public static float BodyNoiseTemp(RealAntenna rx, CelestialBody body, Vector3d rxPointing) =>
BodyNoiseTemp(new double3(rx.PrecisePosition.x, rx.PrecisePosition.y, rx.PrecisePosition.z),
rx.Gain,
new double3(rxPointing.x, rxPointing.y, rxPointing.z),
new double3(body.position.x, body.position.y, body.position.z),
(float)body.Radius,
body.isStar ? StarRadioTemp(BodyBaseTemperature(body), rx.Frequency) : BodyBaseTemperature(body));
public static double BodyNoiseTemp(RealAntenna rx, CelestialBody body, Vector3d rxPointing)
{
if (rx.Shape == AntennaShape.Omni)
{
return(0); // No purpose in per-body noise temp for an omni.
}
Vector3 toBody = body.position - rx.Position;
double angle = Vector3.Angle(rxPointing, toBody);
// if (rx.GainAtAngle(Convert.ToSingle(angle)) < 0)
if (rx.Beamwidth < angle)
{
return(0); // Pointed too far away
}
double bw = rx.Beamwidth;
double t = body.GetTemperature(1); // TODO: Get the BLACKBODY temperature!
double d = body.Radius * 2;
double Rsqr = (rx.Position - body.position).sqrMagnitude;
double G = RATools.LinearScale(rx.Gain);
double angleRatio = angle / bw;
double result = (t * G * d * d / (16 * Rsqr)) * Math.Pow(Math.E, -2.77 * angleRatio * angleRatio);
// Debug.LogFormat("Planetary Body Noise Power Estimator: Body {0} base temp {1:F0} diameter {2:F0}km at {3:F2}Mm Gain {4:F1} vs HPBW {5:F1} incident angle {6:F1} yields {7:F1}K", body, t, d/1000, (rx.Position - body.position).magnitude/1e6, G, bw, angle, result);
return(result);
}
public RealAntennaDigital(RealAntenna orig) : base(orig)
{
if (orig is RealAntennaDigital o)
{
modulator = new RAModulator(o.modulator);
}
}
private static double AntennaMicrowaveTemp(RealAntenna rx)
{
if ((rx.ParentNode as RACommNode)?.ParentVessel is Vessel)
{
return(rx.TechLevelInfo.ReceiverNoiseTemperature);
}
return(rx.AMWTemp);
}
public static float AtmosphericTemp(RealAntenna rx, Vector3d origin)
{
if (rx.ParentNode is RACommNode rxNode && rxNode.ParentBody != null)
{
Vector3d normal = rxNode.GetSurfaceNormalVector();
return(AtmosphericTemp(new double3(rx.Position.x, rx.Position.y, rx.Position.z),
new double3(normal.x, normal.y, normal.z),
new double3(origin.x, origin.y, origin.z),
rx.Frequency));
}
return(0);
}
void GUIDisplay(int windowID)
{
string s = $"{(sourceAntenna?.ParentNode as RACommNode)?.ParentVessel?.vesselName} {sourceAntenna?.ToStringShort()}";
GUILayout.Label($"Antenna: {(sourceAntenna is RealAntenna ? s : "Not Selected")}");
GUILayout.BeginHorizontal();
GUILayout.BeginVertical();
if (GUILayout.Button($"Source Sort Mode: {sourceSortMode}"))
{
//(i1, i2) => i1.ToString().CompareTo(i2.ToString())
sourceSortMode = (SortMode)(((int)(sourceSortMode + 1)) % System.Enum.GetNames(typeof(SortMode)).Length);
SortList(sourceVessels, sourceSortMode);
}
scrollSourcePos = GUILayout.BeginScrollView(scrollSourcePos, GUILayout.ExpandWidth(true));
foreach (var ra in from Vessel v in sourceVessels
from RealAntenna ra in (v.Connection?.Comm as RACommNode)?.RAAntennaList?.Where(x => x.CanTarget)
select ra)
{
if (GUILayout.Button($"{(ra.ParentNode as RACommNode)?.ParentVessel?.vesselName} {ra.ToStringShort()}"))
{
sourceAntenna = ra;
}
}
GUILayout.EndScrollView();
GUILayout.EndVertical();
GUILayout.BeginVertical();
if (GUILayout.Button($"Target Sort Mode: {targetSortMode}"))
{
targetSortMode = (SortMode)(((int)(targetSortMode + 1)) % System.Enum.GetNames(typeof(SortMode)).Length);
SortList(targetVessels, targetSortMode);
}
scrollTargetPos = GUILayout.BeginScrollView(scrollTargetPos, GUILayout.ExpandWidth(true));
foreach (var v in targetVessels)
{
if (sourceAntenna is RealAntenna && GUILayout.Button($"{v.vesselName}"))
{
sourceAntenna.Target = v;
}
}
foreach (var v in FlightGlobals.Bodies)
{
if (sourceAntenna is RealAntenna && GUILayout.Button($"{v.name}"))
{
sourceAntenna.Target = v;
}
}
GUILayout.EndScrollView();
GUILayout.EndVertical();
GUILayout.EndHorizontal();
GUI.DragWindow();
}
private static double AtmosphericTemp(RealAntenna rx, Vector3d origin)
{
if (rx.ParentNode is RACommNode rxNode && rxNode.ParentBody != null)
{
Vector3d normal = rxNode.GetSurfaceNormalVector();
Vector3d to_origin = origin - rx.Position;
double angle = Vector3d.Angle(normal, to_origin);
double elevation = Math.Max(0, 90.0 - angle);
return(AtmosphereNoiseTemperature(elevation, rx.Frequency));
}
return(0);
}
private static float CosmicBackgroundTemp(RealAntenna rx, Vector3d origin)
{
float temp = 3;
if (rx.ParentNode is RACommNode rxNode)
{
Vector3d normal = (rxNode.ParentBody is CelestialBody) ? rxNode.GetSurfaceNormalVector() : Vector3d.zero;
Vector3d to_origin = origin - rx.Position;
temp = CosmicBackgroundTemp(new double3(normal.x, normal.y, normal.z),
new double3(to_origin.x, to_origin.y, to_origin.z),
rx.Frequency,
rxNode.isHome);
}
return(temp);
}
private static double CosmicBackgroundTemp(RealAntenna rx, Vector3d origin)
{
double CMB = 2.725;
double lossFactor = 1;
if (rx.ParentNode is RACommNode rxNode && rxNode.ParentBody != null)
{
float CD = 0.5f;
Vector3d normal = rxNode.GetSurfaceNormalVector();
Vector3d to_origin = origin - rx.Position;
double angle = Vector3d.Angle(normal, to_origin);
double elevation = Math.Max(0, 90.0 - angle);
lossFactor = RATools.LinearScale(AtmosphereAttenuation(CD, elevation, rx.Frequency));
}
return(CMB / lossFactor);
}
public static RealAntenna HighestGainCompatibleDSNAntenna(List <CommNode> nodes, RealAntenna peer)
{
RealAntenna result = null;
double highestGain = 0;
foreach (RACommNode node in nodes.Where(obj => obj.isHome))
{
foreach (RealAntenna ra in node.RAAntennaList)
{
if (peer.Compatible(ra) && ra.Gain > highestGain)
{
highestGain = ra.Gain;
result = ra;
}
}
}
return(result);
}
public static double AllBodyTemps(RealAntenna rx, Vector3d rxPointing)
{
double temp = 0;
if (rx.Shape != AntennaShape.Omni)
{
Profiler.BeginSample("RA Physics AllBodyTemps MainLoop");
RACommNode node = rx.ParentNode as RACommNode;
// Note there are ~33 bodies in RSS.
foreach (CelestialBody body in FlightGlobals.Bodies)
{
if (!node.isHome || !node.ParentBody.Equals(body))
{
temp += BodyNoiseTemp(rx, body, rxPointing);
}
}
Profiler.EndSample();
}
return(temp);
}
public static double NoiseTemperature(RealAntenna rx, Vector3d origin)
{
double amt = AntennaMicrowaveTemp(rx);
double atmos = AtmosphericTemp(rx, origin);
double cosmic = CosmicBackgroundTemp(rx, origin);
//double allbody = (rx.ParentNode.isHome) ? AllBodyTemps(rx, origin - rx.Position) : AllBodyTemps(rx, rx.ToTarget);
// Home Stations are directional, but treated as always pointing towards the peer.
double allbody = (rx.ParentNode.isHome) ? AllBodyTemps(rx, origin - rx.Position) : rx.cachedRemoteBodyNoiseTemp;
double total = amt + atmos + cosmic + allbody;
// Debug.LogFormat("NoiseTemp: Antenna {0:F2} Atmos: {1:F2} Cosmic: {2:F2} Bodies: {3:F2} Total: {4:F2}", amt, atmos, cosmic, allbody, total);
return(total);
//
// https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.372-7-200102-S!!PDF-E.pdf
//
// Sky Temperature: curves that vary based on atmosphere composition of a body.
// Earth example: http://www.delmarnorth.com/microwave/requirements/satellite_noise.pdf
// <10 deg K @ <15GHz and >30deg elevation in clear weather
// Rain can be a very large contributor, tho.
// At 0 deg elevation, sky temperature is effectively Earth ambient temperature = 290K.
// An omni antenna near Earth has a temperature = Earth ambient temperature = 290K.
// A directional antenna on a satellite pointed at Earth s.t. the entire main lobe of the ant
// is the Earth also has a noise temperature ~= 290K.
// A directional antenna pointed at the sun s.t. its main lobe encompasses ONLY the sun
// (so very directional) has an antenna temperature ~= 6000K?
// Ref: Galactic noise is high below 1000 MHz. At around 150 MHz, it is approximately 1000 K. At 2500 MHz, it has leveled off to around 10 K.
// Atmospheric absorption: Earth example: <1dB @ <20GHz
// Rainfall has a specific attenuation from absorption, and
// and a correlated contribution to sky temperature from re-emission.
// We should either track the effective temperature of the receiver electronics,
// or calculate it from its more conventional notation (to me) of noise figure.
// So we can get system temperature = antenna effective temperature + sky temperature + receiver effective temperature
// Sky we can "define" based on the near celestial body, or set as 3K for deep space.
// Receiver effective temperature we can derive from a noise figure.
// Antenna temperature is basically the notion of "sky" temperature + rain temperature, or 3-4K in deep space.
//
// P(dBW) = 10*log10(Kb*T*bandwidth) = -228.59917 + 10*log10(T*BW)
}
public static double ReceivedPower(RealAntenna tx, RealAntenna rx, double distance, double frequency = 1e9) => tx.TxPower + tx.Gain - PathLoss(distance, frequency) - PointingLoss(tx, rx.Position) - PointingLoss(rx, tx.Position) + rx.Gain;
private bool RenderPanel(SelectionMode mode, ref RealAntenna antenna, ref Vector2 scrollPos, in RealAntenna peer, GUIStyle buttonStyle)
private static double AntennaMicrowaveTemp(RealAntenna rx) => ((rx.ParentNode as RACommNode)?.ParentBody is CelestialBody) ? rx.AMWTemp : rx.TechLevelInfo.ReceiverNoiseTemperature;
public static double NoiseFloor(RealAntenna rx, double noiseTemp) => NoiseSpectralDensity(noiseTemp) + (10 * Math.Log10(rx.Bandwidth));
private bool RenderPanel(SelectionMode mode, ref RealAntenna antenna, ref Vector2 scrollPos)
{
bool res = false;
scrollPos = GUILayout.BeginScrollView(scrollPos);
if (mode == SelectionMode.Vessel)
{
if (HighLogic.LoadedSceneIsEditor)
{
foreach (var x in protoVesselAntennaCache)
{
foreach (RealAntenna ra in x.Value)
{
if (GUILayout.Button($"{x.Key.vesselName} {ra.ToStringShort()}"))
{
antenna = ra;
res = true;
}
}
}
ShipConstruct sc = EditorLogic.RootPart.ship;
foreach (Part p in sc.Parts)
{
foreach (ModuleRealAntenna mra in p.FindModulesImplementing <ModuleRealAntenna>())
{
if (GUILayout.Button($"{sc.shipName} {mra.RAAntenna.ToStringShort()}"))
{
antenna = mra.RAAntenna;
res = true;
}
}
}
}
foreach (Vessel v in FlightGlobals.Vessels.Where(x => x.Connection?.Comm is RACommNode))
{
foreach (RealAntenna ra in (v.Connection.Comm as RACommNode).RAAntennaList)
{
if (GUILayout.Button($"{v.GetDisplayName()} {ra.ToStringShort()}"))
{
antenna = ra;
res = true;
}
}
}
}
else
{
foreach (Network.RACommNetHome home in RACommNetScenario.GroundStations.Values.Where(x => x.Comm is RACommNode))
{
foreach (RealAntenna ra in home.Comm.RAAntennaList)
{
if (GUILayout.Button($"{home.nodeName} {ra.ToStringShort()}"))
{
antenna = ra;
res = true;
}
}
}
}
GUILayout.EndScrollView();
return(res);
}
public override double BestDataRateToPeer(RealAntenna rx)
{
double dataRate = (BestPeerModulator(rx, out double modRate, out double codeRate)) ? modRate * codeRate : 0;
return(dataRate);
}
public static double PointingLoss(RealAntenna ant, Vector3 origin) => (ant.CanTarget && ant.ToTarget != Vector3.zero) ? PointingLoss(Vector3.Angle(origin - ant.Position, ant.ToTarget), ant.Beamwidth) : 0;
public static float ReceivedPower(RealAntenna tx, RealAntenna rx, float distance, float frequency = 1e9f) => tx.TxPower + tx.Gain - PathLoss(distance, frequency) - PointingLoss(tx, rx.Position) - PointingLoss(rx, tx.Position) + rx.Gain;
public static double BodyNoiseTemp(RealAntenna rx, CelestialBody body, Vector3d rxPointing)
{
if (rx.Shape == AntennaShape.Omni)
{
return(0); // No purpose in per-body noise temp for an omni.
}
Vector3 toBody = body.position - rx.Position;
double angle = Vector3.Angle(rxPointing, toBody);
double distance = toBody.magnitude;
double bodyRadiusAngularRad = (distance > 10 * body.Radius)
? Math.Atan2(body.Radius, distance)
: MathUtils.AngularRadius(body.Radius, distance) * Mathf.Deg2Rad;
double bodyRadiusAngularDeg = bodyRadiusAngularRad * Mathf.Rad2Deg;
if (rx.Beamwidth < angle - bodyRadiusAngularDeg)
{
return(0); // Pointed too far away
}
double baseTemp = body.atmosphere ? body.GetTemperature(1) : GetEquilibriumTemperature(body) + body.coreTemperatureOffset;
double t = body.isStar ? StarRadioTemp(baseTemp, rx.Frequency) : baseTemp; // TODO: Get the BLACKBODY temperature!
if (t < double.Epsilon)
{
return(0);
}
double angleRad = angle * Mathf.Deg2Rad;
double beamwidthRad = rx.Beamwidth * Mathf.Deg2Rad;
double gainDelta; // Antenna Pointing adjustment
double viewedAreaBase;
// How much of the body is in view of the antenna?
if (rx.Beamwidth < bodyRadiusAngularDeg - angle) // Antenna viewable area completely enclosed by body
{
viewedAreaBase = Mathf.PI * beamwidthRad * beamwidthRad;
gainDelta = 0;
}
else if (rx.Beamwidth > bodyRadiusAngularDeg + angle) // Antenna viewable area completely encloses body
{
viewedAreaBase = Mathf.PI * bodyRadiusAngularRad * bodyRadiusAngularRad;
gainDelta = rx.GainAtAngle(angle) - rx.Gain;
}
else
{
viewedAreaBase = MathUtils.CircleCircleIntersectionArea(beamwidthRad, bodyRadiusAngularRad, angleRad);
double intersectionCenter = MathUtils.CircleCircleIntersectionOffset(beamwidthRad, bodyRadiusAngularRad, angleRad);
gainDelta = rx.GainAtAngle((intersectionCenter + beamwidthRad) * Mathf.Rad2Deg / 2) - rx.Gain;
}
// How much of the antenna viewable area is occupied by the body
double antennaViewableArea = Mathf.PI * beamwidthRad * beamwidthRad;
double viewableAreaRatio = viewedAreaBase / antennaViewableArea;
/*
* double d = body.Radius * 2;
* double Rsqr = toBody.sqrMagnitude;
* double G = RATools.LinearScale(rx.Gain);
* double angleRatio = angle / rx.Beamwidth;
*
* // https://deepspace.jpl.nasa.gov/dsndocs/810-005/Binder/810-005_Binder_Change51.pdf Module 105: 2.4.3 Planetary Noise estimator
* // This estimator is correct for the DSN viewing planets, but wrong for the sun & moon.
* double result = (t * G * d * d / (16 * Rsqr)) * Math.Pow(Math.E, -2.77 * angleRatio * angleRatio);
*/
double result = t * viewableAreaRatio * RATools.LinearScale(gainDelta);
//Debug.Log($"Planetary Body Noise Power Estimator: Body {body} Temp: {t:F0} AngularDiameter: {bodyRadiusAngularDeg * 2:F1} @ {angle:F1} HPBW: {rx.Beamwidth:F1} ViewableAreaRatio: {viewableAreaRatio:F2} gainDelta: {gainDelta:F4} result: {result}");
return(result);
}
private bool BestPeerModulator(RealAntenna rx, out double modRate, out double codeRate)
{
RealAntennaDigital tx = this;
Antenna.Encoder encoder = Antenna.Encoder.BestMatching(tx.Encoder, rx.Encoder);
codeRate = encoder.CodingRate;
modRate = 0;
if (!(rx is RealAntennaDigital))
{
return(false);
}
if (!Compatible(rx))
{
return(false);
}
if ((tx.Parent is ModuleRealAntenna) && !tx.Parent.CanComm())
{
return(false);
}
if ((rx.Parent is ModuleRealAntenna) && !rx.Parent.CanComm())
{
return(false);
}
Vector3 toSource = rx.Position - tx.Position;
double distance = toSource.magnitude;
RAModulator txMod = tx.modulator, rxMod = (rx as RealAntennaDigital).modulator;
if ((distance < tx.MinimumDistance) || (distance < rx.MinimumDistance))
{
return(false);
}
if (!txMod.Compatible(rxMod))
{
return(false);
}
int maxBits = Math.Min(txMod.ModulationBits, rxMod.ModulationBits);
double maxSymbolRate = Math.Min(txMod.SymbolRate, rxMod.SymbolRate);
double minSymbolRate = Math.Max(txMod.MinSymbolRate, rxMod.MinSymbolRate);
double RxPower = Physics.ReceivedPower(tx, rx, distance, tx.Frequency);
double temp = Physics.NoiseTemperature(rx, tx.Position);
double N0 = Physics.NoiseSpectralDensity(temp); // In dBm
double minEb = encoder.RequiredEbN0 + N0; // in dBm
double maxBitRateLog = RxPower - minEb; // in dB*Hz
double maxBitRate = RATools.LinearScale(maxBitRateLog);
/*
* Vessel tv = (tx.ParentNode as RACommNode).ParentVessel;
* Vessel rv = (rx.ParentNode as RACommNode).ParentVessel;
* if (tv != null && rv != null)
* {
* string debugStr = $"{ModTag} {tx} to {rx} RxP {RxPower:F2} vs temp {temp:F2}. NSD {N0:F1}, ReqEb/N0 {encoder.RequiredEbN0:F1} -> minEb {minEb:F1} gives maxRate {RATools.PrettyPrint(maxBitRate)}bps vs symbol rates {RATools.PrettyPrint(minSymbolRate)}Sps-{RATools.PrettyPrint(maxSymbolRate)}Sps";
* Debug.Log(debugStr);
* }
*/
// We cannot slow our modulation enough to achieve the required Eb/N0, so fail.
if (maxBitRate < minSymbolRate)
{
return(false);
}
double targetRate;
int negotiatedBits;
if (maxBitRate <= maxSymbolRate)
{
// The required Eb/N0 occurs at a lower symbol rate than we are capable of at 1 bit/sec/Hz.
// Step down the symbol rate and modulate at 1 bit/sec/Hz (BPSK).
// (What if the modulator only supports schemes with >1 bits/symbol?)
// (Then our minimum EbN0 is an underestimate.)
float ratio = Convert.ToSingle(maxBitRate / maxSymbolRate);
double log2 = Math.Floor(Mathf.Log(ratio, 2));
targetRate = maxSymbolRate * Math.Pow(2, log2);
negotiatedBits = 1;
//debugStr += $" Selected rate {RATools.PrettyPrint(targetRate)}bps (MaxSymbolRate * log2 {log2})";
}
else
{
// We need to go to SNR here and rely a bit more on Shannon-Hartley
double Noise = N0 + RATools.LogScale(maxSymbolRate);
double CI = RxPower - Noise;
double margin = CI - encoder.RequiredEbN0;
targetRate = maxSymbolRate;
negotiatedBits = Math.Min(maxBits, Convert.ToInt32(1 + Math.Floor(margin / 3)));
//debugStr += $" Noise {Noise:F2} CI {CI:F2} margin {margin:F1}";
}
modRate = targetRate * negotiatedBits;
//Debug.LogFormat(debugStr);
return(true);
// Energy/bit (Eb) = Received Power / datarate
// N0 = Noise Spectral Density = K*T
// Noise = N0 * BW
// SNR = RxPower / Noise = RxPower / (N0 * BW) = Eb*datarate / N0*BW = (Eb/N0) * (datarate/BW)
// I < B * log(1 + S/N) where I = information rate, B=Bandwidth, S=Total Power, N=Total Noise Power = N0*B
//
// Es/N0 = (Total Power / Symbol Rate) / N0
// = Eb/N0 * log(modulation order)
}
private static double AntennaMicrowaveTemp(RealAntenna rx) => rx.AMWTemp;