theta3 = 3dB beam width, in degrees
// emitterSize = size of emitter array, in meters
// theta3 = (0.886 * lambda / arrayLength) * 180 / pi
// so, doing the algebra and solving for arrayLength, you get:
// emitterSize = (0.886 * lambda) / (theta3 * (pi / 180))
var emitterSize = (0.886 * lambda) / (mode.VerticalBeamWidth * (Math.PI / 180.0));
var emitterCount = (int)(emitterSize / (dz * 2));
var emitterSpacing = 1.0;
var weights = new List<double> { 1 };
if (emitterCount > 1)
{
emitterSpacing = emitterSize / (emitterCount - 1);
// chebyshev window calculations for relative emitter strength across the array
var discreteFourierTransform = new MathNet.Numerics.IntegralTransforms.Algorithms.DiscreteFourierTransform();
var r0 = Math.Pow(10, mode.SideLobeAttenuation / 20.0);
var n = emitterCount - 1;
var a = Complex.Cosh((1.0 / n) * Acosh(r0));
var am = new Complex[n];
for (var m = 0; m < n; m++) am[m] = a * Complex.Cos(Math.PI * m / n);
var wm = new Complex[n];
var sign = 1;
for (var i = 0; i < n; i++)
{
if (am[i].Magnitude > 1) wm[i] = sign * Complex.Cosh(n * Acosh(am[i]));
else wm[i] = sign * Complex.Cos(n * Complex.Acos(am[i]));
sign *= -1;
}
discreteFourierTransform.BluesteinInverse(wm, FourierOptions.Default);
weights = wm.Select(e => e.Real).ToList();
weights[0] /= 2;
weights.Add(weights[0]);
var maxWeight = weights.Max();
for (var i = 0; i < weights.Count; i++) weights[i] /= maxWeight;
}
steerableArrayFile.WriteLine("{0}\t{1}\t{2}", emitterCount, emitterSpacing, mode.DepressionElevationAngle);
for (var i = 0; i < emitterCount; i++) steerableArrayFile.WriteLine("{0}", weights[i]);
}
//File.Copy(Path.Combine(AssemblyLocation, "sra.in"), Path.Combine(tempDirectory, "sra.in"));
//Debug.WriteLine(string.Format("Env File: {0} copied to: {1}", envFileName, tempDirectory));
// Now that we've got the files ready to go, we can launch bellhop to do the actual calculations
var ramProcess = new Process
{
StartInfo = new ProcessStartInfo(Path.Combine(AssemblyLocation, "RAMGeo.exe"))
{
CreateNoWindow = true,
UseShellExecute = false,
RedirectStandardInput = false,
RedirectStandardOutput = true,
RedirectStandardError = true,
WorkingDirectory = tempDirectory
}
};
if (radial.IsDeleted) throw new RadialDeletedByUserException();
ramProcess.Start();
try
{
ramProcess.PriorityClass = ProcessPriorityClass.Idle;
}
catch (InvalidOperationException) { }
//ramProcess.BeginOutputReadLine();
while (!ramProcess.HasExited)
{
if (radial.IsDeleted)
{
ramProcess.Kill();
throw new RadialDeletedByUserException();
}
Thread.Sleep(20);
}
var ramOutput = ramProcess.StandardOutput.ReadToEnd();
var ramError = ramProcess.StandardError.ReadToEnd();
if (ramProcess.ExitCode != 0)
{
Debug.WriteLine("RAMGeo process for radial {0} exited with error code {1:X}", radial.BasePath, ramProcess.ExitCode);
Debug.WriteLine(ramError);
Directory.Delete(tempDirectory, true);
return;
}
//File.Delete(Path.Combine(tempDirectory, "ramgeo.in"));
//File.Delete(radial.BasePath + ".grid");
//File.Move(Path.Combine(tempDirectory, "tl.grid"), radial.BasePath + ".grid");
//File.Delete(radial.BasePath + ".line");
//File.Move(Path.Combine(tempDirectory, "tl.line"), radial.BasePath + ".line");
//File.Delete(radial.BasePath + ".pgrid");
//File.Move(Path.Combine(tempDirectory, "p.grid"), radial.BasePath + ".pgrid");
//File.Delete(radial.BasePath + ".sra");
//File.Move(Path.Combine(tempDirectory, "sra.in"), radial.BasePath + ".sra");
using (var writer = new StreamWriter(radial.BasePath + ".bty")) writer.Write(bottomProfile.ToBellhopString());
if (File.Exists(Path.Combine(tempDirectory, "p.grid")))
{
var pressures = ReadPGrid(Path.Combine(tempDirectory, "p.grid"));
File.Copy(Path.Combine(tempDirectory, "p.grid"), radial.BasePath + ".pgrid", true);
//File.Delete(radial.BasePath + ".pgrid");
if (pressures.Count == 0)
{
Debug.WriteLine("Temp directory: " + tempDirectory);
Debug.WriteLine("RAMGeo stdout: " + ramOutput);
Debug.WriteLine("RAMGeo stderr: " + ramError);
Directory.Delete(tempDirectory, true);
return;
}
var rangeCount = pressures.Count;
var depthCount = pressures[0].Length;
var rr = new double[rangeCount];
var rd = new double[depthCount];
for (var rangeIndex = 0; rangeIndex < rr.Length; rangeIndex++) rr[rangeIndex] = (rangeIndex + 1) * dr * ndr;
for (var depthIndex = 0; depthIndex < rd.Length; depthIndex++) rd[depthIndex] = depthIndex * zstep;
//Debug.WriteLine("Scenario: '{0}' Mode: '{2}' Analysis point: {1} Bearing: {3}, zmplt: {4}, zstep: {5}, maxDepth: {6}, fileName: {7}, reqDepthCells: {8}, actualDepthCells: {9}",
// radial.TransmissionLoss.AnalysisPoint.Scenario.Name,
// radial.TransmissionLoss.AnalysisPoint.Geo,
// radial.TransmissionLoss.Modes[0].ModeName,
// radial.Bearing,
// zmplt,
// zstep,
// rd.Last(),
// Path.GetFileNameWithoutExtension(radial.BasePath),
// zmplt / zstep,
// depthCount);
var shadeFile = new ShadeFile(sourceDepth, frequency, rd, rr, pressures);
shadeFile.Write(radial.BasePath + ".shd");
//BellhopOutput.WriteShadeFile(radial.BasePath + ".shd", sourceDepth, frequency, rd, rr, pressures);
}
else
{
//Debug.WriteLine("Scenario: {0} Analysis point: {1} Mode {2} Bearing {3}",
// radial.TransmissionLoss.AnalysisPoint.Scenario.Name,
// radial.TransmissionLoss.AnalysisPoint.Geo,
// radial.TransmissionLoss.Modes[0].ModeName,
// radial.Bearing);
//Debug.WriteLine("p.grid file not found in RAMGeo output directory");
}
Directory.Delete(tempDirectory, true);
//Debug.WriteLine(string.Format("Env File: {0} temp directory deleted: {1}", envFileName, tempDirectory));
}
public static ShadeFile Read(string bellhopFilename, float bearingFromSource)
{
var shadeFile = new ShadeFile { BearingFromSource = bearingFromSource };
var retry = 20;
while (!File.Exists(bellhopFilename) && retry > 0)
{
Thread.Sleep(50);
retry--;
}
using (var reader = new BinaryReader(new FileStream(bellhopFilename, FileMode.Open, FileAccess.Read)))
{
var recordLength = reader.ReadInt32() * 4;
shadeFile.Title = new string(reader.ReadChars(80)).Trim();
reader.BaseStream.Seek(recordLength, SeekOrigin.Begin);
shadeFile.PlotType = new string(reader.ReadChars(10));
shadeFile.Xs = reader.ReadSingle();
shadeFile.Ys = reader.ReadSingle();
reader.BaseStream.Seek(2 * recordLength, SeekOrigin.Begin);
shadeFile.Frequency = reader.ReadSingle();
//Theta = new float[reader.ReadInt32()];
var thetaCount = reader.ReadInt32();
shadeFile.SourceDepths = new float[reader.ReadInt32()];
shadeFile.ReceiverDepths = new float[reader.ReadInt32()];
shadeFile.ReceiverRanges = new float[reader.ReadInt32()];
reader.BaseStream.Seek(3 * recordLength, SeekOrigin.Begin);
for (var curTheta = 0; curTheta < thetaCount; curTheta++) reader.ReadSingle();
reader.BaseStream.Seek(4 * recordLength, SeekOrigin.Begin);
for (var source = 0; source < shadeFile.SourceDepths.Length; source++) shadeFile.SourceDepths[source] = reader.ReadSingle();
reader.BaseStream.Seek(5 * recordLength, SeekOrigin.Begin);
for (var depth = 0; depth < shadeFile.ReceiverDepths.Length; depth++) shadeFile.ReceiverDepths[depth] = reader.ReadSingle();
reader.BaseStream.Seek(6 * recordLength, SeekOrigin.Begin);
int range;
for (range = 0; range < shadeFile.ReceiverRanges.Length; range++) shadeFile.ReceiverRanges[range] = reader.ReadSingle();
shadeFile._pressure = new Complex[shadeFile.ReceiverDepths.Length, shadeFile.ReceiverRanges.Length];
for (var curTheta = 0; curTheta < thetaCount; curTheta++)
{
for (var source = 0; source < shadeFile.SourceDepths.Length; source++)
{
for (var depth = 0; depth < shadeFile.ReceiverDepths.Length; depth++)
{
var recordNumber = 7 + (curTheta * shadeFile.SourceDepths.Length * shadeFile.ReceiverDepths.Length) + (source * shadeFile.ReceiverDepths.Length) + depth;
reader.BaseStream.Seek(recordNumber * recordLength, SeekOrigin.Begin);
for (range = 0; range < shadeFile.ReceiverRanges.Length; range++)
shadeFile._pressure[depth, range] = new Complex(reader.ReadSingle(), reader.ReadSingle());
} // for Depth
} // for Source
} // for CurTheta
} // using
shadeFile.DataMin = shadeFile.StatMin = float.MaxValue;
shadeFile.DataMax = shadeFile.StatMax = float.MinValue;
shadeFile.ExtractStatisticalData();
return shadeFile;
}
public void ReleaseAxisData()
{
_ranges = null;
_depths = null;
_bottomProfile = null;
_minimumTransmissionLossValues = null;
_maximumTransmissionLossValues = null;
_shadeFile = null;
}
public void Recalculate()
{
IsCalculated = false;
_bottomProfile = null;
_shadeFile = null;
_depths = _ranges = null;
_minimumTransmissionLossValues = _maximumTransmissionLossValues = _meanTransmissionLossValues = null;
var files = Directory.GetFiles(Path.GetDirectoryName(BasePath), Path.GetFileNameWithoutExtension(BasePath) + ".*");
foreach (var file in files) FileDeleteWithRetry(file);
Globals.TransmissionLossCalculatorService.Add(this);
}
public bool ExtractAxisData(int debugIndex = -1)
{
try
{
try
{
if (BasePath == null || File.Exists(BasePath + ".axs") || !File.Exists(BasePath + ".shd")) return false;
if (_shadeFile == null) _shadeFile = ShadeFile.Read(BasePath + ".shd", (float)Bearing);
if (_bottomDepths != null) _shadeFile.BottomDepths = _bottomDepths;
}
catch (EndOfStreamException)
{
FileDeleteWithRetry(BasePath + ".shd");
Globals.TransmissionLossCalculatorService.Add(this);
return false;
}
_ranges = _shadeFile.ReceiverRanges.ToArray();
_depths = _shadeFile.ReceiverDepths.ToArray();
IsCalculated = true;
_bottomProfile = ESME.TransmissionLoss.Bellhop.BottomProfile.FromBellhopFile(BasePath + ".bty");
_minimumTransmissionLossValues = new float[Ranges.Length];
_maximumTransmissionLossValues = new float[Ranges.Length];
_meanTransmissionLossValues = new float[Ranges.Length];
_bottomDepths = new float[Ranges.Length];
for (var rangeIndex = 0; rangeIndex < Ranges.Length; rangeIndex++)
{
//if (debugIndex >= 0 && rangeIndex == debugIndex) Debugger.Break();
// Updated to ignore values below the bottom
var curRange = _ranges[rangeIndex];
var depthAtThisRange = (from profilePoint in BottomProfile
let desiredRange = Math.Abs((profilePoint.Range * 1000) - curRange)
orderby desiredRange
select profilePoint.Depth).Take(2).Min();
_bottomDepths[rangeIndex] = (float)depthAtThisRange;
if (depthAtThisRange <= _depths[0])
{
MinimumTransmissionLossValues[rangeIndex] = float.NaN;
MaximumTransmissionLossValues[rangeIndex] = float.NaN;
MeanTransmissionLossValues[rangeIndex] = float.NaN;
continue;
}
var bottomDepthIndex = _depths.ToList().IndexOf((from depth in _depths
let curDepth = depthAtThisRange - depth
where curDepth > 0
orderby curDepth
select depth).First());
var tlValuesAboveBottom = _shadeFile[rangeIndex].Take(bottomDepthIndex).Where(v => !float.IsNaN(v) && !float.IsInfinity(v)).ToList();
if (tlValuesAboveBottom.Count == 0)
{
MinimumTransmissionLossValues[rangeIndex] = float.NaN;
MaximumTransmissionLossValues[rangeIndex] = float.NaN;
MeanTransmissionLossValues[rangeIndex] = float.NaN;
continue;
}
if (debugIndex >= 0 && rangeIndex == debugIndex)
{
var maxTransmissionLoss = tlValuesAboveBottom.Max();
var maxTransmissionLossDepthIndex = _shadeFile[rangeIndex].IndexOf(maxTransmissionLoss);
var maxTransmissionLossDepth = _depths[maxTransmissionLossDepthIndex];
Debug.WriteLine("Maximum TL value for this field found at radial bearing {0}, range {1}, depth {2}, TL {3}, bottom depth at this range {4}", Bearing, curRange, maxTransmissionLossDepth, maxTransmissionLoss, depthAtThisRange);
}
MinimumTransmissionLossValues[rangeIndex] = tlValuesAboveBottom.Min();
MaximumTransmissionLossValues[rangeIndex] = tlValuesAboveBottom.Max();
MeanTransmissionLossValues[rangeIndex] = tlValuesAboveBottom.Average();
}
_shadeFile.BottomDepths = _bottomDepths;
using (var writer = new BinaryWriter(new FileStream(BasePath + ".axs", FileMode.Create)))
{
writer.Write(_ranges.Length);
foreach (var range in _ranges) writer.Write(range);
writer.Write(_depths.Length);
foreach (var depth in _depths) writer.Write(depth);
writer.Write(_minimumTransmissionLossValues.Length);
foreach (var tl in _minimumTransmissionLossValues) writer.Write(tl);
writer.Write(_maximumTransmissionLossValues.Length);
foreach (var tl in _maximumTransmissionLossValues) writer.Write(tl);
writer.Write(_meanTransmissionLossValues.Length);
foreach (var tl in _meanTransmissionLossValues) writer.Write(tl);
writer.Write(_bottomDepths.Length);
foreach (var depth in _bottomDepths) writer.Write(depth);
}
//MediatorMessage.Send(MediatorMessage.TransmissionLossLayerChanged, TransmissionLoss);
return true;
}
catch (Exception)
{
if (IsDeleted) return false;
throw;
}
}