示例#1
0
void NadirPointing::ComputeCosineMatrixAndAngularVelocity(Real atTime)
{
   //#ifdef DEBUG_NADIRPOINTING
   //#endif

   #ifdef DEBUG_NADIR_POINTING_COMPUTE
      MessageInterface::ShowMessage("In NadirPointing, computing at time %le\n",
            atTime);
      MessageInterface::ShowMessage("ModeOfConstraint = %s\n", modeOfConstraint.c_str());
      if (!owningSC) MessageInterface::ShowMessage("--- owningSC is NULL!!!!\n");
      if (!refBody) MessageInterface::ShowMessage("--- refBody is NULL!!!!\n");
   #endif

   if (!isInitialized || needsReinit)
   {
      Initialize();
      // Check for unset reference body pointer
      if (!refBody)
      {
         std::string attEx  = "Reference body ";
         attEx             += refBodyName + " not defined for attitude of type \"";
         attEx             += "NadirPointing\"";
         throw AttitudeException(attEx);
      }
   }

   /// using a spacecraft object, *owningSC
   A1Mjd theTime(atTime);

   Rvector6 scState = ((SpaceObject*) owningSC)->GetMJ2000State(theTime);
   Rvector6 refState = refBody->GetMJ2000State(theTime);
    
   Rvector3 pos(scState[0] - refState[0], scState[1] - refState[1],  scState[2] - refState[2]);
   Rvector3 vel(scState[3] - refState[3], scState[4] - refState[4],  scState[5] - refState[5]);

   #ifdef DEBUG_NADIR_POINTING_COMPUTE
      MessageInterface::ShowMessage("   scState  = %s\n", scState.ToString().c_str());
      MessageInterface::ShowMessage("   refState = %s\n", refState.ToString().c_str());
      MessageInterface::ShowMessage("   pos      = %s\n", pos.ToString().c_str());
      MessageInterface::ShowMessage("   vel      = %s\n", vel.ToString().c_str());
   #endif

   // Error message
   if ( bodyAlignmentVector.GetMagnitude() < 1.0e-5 )
   {
	   throw AttitudeException("The size of BodyAlignmentVector is too small.");
   }
   else if ( bodyConstraintVector.GetMagnitude() < 1.0e-5 )
   {
	   throw AttitudeException("The size of BodyConstraintVector is too small.");
   }
   else if ( bodyAlignmentVector.GetUnitVector()*bodyConstraintVector.GetUnitVector() > ( 1.0 - 1.0e-5) )
   {
	   throw AttitudeException("BodyAlignmentVector and BodyConstraintVector are the same.");
   }
   else if ( pos.GetMagnitude() < 1.0e-5 )
   {
	   throw AttitudeException("A position vector is zero.");
   }
   else if ( vel.GetMagnitude() < 1.0e-5 )
   {
	   throw AttitudeException("A velocity vector is zero.");
   }
   else if ( Cross(pos,vel).GetMagnitude() < 1.0e-5 )
   {
	   throw AttitudeException("Cross product of position and velocity is zero: LVLH frame cannot be defined.");
   }
   
   Rvector3 normal = Cross(pos,vel);

   Rvector3 xhat = pos/pos.GetMagnitude();
   Rvector3 yhat = normal/normal.GetMagnitude();
   Rvector3 zhat = Cross(xhat,yhat);

   #ifdef DEBUG_NADIR_POINTING_COMPUTE
      MessageInterface::ShowMessage("   normal  = %s\n", normal.ToString().c_str());
      MessageInterface::ShowMessage("   xhat    = %s\n", xhat.ToString().c_str());
      MessageInterface::ShowMessage("   yhat    = %s\n", yhat.ToString().c_str());
      MessageInterface::ShowMessage("   zhat    = %s\n", zhat.ToString().c_str());
   #endif

   // RiI calculation (from inertial to LVLH)
   Rmatrix33 RIi;
   RIi(0,0) = xhat(0);
   RIi(1,0) = xhat(1);
   RIi(2,0) = xhat(2);
   RIi(0,1) = yhat(0);
   RIi(1,1) = yhat(1);
   RIi(2,1) = yhat(2);
   RIi(0,2) = zhat(0);
   RIi(1,2) = zhat(1);
   RIi(2,2) = zhat(2);
   
   // Set alignment/constraint vector in body frame
   if ( modeOfConstraint == "OrbitNormal" )
   {
	   referenceVector[0] = -1;
	   referenceVector[1] = 0;
	   referenceVector[2] = 0;

	   constraintVector[0] = 0;
	   constraintVector[1] = 1;
	   constraintVector[2] = 0;
   }
   else if ( modeOfConstraint == "VelocityConstraint" )
   {
	   referenceVector[0] = -1;
	   referenceVector[1] = 0;
	   referenceVector[2] = 0;

	   constraintVector[0] = 0;
	   constraintVector[1] = 0;
	   constraintVector[2] = 1;
   }

   // RBi calculation using TRIAD (from LVLH to body frame)
   Rmatrix33 RiB = TRIAD( bodyAlignmentVector, bodyConstraintVector, referenceVector, constraintVector );

   // the rotation matrix (from body to inertial)
   dcm = RIi*RiB;
   // the final rotation matrix (from inertial to body)
   dcm =  dcm.Transpose();

   // We do NOT calculate angular velocity for Nadir.
   // TODO : Throw AttitudeException??
   /*
   Rmatrix33 wxIBB = - RBi*RiIDot*dcm.Transpose();
   Rvector3 wIBB;
   wIBB.Set(wxIBB(2,1),wxIBB(0,2),wxIBB(1,0));
   */
}
示例#2
0
//------------------------------------------------------------------------------
bool TDRSSTwoWayRange::Evaluate(bool withEvents)
{
   bool retval = false;

   if (!initialized)
      InitializeMeasurement();

   #ifdef DEBUG_RANGE_CALC
      MessageInterface::ShowMessage("Entered TDRSSTwoWayRange::Evaluate()\n");
      MessageInterface::ShowMessage("  ParticipantCount: %d\n",
            participants.size());
   #endif

   if (withEvents == false)
   {
      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("TDRSS 2-Way Range Calculation without "
               "events\n");
      #endif

      #ifdef VIEW_PARTICIPANT_STATES
         DumpParticipantStates("++++++++++++++++++++++++++++++++++++++++++++\n"
               "Evaluating TDRSS 2-Way Range without events");
      #endif

      if (CheckLOS(0, 1, NULL) && CheckLOS(1, 2, NULL))
      {
         // Calculate the range vector between the groundstation and the TDRS
         CalculateRangeVectorInertial(0, 1);
         Rvector3 outState;

         // Set feasibility off of topospheric horizon, set by the Z value in topo
         // coords
         std::string updateAll = "All";
         UpdateRotationMatrix(currentMeasurement.epoch, updateAll);
         outState = R_o_j2k * rangeVecInertial;
         currentMeasurement.feasibilityValue = outState[2];

         #ifdef CHECK_PARTICIPANT_LOCATIONS
            MessageInterface::ShowMessage("Evaluating without events\n");
            MessageInterface::ShowMessage("Calculating TDRSS 2-Way Range at epoch "
                  "%.12lf\n", currentMeasurement.epoch);
            MessageInterface::ShowMessage("   J2K Location of %s, id = '%s':  %s",
                  participants[0]->GetName().c_str(),
                  currentMeasurement.participantIDs[0].c_str(),
                  p1Loc.ToString().c_str());
            MessageInterface::ShowMessage("   J2K Location of %s, id = '%s':  %s",
                  participants[1]->GetName().c_str(),
                  currentMeasurement.participantIDs[1].c_str(),
                  p2Loc.ToString().c_str());
            Rvector3 bfLoc = R_o_j2k * p1Loc;
            MessageInterface::ShowMessage("   BodyFixed Location of %s:  %s",
                  participants[0]->GetName().c_str(),
                  bfLoc.ToString().c_str());
            bfLoc = R_o_j2k * p2Loc;
            MessageInterface::ShowMessage("   BodyFixed Location of %s:  %s\n",
                  participants[1]->GetName().c_str(),
                  bfLoc.ToString().c_str());
         #endif

         if (currentMeasurement.feasibilityValue > 0.0)
         {
            currentMeasurement.isFeasible = true;
            currentMeasurement.value[0] = rangeVecInertial.GetMagnitude();
            currentMeasurement.eventCount = 4;

            retval = true;
         }
      }
      else
      {
         currentMeasurement.isFeasible = false;
         currentMeasurement.value[0] = 0.0;
         currentMeasurement.eventCount = 0;
      }

      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("Calculating Range at epoch %.12lf\n",
               currentMeasurement.epoch);
         MessageInterface::ShowMessage("   Location of %s, id = '%s':  %s",
               participants[0]->GetName().c_str(),
               currentMeasurement.participantIDs[0].c_str(),
               p1Loc.ToString().c_str());
         MessageInterface::ShowMessage("   Location of %s, id = '%s':  %s",
               participants[1]->GetName().c_str(),
               currentMeasurement.participantIDs[1].c_str(),
               p2Loc.ToString().c_str());
         MessageInterface::ShowMessage("   Range Vector (inertial):  %s\n",
               rangeVecInertial.ToString().c_str());
         MessageInterface::ShowMessage("   R(Groundstation) dot RangeVec =  %lf\n",
               currentMeasurement.feasibilityValue);
         MessageInterface::ShowMessage("   Feasibility:  %s\n",
               (currentMeasurement.isFeasible ? "true" : "false"));
         MessageInterface::ShowMessage("   Range is %.12lf\n",
               currentMeasurement.value[0]);
         MessageInterface::ShowMessage("   EventCount is %d\n",
               currentMeasurement.eventCount);
      #endif

      #ifdef SHOW_RANGE_CALC
         MessageInterface::ShowMessage("Range at epoch %.12lf is ",
               currentMeasurement.epoch);
         if (currentMeasurement.isFeasible)
            MessageInterface::ShowMessage("feasible, value = %.12lf\n",
               currentMeasurement.value[0]);
         else
            MessageInterface::ShowMessage("not feasible\n");
      #endif
   }
   else
   {
      // Calculate the corrected range measurement
      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("TDRSS 2-Way Range Calculation:\n");
      #endif

      #ifdef VIEW_PARTICIPANT_STATES
         DumpParticipantStates("********************************************\n"
               "Evaluating TDRSS 2-Way Range with located events");
         MessageInterface::ShowMessage("Calculating TDRSS 2-Way Range at epoch "
               "%.12lf\n", currentMeasurement.epoch);
      #endif

      // Get the range from the downlink
      Rvector3 r1, r2;
      r1 = downlinkLeg.GetPosition(participants[0]);
      r2 = downlinkLeg.GetPosition(participants[1]);
      Rvector3 rVector = r2 - r1;
      Real realRange = rVector.GetMagnitude();

      #ifdef VIEW_PARTICIPANT_STATES
         MessageInterface::ShowMessage("   %s at downlink: %.12lf %.12lf %.12lf\n",
               participants[0]->GetName().c_str(), r1[0], r1[1], r1[2]);
         MessageInterface::ShowMessage("   %s at downlink: %.12lf %.12lf %.12lf\n",
               participants[1]->GetName().c_str(), r2[0], r2[1], r2[2]);
      #endif
      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("   Downlink Range:  %.12lf\n",
               rVector.GetMagnitude());
      #endif

      r1 = backlinkLeg.GetPosition(participants[1]);
      r2 = backlinkLeg.GetPosition(participants[2]);
      if (CheckSat2SatLOS(r1, r2, NULL) == false)
         return false;
      rVector = r2 - r1;
      realRange += rVector.GetMagnitude();
      #ifdef VIEW_PARTICIPANT_STATES
         MessageInterface::ShowMessage("   %s at backlink: %.12lf %.12lf %.12lf\n",
               participants[1]->GetName().c_str(), r1[0], r1[1], r1[2]);
         MessageInterface::ShowMessage("   %s at backlink: %.12lf %.12lf %.12lf\n",
               participants[2]->GetName().c_str(), r2[0], r2[1], r2[2]);
      #endif

      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("   Backlink Range:  %.12lf\n",
                  rVector.GetMagnitude());
      #endif

      // Add the pseudorange from the transponder delay
      targetDelay = GetDelay(2,0);
      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("   TDRSS target delay is %.12lf\n",
               targetDelay);
      #endif
      realRange += GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM / GmatMathConstants::KM_TO_M *
            targetDelay;

      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("   Delay Range (%le sec delay):  "
               "%.12lf\n", targetDelay,
               (GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM/GmatMathConstants::KM_TO_M * targetDelay));
      #endif

      r1 = forwardlinkLeg.GetPosition(participants[2]);
      r2 = forwardlinkLeg.GetPosition(participants[1]);
      if (CheckSat2SatLOS(r1, r2, NULL) == false)
         return false;
      rVector = r2 - r1;
      realRange += rVector.GetMagnitude();

      #ifdef VIEW_PARTICIPANT_STATES
         MessageInterface::ShowMessage("   %s at frwdlink: %.12lf %.12lf %.12lf\n",
               participants[2]->GetName().c_str(), r1[0], r1[1], r1[2]);
         MessageInterface::ShowMessage("   %s at frwdlink: %.12lf %.12lf %.12lf\n",
               participants[1]->GetName().c_str(), r2[0], r2[1], r2[2]);
      #endif
      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("   forwardlink Range:  %.12lf\n",
               rVector.GetMagnitude());
      #endif

      r1 = uplinkLeg.GetPosition(participants[1]);
      r2 = uplinkLeg.GetPosition(participants[0]);
      rVector = r2 - r1;
      realRange += rVector.GetMagnitude();

      #ifdef VIEW_PARTICIPANT_STATES
         MessageInterface::ShowMessage("   %s at frwdlink: %.12lf %.12lf %.12lf\n",
               participants[1]->GetName().c_str(), r1[0], r1[1], r1[2]);
         MessageInterface::ShowMessage("   %s at frwdlink: %.12lf %.12lf %.12lf\n",
               participants[0]->GetName().c_str(), r2[0], r2[1], r2[2]);
      #endif
      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("   Uplink Range:  %.12lf\n",
               rVector.GetMagnitude());
      #endif

      currentMeasurement.value[0] = realRange / 2.0;

      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("   Calculated Range:  %.12lf\n",
               currentMeasurement.value[0]);
      #endif

      retval = true;
   }

   return retval;
}
示例#3
0
//------------------------------------------------------------------------------
bool USNTwoWayRange::Evaluate(bool withEvents)
{
   bool retval = false;

   if (!initialized)
      InitializeMeasurement();

   #ifdef DEBUG_RANGE_CALC
      MessageInterface::ShowMessage("Entered USNTwoWayRange::Evaluate()\n");
      MessageInterface::ShowMessage("  ParticipantCount: %d\n",
            participants.size());
   #endif

   if (withEvents == false)
   {
      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("USN 2-Way Range Calculation without "
               "events\n");
      #endif

      #ifdef VIEW_PARTICIPANT_STATES
         DumpParticipantStates("++++++++++++++++++++++++++++++++++++++++++++\n"
               "Evaluating USN 2-Way Range without events");
      #endif

      CalculateRangeVectorInertial();
      Rvector3 outState;

      // Set feasibility off of topocentric horizon, set by the Z value in topo
      // coords
      std::string updateAll = "All";
      UpdateRotationMatrix(currentMeasurement.epoch, updateAll);
      outState = R_o_j2k * rangeVecInertial;
      currentMeasurement.feasibilityValue = outState[2];

      #ifdef CHECK_PARTICIPANT_LOCATIONS
         MessageInterface::ShowMessage("Evaluating without events\n");
         MessageInterface::ShowMessage("Calculating USN 2-Way Range at epoch "
               "%.12lf\n", currentMeasurement.epoch);
         MessageInterface::ShowMessage("   J2K Location of %s, id = '%s':  %s",
               participants[0]->GetName().c_str(),
               currentMeasurement.participantIDs[0].c_str(),
               p1Loc.ToString().c_str());
         MessageInterface::ShowMessage("   J2K Location of %s, id = '%s':  %s",
               participants[1]->GetName().c_str(),
               currentMeasurement.participantIDs[1].c_str(),
               p2Loc.ToString().c_str());
         Rvector3 bfLoc = R_o_j2k * p1Loc;
         MessageInterface::ShowMessage("   BodyFixed Location of %s:  %s",
               participants[0]->GetName().c_str(),
               bfLoc.ToString().c_str());
         bfLoc = R_o_j2k * p2Loc;
         MessageInterface::ShowMessage("   BodyFixed Location of %s:  %s\n",
               participants[1]->GetName().c_str(),
               bfLoc.ToString().c_str());
      #endif

      if (currentMeasurement.feasibilityValue > 0.0)
      {
         currentMeasurement.isFeasible = true;
         currentMeasurement.value[0] = rangeVecInertial.GetMagnitude();
         currentMeasurement.eventCount = 2;

         retval = true;
      }
      else
      {
         currentMeasurement.isFeasible = false;
         currentMeasurement.value[0] = 0.0;
         currentMeasurement.eventCount = 0;
      }

      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("Calculating Range at epoch %.12lf\n",
               currentMeasurement.epoch);
         MessageInterface::ShowMessage("   Location of %s, id = '%s':  %s",
               participants[0]->GetName().c_str(),
               currentMeasurement.participantIDs[0].c_str(),
               p1Loc.ToString().c_str());
         MessageInterface::ShowMessage("   Location of %s, id = '%s':  %s",
               participants[1]->GetName().c_str(),
               currentMeasurement.participantIDs[1].c_str(),
               p2Loc.ToString().c_str());
         MessageInterface::ShowMessage("   Range Vector:  %s\n",
               rangeVecInertial.ToString().c_str());
         MessageInterface::ShowMessage("   R(Groundstation) dot RangeVec =  %lf\n",
               currentMeasurement.feasibilityValue);
         MessageInterface::ShowMessage("   Feasibility:  %s\n",
               (currentMeasurement.isFeasible ? "true" : "false"));
         MessageInterface::ShowMessage("   Range is %.12lf\n",
               currentMeasurement.value[0]);
         MessageInterface::ShowMessage("   EventCount is %d\n",
               currentMeasurement.eventCount);
      #endif

      #ifdef SHOW_RANGE_CALC
         MessageInterface::ShowMessage("Range at epoch %.12lf is ",
               currentMeasurement.epoch);
         if (currentMeasurement.isFeasible)
            MessageInterface::ShowMessage("feasible, value = %.12lf\n",
               currentMeasurement.value[0]);
         else
            MessageInterface::ShowMessage("not feasible\n");
      #endif
   }
   else
   {
      // Calculate the corrected range measurement
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("USN 2-Way Range Calculation:\n");
      #endif

      #ifdef VIEW_PARTICIPANT_STATES_WITH_EVENTS
         DumpParticipantStates("********************************************\n"
               "Evaluating USN 2-Way Range with located events");
      #endif

      // 1. Get the range from the down link
      Rvector3 r1, r2;
      r1 = downlinkLeg.GetPosition(participants[0]);
      r2 = downlinkLeg.GetPosition(participants[1]);
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("r1 = (%f,  %f,  %f)\n", r1.Get(0), r1.Get(1), r1.Get(2));
         MessageInterface::ShowMessage("r2 = (%f,  %f,  %f)\n", r2.Get(0), r2.Get(1), r2.Get(2));
      #endif
      Rvector3 downlinkVector = r2 - r1;		// rVector = r2 - r1;
      downlinkRange = downlinkVector.GetMagnitude();
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Downlink Range = r2-r1:  %.12lf km\n",
               downlinkRange);
      #endif

	   // 2. Calculate down link range rate:
      Rvector3 p1V = downlinkLeg.GetVelocity(participants[0]);
      Rvector3 p2V = downlinkLeg.GetVelocity(participants[1]);
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("p1V = (%f,  %f,  %f)\n", p1V.Get(0), p1V.Get(1), p1V.Get(2));
         MessageInterface::ShowMessage("p2V = (%f,  %f,  %f)\n", p2V.Get(0), p2V.Get(1), p2V.Get(2));
      #endif
      // @todo Relative origin velocities need to be subtracted when the origins
      // differ; check and fix that part using r12_j2k_vel here.  It's not yet
      // incorporated because we need to handle the different epochs for the
      // bodies, and we ought to do this part in barycentric coordinates
      Rvector downRRateVec = p2V - p1V /* - r12_j2k_vel*/;
      Rvector3 rangeUnit = downlinkVector.GetUnitVector();
      downlinkRangeRate = downRRateVec * rangeUnit;
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Downlink Range Rate:  %.12lf km/s\n",
               downlinkRangeRate);
      #endif

      // 3. Get the transponder delay
      targetDelay = GetDelay(1,0);
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage(
               "    USN Transponder delay for %s = %.12lf s\n",
               participants[1]->GetName().c_str(), targetDelay);
      #endif

      // 4. Get the range from the uplink
      Rvector3 r3, r4;
      r3 = uplinkLeg.GetPosition(participants[0]);
      r4 = uplinkLeg.GetPosition(participants[1]);
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("r3 = (%f,  %f,  %f)\n", r3.Get(0), r3.Get(1), r3.Get(2));
         MessageInterface::ShowMessage("r4 = (%f,  %f,  %f)\n", r4.Get(0), r4.Get(1), r4.Get(2));
      #endif
      Rvector3 uplinkVector = r4 - r3;
      uplinkRange = uplinkVector.GetMagnitude();
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Uplink Range = r4-r3:  %.12lf km\n",
               uplinkRange);
      #endif

	   // 5. Calculate up link range rate
      Rvector3 p3V = uplinkLeg.GetVelocity(participants[0]);
      Rvector3 p4V = uplinkLeg.GetVelocity(participants[1]);
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("p3V = (%f,  %f,  %f)\n", p3V.Get(0), p3V.Get(1), p3V.Get(2));
         MessageInterface::ShowMessage("p4V = (%f,  %f,  %f)\n", p4V.Get(0), p4V.Get(1), p4V.Get(2));
      #endif
      // @todo Relative origin velocities need to be subtracted when the origins
      // differ; check and fix that part using r12_j2k_vel here.  It's not yet
      // incorporated because we need to handle the different epochs for the
      // bodies, and we ought to do this part in barycentric coordinates
      Rvector upRRateVec = p4V - p3V /* - r12_j2k_vel*/ ;
      rangeUnit = uplinkVector.GetUnitVector();
      uplinkRangeRate = upRRateVec * rangeUnit;
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Uplink Range Rate:  %.12lf km/s\n",
               uplinkRangeRate);
      #endif

      // 5.1. Target range rate: Do we need this as well?
      targetRangeRate = (downlinkRangeRate + uplinkRangeRate) / 2.0;
	   #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Target Range Rate:  %.12lf km/s\n",
                targetRangeRate);
		#endif
      

	   // 6. Get sensors used in USN 2-ways range
	   ObjectArray objList1;
	   ObjectArray objList2;
	   ObjectArray objList3;
	   //			objList1 := all transmitters in participantHardware list
	   //			objList2 := all receivers in participantHardware list
	   //			objList3 := all transponders in participantHardware list
	   if (participantHardware.empty()||
	   		((!participantHardware.empty())&&
	   		  participantHardware[0].empty()&&
	   		  participantHardware[1].empty()
	   		)
	   	)
	   {
	   	// DO NOT LEAVE THIS TYPE OF MESSAGE IN THE CODE WITHOUT #ifdef WRAPPERS!!!
         //MessageInterface::ShowMessage("    Ideal measurement (no hardware delay and no media correction involve):\n");
		   Real realRange = (uplinkRange + downlinkRange)/2;
		   #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
				MessageInterface::ShowMessage("   Range = %.12lf km\n", realRange);
			#endif

	   	// Set value for currentMeasurement
		   currentMeasurement.value[0] = realRange;
	      currentMeasurement.isFeasible = true;

	      return true;
	   }

	   for(std::vector<Hardware*>::iterator hw = this->participantHardware[0].begin();
	   		hw != this->participantHardware[0].end(); ++hw)
	   {
	   	if ((*hw) != NULL)
	   	{
	   		if ((*hw)->GetTypeName() == "Transmitter")
	   			objList1.push_back(*hw);
	   		if ((*hw)->GetTypeName() == "Receiver")
	   			objList2.push_back(*hw);
	   	}
	   	else
	   		MessageInterface::ShowMessage(" sensor = NULL\n");
	   }

	   for(std::vector<Hardware*>::iterator hw = this->participantHardware[1].begin();
	   		hw != this->participantHardware[1].end(); ++hw)
	   {
	   	if ((*hw) != NULL)
	   	{
	   		if ((*hw)->GetTypeName() == "Transponder")
	   			objList3.push_back(*hw);
	   	}
	   	else
	   		MessageInterface::ShowMessage(" sensor = NULL\n");
	   }

	   if (objList1.size() != 1)
	   {
	   	MessageInterface::ShowMessage("The first participant does not have only 1 transmitter to send signal.\n");
	      throw new MeasurementException("The first participant does not have only 1 transmitter to send signal.\n");
	   }
	   if (objList2.size() != 1)
	   {
	   	MessageInterface::ShowMessage("The first participant does not have only 1 receiver to receive signal.\n");
	      throw new MeasurementException("The first participant does not have only 1 receiver to receive signal.\n");
	   }
	   if (objList3.size() != 1)
	   {
	   	MessageInterface::ShowMessage("The second participant does not have only 1 transponder to transpond signal.\n");
  			throw new MeasurementException("The second participant does not have only 1 transponder to transpond signal.\n");
	   }

	   Transmitter* 	gsTransmitter 	= (Transmitter*)objList1[0];
	   Receiver* 		gsReceiver 		= (Receiver*)objList2[0];
	   Transponder* 	scTransponder 	= (Transponder*)objList3[0];
	   if (gsTransmitter == NULL)
	   {
	   	MessageInterface::ShowMessage("Transmitter is NULL object.\n");
	   	throw new GmatBaseException("Transmitter is NULL object.\n");
	   }
	   if (gsReceiver == NULL)
	   {
	   	MessageInterface::ShowMessage("Receiver is NULL object.\n");
	   	throw new GmatBaseException("Receiver is NULL object.\n");
	   }
	   if (scTransponder == NULL)
	   {
	   	MessageInterface::ShowMessage("Transponder is NULL object.\n");
	   	throw new GmatBaseException("Transponder is NULL object.\n");
	   }

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("   List of sensors: %s, %s, %s\n",
					gsTransmitter->GetName().c_str(), gsReceiver->GetName().c_str(),
					scTransponder->GetName().c_str());
		#endif


	   // 7. Get frequency from transmitter of ground station (participants[0])
	   Signal* uplinkSignal = gsTransmitter->GetSignal();
	   Real uplinkFreq = uplinkSignal->GetValue();

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("   UpLink signal frequency = %.12lf MHz\n", uplinkFreq);
		#endif

	   // 8. Calculate media correction for uplink leg:
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("      Media correction for uplink leg\n");
      #endif
      Real roundTripTime = ((uplinkRange + downlinkRange)*GmatMathConstants::KM_TO_M/GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM)/GmatTimeConstants::SECS_PER_DAY;
      // DO NOT LEAVE THIS TYPE OF MESSAGE IN THE CODE WITHOUT #ifdef WRAPPERS!!!
      //MessageInterface::ShowMessage("Round trip time = %.12lf\n", roundTripTime);
      RealArray uplinkCorrection = CalculateMediaCorrection(uplinkFreq, r1, r2, currentMeasurement.epoch - roundTripTime);
      Real uplinkRangeCorrection = uplinkCorrection[0]/GmatMathConstants::KM_TO_M;
      Real uplinkRealRange = uplinkRange + uplinkRangeCorrection;
		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("      Uplink range correction = %.12lf km\n",uplinkRangeCorrection);
			MessageInterface::ShowMessage("      Uplink real range = %.12lf km\n",uplinkRealRange);
		#endif

		// 9. Doppler shift the frequency from the transmitter using uplinkRangeRate:
	   Real uplinkDSFreq = (1 - uplinkRangeRate*GmatMathConstants::KM_TO_M/GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM)*uplinkFreq;

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("    Uplink Doppler shift frequency = %.12lf MHz\n", uplinkDSFreq);
		#endif

	   // 10.Set frequency for the input signal of transponder
	   Signal* inputSignal = scTransponder->GetSignal(0);
	   inputSignal->SetValue(uplinkDSFreq);
	   scTransponder->SetSignal(inputSignal, 0);

	   // 11. Check the transponder feasibility to receive the input signal:
	   if (scTransponder->IsFeasible(0) == false)
	   {
	   	 currentMeasurement.isFeasible = false;
	   	 currentMeasurement.value[0] = 0;
	   	 MessageInterface::ShowMessage("The transponder is unfeasible to receive uplink signal.\n");
	   	 throw new GmatBaseException("The transponder is unfeasible to receive uplink signal.\n");
	   }

	   // 12. Get frequency of transponder output signal
	   Signal* outputSignal = scTransponder->GetSignal(1);
	   Real downlinkFreq = outputSignal->GetValue();

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("    Downlink frequency = %.12lf Mhz\n", downlinkFreq);
		#endif

	   // 13. Doppler shift the transponder output frequency by the downlinkRangeRate:
	   Real downlinkDSFreq = (1 - downlinkRangeRate*GmatMathConstants::KM_TO_M/GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM)*downlinkFreq;

	   #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("    Downlink Doppler shift frequency = %.12lf MHz\n", downlinkDSFreq);
		#endif

	   // 14. Set frequency on receiver
	   Signal* downlinkSignal = gsReceiver->GetSignal();
	   downlinkSignal->SetValue(downlinkDSFreq);

	   // 15. Check the receiver feasibility to receive the downlink signal
	   if (gsReceiver->IsFeasible() == false)
	   {
	   	 currentMeasurement.isFeasible = false;
	   	 currentMeasurement.value[0] = 0;
	   	 throw new MeasurementException("The receiver is unfeasible to receive downlink signal.\n");
	   }

	   // 16. Calculate media correction for downlink leg:
	   #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
	      MessageInterface::ShowMessage("      Media correction for downlink leg\n");
	   #endif
	   RealArray downlinkCorrection = CalculateMediaCorrection(downlinkDSFreq, r3, r4, currentMeasurement.epoch);
	   Real downlinkRangeCorrection = downlinkCorrection[0]/GmatMathConstants::KM_TO_M;
	   Real downlinkRealRange = downlinkRange + downlinkRangeCorrection;
		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("      Downlink range correction = %.12lf km\n",downlinkRangeCorrection);
			MessageInterface::ShowMessage("      Downlink real range = %.12lf km\n",downlinkRealRange);
		#endif


	   // 17. Calculate uplink time and down link time: (Is it needed???)
	   uplinkTime   = uplinkRealRange*GmatMathConstants::KM_TO_M / GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM;
	   downlinkTime = downlinkRealRange*GmatMathConstants::KM_TO_M / GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM;

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("    Uplink time = %.12lf s\n",uplinkTime);
			MessageInterface::ShowMessage("    Downlink time = %.12lf s\n",downlinkTime);
		#endif

	   // 18. Calculate real range
	   Real realRange = uplinkRealRange + downlinkRealRange +
	   		targetDelay*GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM / GmatMathConstants::KM_TO_M;
	   
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Calculated real range = %.12lf km\n", realRange/2);
      #endif

	   // 19. Set value for currentMeasurement
	   currentMeasurement.value[0] = realRange / 2.0;
      currentMeasurement.isFeasible = true;


      #ifdef PRELIMINARY_DERIVATIVE_CHECK
         MessageInterface::ShowMessage("Participants:\n ");
         for (UnsignedInt i = 0; i < participants.size(); ++i)
            MessageInterface::ShowMessage("   %d: %s of type %s\n", i,
                  participants[i]->GetName().c_str(),
                  participants[i]->GetTypeName().c_str());

         Integer id = participants[1]->GetType() * 250 +
               participants[1]->GetParameterID("CartesianX");
         CalculateMeasurementDerivatives(participants[1], id);
      #endif

      retval = true;
   }

   return retval;
}
示例#4
0
//------------------------------------------------------------------------------
bool DSNTwoWayRange::Evaluate(bool withEvents)
{
   bool retval = false;

   if (!initialized)
      InitializeMeasurement();

   #ifdef DEBUG_RANGE_CALC
      MessageInterface::ShowMessage("Entered DSNTwoWayRange::Evaluate(%s)\n",
            (withEvents ? "true" : "false"));
      MessageInterface::ShowMessage("  ParticipantCount: %d\n",
            participants.size());
   #endif

   if (withEvents == false)
   {
      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("DSN 2-Way Range Calculation without "
               "events\n");
      #endif

      #ifdef VIEW_PARTICIPANT_STATES
         DumpParticipantStates("++++++++++++++++++++++++++++++++++++++++++++\n"
               "Evaluating DSN 2-Way Range without events");
      #endif

      CalculateRangeVectorInertial();
      Rvector3 outState;

      // Set feasibility off of topocentric horizon, set by the Z value in topo
      // coords
      std::string updateAll = "All";
      UpdateRotationMatrix(currentMeasurement.epoch, updateAll);
      outState = R_o_j2k * rangeVecInertial;
      currentMeasurement.feasibilityValue = outState[2];

      #ifdef CHECK_PARTICIPANT_LOCATIONS
         MessageInterface::ShowMessage("Evaluating without events\n");
         MessageInterface::ShowMessage("Calculating DSN 2-Way Range at epoch "
               "%.12lf\n", currentMeasurement.epoch);
         MessageInterface::ShowMessage("   J2K Location of %s, id = '%s':  %s",
               participants[0]->GetName().c_str(),
               currentMeasurement.participantIDs[0].c_str(),
               p1Loc.ToString().c_str());
         MessageInterface::ShowMessage("   J2K Location of %s, id = '%s':  %s",
               participants[1]->GetName().c_str(),
               currentMeasurement.participantIDs[1].c_str(),
               p2Loc.ToString().c_str());
         Rvector3 bfLoc = R_o_j2k * p1Loc;
         MessageInterface::ShowMessage("   BodyFixed Location of %s:  %s",
               participants[0]->GetName().c_str(),
               bfLoc.ToString().c_str());
         bfLoc = R_o_j2k * p2Loc;
         MessageInterface::ShowMessage("   BodyFixed Location of %s:  %s\n",
               participants[1]->GetName().c_str(),
               bfLoc.ToString().c_str());
      #endif

      if (currentMeasurement.feasibilityValue > 0.0)
      {
         currentMeasurement.isFeasible = true;
         currentMeasurement.value[0] = rangeVecInertial.GetMagnitude();
         currentMeasurement.eventCount = 2;

         SetHardwareDelays(false);

         retval = true;
      }
      else
      {
         currentMeasurement.isFeasible = false;
         currentMeasurement.value[0] = 0.0;
         currentMeasurement.eventCount = 0;
      }

      #ifdef DEBUG_RANGE_CALC
         MessageInterface::ShowMessage("Calculating Range at epoch %.12lf\n",
               currentMeasurement.epoch);
         MessageInterface::ShowMessage("   Location of %s, id = '%s':  %s",
               participants[0]->GetName().c_str(),
               currentMeasurement.participantIDs[0].c_str(),
               p1Loc.ToString().c_str());
         MessageInterface::ShowMessage("   Location of %s, id = '%s':  %s",
               participants[1]->GetName().c_str(),
               currentMeasurement.participantIDs[1].c_str(),
               p2Loc.ToString().c_str());
         MessageInterface::ShowMessage("   Range Vector:  %s\n",
               rangeVecInertial.ToString().c_str());
         MessageInterface::ShowMessage("   R(Groundstation) dot RangeVec =  %lf\n",
               currentMeasurement.feasibilityValue);
         MessageInterface::ShowMessage("   Feasibility:  %s\n",
               (currentMeasurement.isFeasible ? "true" : "false"));
         MessageInterface::ShowMessage("   Range is %.12lf\n",
               currentMeasurement.value[0]);
         MessageInterface::ShowMessage("   EventCount is %d\n",
               currentMeasurement.eventCount);
      #endif

      #ifdef SHOW_RANGE_CALC
         MessageInterface::ShowMessage("Range at epoch %.12lf is ",
               currentMeasurement.epoch);
         if (currentMeasurement.isFeasible)
            MessageInterface::ShowMessage("feasible, value = %.12lf\n",
               currentMeasurement.value[0]);
         else
            MessageInterface::ShowMessage("not feasible\n");
      #endif
   }
   else
   {
      // Calculate the corrected range measurement
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("\n\n DSN 2-Way Range Calculation:\n");
      #endif

      #ifdef VIEW_PARTICIPANT_STATES_WITH_EVENTS
         DumpParticipantStates("********************************************\n"
               "Evaluating DSN 2-Way Range with located events");
      #endif

      // 1. Get the range from the down link
      Rvector3 r1, r2;
	  Real t1, t2;
      r1 = downlinkLeg.GetPosition(participants[0]);
      r2 = downlinkLeg.GetPosition(participants[1]);
	  t1 = downlinkLeg.GetEventData((GmatBase*) participants[0]).epoch;
	  t2 = downlinkLeg.GetEventData((GmatBase*) participants[1]).epoch;
	  Rmatrix33 mt = downlinkLeg.GetEventData((GmatBase*) participants[0]).rInertial2obj.Transpose();
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
	     MessageInterface::ShowMessage("1. Get downlink leg range:\n");
         MessageInterface::ShowMessage("   Ground station position in FK5: r1 = (%f, %f, %f)km  at epoch = %18.12lf\n", r1.Get(0), r1.Get(1), r1.Get(2), t1);
         MessageInterface::ShowMessage("   Spacecraft position in FK5    : r2 = (%f, %f, %f)km  at epoch = %18.12lf\n", r2.Get(0), r2.Get(1), r2.Get(2), t2);
		 MessageInterface::ShowMessage("   Transformation matrix from Earth fixed coordinate system to FK5 coordinate system at epoch = %18.12lf:\n", t1);
		 MessageInterface::ShowMessage("                %18.12lf  %18.12lf  %18.12lf\n", mt(0,0), mt(0,1), mt(0,2));
		 MessageInterface::ShowMessage("                %18.12lf  %18.12lf  %18.12lf\n", mt(1,0), mt(1,1), mt(1,2));
		 MessageInterface::ShowMessage("                %18.12lf  %18.12lf  %18.12lf\n", mt(2,0), mt(2,1), mt(2,2));
      #endif
      Rvector3 downlinkVector = r2 - r1;		// rVector = r2 - r1;
      downlinkRange = downlinkVector.GetMagnitude();
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Downlink Range = r2-r1:  %.12lf km\n",
               downlinkRange);
      #endif


 	   // 2. Calculate down link range rate:
      Rvector3 p1V = downlinkLeg.GetVelocity(participants[0]);
      Rvector3 p2V = downlinkLeg.GetVelocity(participants[1]);
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
	     MessageInterface::ShowMessage("2. Get downlink leg range rate:\n");
         MessageInterface::ShowMessage("   Ground station velocity in FK5: p1V = (%f, %f, %f)km/s\n", p1V.Get(0), p1V.Get(1), p1V.Get(2));
         MessageInterface::ShowMessage("   Spacecraft velocity in FK5    : p2V = (%f, %f, %f)km/s\n", p2V.Get(0), p2V.Get(1), p2V.Get(2));
      #endif
      // @todo Relative origin velocities need to be subtracted when the origins
      // differ; check and fix that part using r12_j2k_vel here.  It's not yet
      // incorporated because we need to handle the different epochs for the
      // bodies, and we ought to do this part in barycentric coordinates
      Rvector downRRateVec = p2V - p1V /* - r12_j2k_vel*/;
      Rvector3 rangeUnit = downlinkVector.GetUnitVector();
      downlinkRangeRate = downRRateVec * rangeUnit;
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Downlink Range Rate:  %.12lf km/s\n",
               downlinkRangeRate);
      #endif


      // 3. Get the range from the uplink
      Rvector3 r3, r4;
	  Real t3, t4;
      r3 = uplinkLeg.GetPosition(participants[0]);
      r4 = uplinkLeg.GetPosition(participants[1]);
	  t3 = uplinkLeg.GetEventData((GmatBase*) participants[0]).epoch;
	  t4 = uplinkLeg.GetEventData((GmatBase*) participants[1]).epoch;
	  Rmatrix33 mt1 = uplinkLeg.GetEventData((GmatBase*) participants[0]).rInertial2obj.Transpose();
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
	     MessageInterface::ShowMessage("3. Get uplink leg range:\n");
         MessageInterface::ShowMessage("   Spacecraft position in FK5    : r4 = (%f, %f, %f)km   at epoch = %18.12lf\n", r4.Get(0), r4.Get(1), r4.Get(2), t4);
         MessageInterface::ShowMessage("   Ground station position in FK5: r3 = (%f, %f, %f)km   at epoch = %18.12lf\n", r3.Get(0), r3.Get(1), r3.Get(2), t3);
		 MessageInterface::ShowMessage("   Transformation matrix from Earth fixed coordinate system to FK5 coordinate system at epoch = %18.12lf:\n", t3);
		 MessageInterface::ShowMessage("                %18.12lf  %18.12lf  %18.12lf\n", mt1(0,0), mt1(0,1), mt1(0,2));
		 MessageInterface::ShowMessage("                %18.12lf  %18.12lf  %18.12lf\n", mt1(1,0), mt1(1,1), mt1(1,2));
		 MessageInterface::ShowMessage("                %18.12lf  %18.12lf  %18.12lf\n", mt1(2,0), mt1(2,1), mt1(2,2));
      #endif
      Rvector3 uplinkVector = r4 - r3;
      uplinkRange = uplinkVector.GetMagnitude();
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Uplink Range = r4-r3:  %.12lf km\n",
               uplinkRange);
      #endif


   	// 4. Calculate up link range rate
      Rvector3 p3V = uplinkLeg.GetVelocity(participants[0]);
      Rvector3 p4V = uplinkLeg.GetVelocity(participants[1]);
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
	     MessageInterface::ShowMessage("4. Get uplink leg range rate:\n");
         MessageInterface::ShowMessage("   Ground station velocity in FK5: p3V = (%f, %f, %f)km/s\n", p3V.Get(0), p3V.Get(1), p3V.Get(2));
         MessageInterface::ShowMessage("   Spacecraft velocity in FK5    : p4V = (%f, %f, %f)km/s\n", p4V.Get(0), p4V.Get(1), p4V.Get(2));
      #endif
      // @todo Relative origin velocities need to be subtracted when the origins
      // differ; check and fix that part using r12_j2k_vel here.  It's not yet
      // incorporated because we need to handle the different epochs for the
      // bodies, and we ought to do this part in barycentric coordinates
      Rvector upRRateVec = p4V - p3V /* - r12_j2k_vel*/ ;
      rangeUnit = uplinkVector.GetUnitVector();
      uplinkRangeRate = upRRateVec * rangeUnit;
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("   Uplink Range Rate:  %.12lf km/s\n",
               uplinkRangeRate);
      #endif

      // 4.1. Target range rate: Do we need this as well?
      targetRangeRate = (downlinkRangeRate + uplinkRangeRate) / 2.0;

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("   Target Range Rate:  %.12lf km/s\n",
						targetRangeRate);
		#endif


		// 5. Get sensors used in DSN 2-ways range
	   if (participantHardware.empty()||
	   		((!participantHardware.empty())&&
	   		  participantHardware[0].empty()&&
	   		  participantHardware[1].empty()
	   		)
	   	)
	   {
         // DO NOT LEAVE THIS RAW IN A SOURCE FILE!!!
	   	// MessageInterface::ShowMessage("    Ideal measurement (no hardware delay and no media correction involve):\n");

		   // Calculate uplink time and down link time: (Is it needed???)
		   uplinkTime   = uplinkRange*GmatMathConstants::KM_TO_M / GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM;
		   downlinkTime = downlinkRange*GmatMathConstants::KM_TO_M / GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM;
		   #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
		      MessageInterface::ShowMessage("  Ideal measurement (no hardware delay and no media correction involve):\n");
			  MessageInterface::ShowMessage("    Uplink time = %.12lf s\n",uplinkTime);
			  MessageInterface::ShowMessage("    Downlink time = %.12lf s\n",downlinkTime);
		   #endif

		   // Calculate real range
		   Real freqFactor = GetFrequencyFactor(frequency);	// Notice that: unit of "frequency" varaibel is Hz (not MHz)
		   Real realTravelTime = uplinkTime + downlinkTime + receiveDelay + transmitDelay + targetDelay;	// unit: second
		   Real realRangeKm = 0.5 *realTravelTime * GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM/1000.0;    // unit: km
		   Real realRange = realTravelTime * freqFactor;													// unit: no unit

		   #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
		      MessageInterface::ShowMessage("   Frequency = %.12lf MHz (This value is set to the default value in PhysicalMeasurement class due to no hardware used.)\n", frequency/1.0e6);
			  MessageInterface::ShowMessage("   Frequency factor = %.12lf MHz\n", freqFactor/1.0e6);
	          MessageInterface::ShowMessage("   Range in km = %.12lf km\n", realRangeKm);
			  MessageInterface::ShowMessage("   uplinkRange = %lfkm   downlinkRange = %lfkm\n", uplinkRange, downlinkRange);
			  MessageInterface::ShowMessage("   receiveDelay = %lfm   transmitDelay = %lfm   targetDelay = %lfm\n", receiveDelay*GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM, transmitDelay*GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM, targetDelay*GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM);
	          MessageInterface::ShowMessage("   Range = %.12lf (It has no unit)\n", realRange);
	       #endif

	      // Set value for currentMeasurement
		   currentMeasurement.value[0] = realRange;
	      currentMeasurement.isFeasible = true;

	      return true;
	   }

		ObjectArray objList1;
		ObjectArray objList2;
		ObjectArray objList3;
		//			objList1 := all transmitters in participantHardware list
		//			objList2 := all receivers in participantHardware list
		//			objList3 := all transponders in participantHardware list
		for(std::vector<Hardware*>::iterator hw = this->participantHardware[0].begin();
		  		hw != this->participantHardware[0].end(); ++hw)
		{
		 	if ((*hw) != NULL)
		  	{
		  		if ((*hw)->GetTypeName() == "Transmitter")
		  			objList1.push_back(*hw);
		  		if ((*hw)->GetTypeName() == "Receiver")
		  			objList2.push_back(*hw);
		  	}
		  	else
		  		MessageInterface::ShowMessage(" sensor = NULL\n");
		}

		for(std::vector<Hardware*>::iterator hw = this->participantHardware[1].begin();
		  		hw != this->participantHardware[1].end(); ++hw)
		{
		  	if ((*hw) != NULL)
		  	{
		  		if ((*hw)->GetTypeName() == "Transponder")
		  			objList3.push_back(*hw);
		  	}
		  	else
		  		MessageInterface::ShowMessage(" sensor = NULL\n");
		}

		if (objList1.size() != 1)
		{
		  	MessageInterface::ShowMessage("The first participant does not have only 1 transmitter to send signal.\n");
		   throw new MeasurementException("The first participant does not have only 1 transmitter to send signal.\n");
		}
		if (objList2.size() != 1)
		{
		 	MessageInterface::ShowMessage("The first participant does not have only 1 receiver to receive signal.\n");
		   throw new MeasurementException("The first participant does not have only 1 receiver to receive signal.\n");
		}
		if (objList3.size() != 1)
		{
		  	MessageInterface::ShowMessage("The second participant does not have only 1 transponder to transpond signal.\n");
		  	throw new MeasurementException("The second participant does not have only 1 transponder to transpond signal.\n");
		}

	   Transmitter* 	gsTransmitter 	= (Transmitter*)objList1[0];
	   Receiver* 		gsReceiver 		= (Receiver*)objList2[0];
	   Transponder* 	scTransponder 	= (Transponder*)objList3[0];
	   if (gsTransmitter == NULL)
	   {
	   	MessageInterface::ShowMessage("Transmitter is NULL object.\n");
	   	throw new GmatBaseException("Transmitter is NULL object.\n");
	   }
	   if (gsReceiver == NULL)
	   {
	   	MessageInterface::ShowMessage("Receiver is NULL object.\n");
	   	throw new GmatBaseException("Receiver is NULL object.\n");
	   }
	   if (scTransponder == NULL)
	   {
	   	MessageInterface::ShowMessage("Transponder is NULL object.\n");
	   	throw new GmatBaseException("Transponder is NULL object.\n");
	   }

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
	        MessageInterface::ShowMessage("5. Sensors, delays, and signals:\n");
			MessageInterface::ShowMessage("   List of sensors: %s, %s, %s\n",
				gsTransmitter->GetName().c_str(), gsReceiver->GetName().c_str(),
				scTransponder->GetName().c_str());
		#endif


		// 6. Get transmitter, receiver, and transponder delays:
		transmitDelay = gsTransmitter->GetDelay();
		receiveDelay = gsReceiver->GetDelay();
		targetDelay = scTransponder->GetDelay();

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("   Transmitter delay = %le s\n", gsTransmitter->GetDelay());
			MessageInterface::ShowMessage("   Receiver delay = %le s\n", gsReceiver->GetDelay());
			MessageInterface::ShowMessage("   Transponder delay = %le s\n", scTransponder->GetDelay());
		#endif


		// 7. Get frequency from transmitter of ground station (participants[0])
		Signal* uplinkSignal = gsTransmitter->GetSignal();
		Real uplinkFreq = uplinkSignal->GetValue();


        // 8. Calculate media correction for uplink leg:
        #ifdef DEBUG_RANGE_CALC_WITH_EVENTS   
           MessageInterface::ShowMessage("6. Media correction for uplink leg\n");
		   MessageInterface::ShowMessage("   UpLink signal frequency = %.12lf MHz\n", uplinkFreq);
        #endif
        Real roundTripTime = ((uplinkRange + downlinkRange)*GmatMathConstants::KM_TO_M/GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM)/GmatTimeConstants::SECS_PER_DAY;
        RealArray uplinkCorrection = CalculateMediaCorrection(uplinkFreq, r1, r2, currentMeasurement.epoch - roundTripTime);
        Real uplinkRangeCorrection = uplinkCorrection[0]/GmatMathConstants::KM_TO_M;
        Real uplinkRealRange = uplinkRange + uplinkRangeCorrection;
		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("   Uplink range correction = %.12lf km\n",uplinkRangeCorrection);
			MessageInterface::ShowMessage("   Uplink real range = %.12lf km\n",uplinkRealRange);
		#endif


		// 9. Doppler shift the frequency from the transmitter using uplinkRangeRate:
	   Real uplinkDSFreq = (1 - uplinkRangeRate*GmatMathConstants::KM_TO_M/GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM)*uplinkFreq;

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
	        MessageInterface::ShowMessage("7. Transponder input and output frequencies\n");
			MessageInterface::ShowMessage("   Uplink Doppler shift frequency = %.12lf MHz\n", uplinkDSFreq);
		#endif


	   // 10.Set frequency for the input signal of transponder
	   Signal* inputSignal = scTransponder->GetSignal(0);
	   inputSignal->SetValue(uplinkDSFreq);
	   scTransponder->SetSignal(inputSignal, 0);


	   // 11. Check the transponder feasibility to receive the input signal:
	   if (scTransponder->IsFeasible(0) == false)
	   {
	   	 currentMeasurement.isFeasible = false;
	   	 currentMeasurement.value[0] = 0;
	   	 MessageInterface::ShowMessage("The transponder is unfeasible to receive uplink signal.\n");
	   	 throw new GmatBaseException("The transponder is unfeasible to receive uplink signal.\n");
	   }


	   // 12. Get frequency of transponder output signal
	   Signal* outputSignal = scTransponder->GetSignal(1);
	   Real downlinkFreq = outputSignal->GetValue();

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("  Downlink frequency = %.12lf Mhz\n", downlinkFreq);
		#endif


	   // 13. Doppler shift the transponder output frequency by the downlinkRangeRate:
	   Real downlinkDSFreq = (1 - downlinkRangeRate*GmatMathConstants::KM_TO_M/GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM)*downlinkFreq;

	   #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("  Downlink Doppler shift frequency = %.12lf MHz\n", downlinkDSFreq);
		#endif


	   // 14. Set frequency on receiver
	   Signal* downlinkSignal = gsReceiver->GetSignal();
	   downlinkSignal->SetValue(downlinkDSFreq);


	   // 15. Check the receiver feasibility to receive the downlink signal
	   if (gsReceiver->IsFeasible() == false)
	   {
	   	 currentMeasurement.isFeasible = false;
	   	 currentMeasurement.value[0] = 0;
		 MessageInterface::ShowMessage("The receiver is unfeasible to receive downlink signal.\n");
	   	 throw new MeasurementException("The receiver is unfeasible to receive downlink signal.\n");
	   }


	   // 16. Calculate media correction for downlink leg:
      #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
         MessageInterface::ShowMessage("8. Media correction for downlink leg\n");
      #endif
	   RealArray downlinkCorrection = CalculateMediaCorrection(downlinkDSFreq, r3, r4, currentMeasurement.epoch);
	   Real downlinkRangeCorrection = downlinkCorrection[0]/GmatMathConstants::KM_TO_M;
	   Real downlinkRealRange = downlinkRange + downlinkRangeCorrection;
		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
			MessageInterface::ShowMessage("   Downlink range correction = %.12lf km\n",downlinkRangeCorrection);
			MessageInterface::ShowMessage("   Downlink real range = %.12lf km\n",downlinkRealRange);
		#endif

	   // 17. Calculate uplink time and down link time: (Is it needed???)
	   uplinkTime   = uplinkRealRange*GmatMathConstants::KM_TO_M / GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM;
	   downlinkTime = downlinkRealRange*GmatMathConstants::KM_TO_M / GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM;

		#ifdef DEBUG_RANGE_CALC_WITH_EVENTS
	        MessageInterface::ShowMessage("9. Travel time:\n");
			MessageInterface::ShowMessage("   Uplink time = %.12lf s\n",uplinkTime);
			MessageInterface::ShowMessage("   Downlink time = %.12lf s\n",downlinkTime);
		#endif


	   // 18. Calculate real range
		//	   Real realRange = ((upRange + downRange) /
		//            (GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM / GmatMathConstants::KM_TO_M) +
		//            receiveDelay + transmitDelay + targetDelay) * freqFactor;

	   // Real freqFactor = GetFrequencyFactor(frequency);
	   Real freqFactor = GetFrequencyFactor(uplinkFreq*1.0e6);		// Notice that: unit of "uplinkFreq" is MHz (not Hz)
  	   Real realTravelTime = uplinkTime + downlinkTime + receiveDelay + transmitDelay + targetDelay;    // unit: second
	   Real realRangeKm = 0.5*realTravelTime * GmatPhysicalConstants::SPEED_OF_LIGHT_VACUUM/1000.0;		// unit: km
       Real realRange = realTravelTime * freqFactor;													// unit: no unit

	   #ifdef DEBUG_RANGE_CALC_WITH_EVENTS
		  MessageInterface::ShowMessage("   Frequency factor = %.12lf MHz\n", freqFactor/1.0e6);
		  MessageInterface::ShowMessage("   Calculated real range in km = %.12lf km\n", realRangeKm);
          MessageInterface::ShowMessage("   Calculated real range = %.12lf (It has no unit)\n", realRange);
       #endif



	   // 19. Set value for currentMeasurement
//	   currentMeasurement.value[0] = realRange;
      currentMeasurement.value[0] = realRangeKm;
      currentMeasurement.isFeasible = true;

      retval = true;
   }

   return retval;
}