コード例 #1
0
      /* Returns a satTypeValueMap object, adding the new data generated when
       * calling this object.
       *
       * @param time      Epoch corresponding to the data.
       * @param gData     Data object holding the data.
       */
   satTypeValueMap& ComputeSatPCenter::Process(const DayTime& time,
                                           satTypeValueMap& gData)
      throw(ProcessingException)
   {

      try
      {

            // Compute Sun position at this epoch
         SunPosition sunPosition;
         Triple sunPos(sunPosition.getPosition(time));

            // Define a Triple that will hold satellite position, in ECEF
         Triple svPos(0.0, 0.0, 0.0);

         SatIDSet satRejectedSet;

            // Loop through all the satellites
         satTypeValueMap::iterator it;
         for (it = gData.begin(); it != gData.end(); ++it)
         {

               // Use ephemeris if satellite position is not already computed
            if( ( (*it).second.find(TypeID::satX) == (*it).second.end() ) ||
                ( (*it).second.find(TypeID::satY) == (*it).second.end() ) ||
                ( (*it).second.find(TypeID::satZ) == (*it).second.end() ) )
            {

               if(pEphemeris==NULL)
               {

                     // If ephemeris is missing, then remove all satellites
                  satRejectedSet.insert( (*it).first );

                  continue;
               }
               else
               {

                     // Try to get satellite position
                     // if it is not already computed
                  try
                  {
                        // For our purposes, position at receive time
                        // is fine enough
                     Xvt svPosVel(pEphemeris->getXvt( (*it).first, time ));

                        // If everything is OK, then continue processing.
                     svPos[0] = svPosVel.x.theArray[0];
                     svPos[1] = svPosVel.x.theArray[1];
                     svPos[2] = svPosVel.x.theArray[2];

                  }
                  catch(...)
                  {

                        // If satellite is missing, then schedule it
                        // for removal
                     satRejectedSet.insert( (*it).first );

                     continue;
                  }

               }

            }
            else
            {

                  // Get satellite position out of GDS
               svPos[0] = (*it).second[TypeID::satX];
               svPos[1] = (*it).second[TypeID::satY];
               svPos[2] = (*it).second[TypeID::satZ];

            }  // End of 'if( ( (*it).second.find(TypeID::satX) == ...'


               // Let's get the satellite antenna phase correction value in
               // meters, and insert it in the GNSS data structure.
            (*it).second[TypeID::satPCenter] =
               getSatPCenter((*it).first, time, svPos, sunPos);

         }  // End of 'for (it = gData.begin(); it != gData.end(); ++it)'

            // Remove satellites with missing data
         gData.removeSatID(satRejectedSet);

         return gData;

      }
      catch(Exception& u)
      {

            // Throw an exception if something unexpected happens
         ProcessingException e( getClassName() + ":"
                                + StringUtils::asString( getIndex() ) + ":"
                                + u.what() );

         GPSTK_THROW(e);

      }

   }  // End of method 'ComputeSatPCenter::Process()'
コード例 #2
0
ファイル: EclipsedSatFilter.cpp プロジェクト: PPNav/GPSTk
      /* Returns a satTypeValueMap object, adding the new data generated
       *  when calling this object.
       *
       * @param epoch     Time of observations.
       * @param gData     Data object holding the data.
       */
   satTypeValueMap& EclipsedSatFilter::Process( const CommonTime& epoch,
                                                satTypeValueMap& gData )
      throw(ProcessingException)
   {

      try
      {

         SatIDSet satRejectedSet;

            // Set the threshold to declare that satellites are in eclipse
            // threshold = cos(180 - coneAngle/2)
         double threshold( std::cos(PI - coneAngle/2.0*DEG_TO_RAD) );

            // Compute Sun position at this epoch, and store it in a Triple
         SunPosition sunPosition;
         Triple sunPos(sunPosition.getPosition(epoch));

            // Define a Triple that will hold satellite position, in ECEF
         Triple svPos(0.0, 0.0, 0.0);

            // Loop through all the satellites
         satTypeValueMap::iterator it;
         for (it = gData.begin(); it != gData.end(); ++it) 
         {
               // Check if satellite position is not already computed
            if( ( (*it).second.find(TypeID::satX) == (*it).second.end() ) ||
                ( (*it).second.find(TypeID::satY) == (*it).second.end() ) ||
                ( (*it).second.find(TypeID::satZ) == (*it).second.end() ) )
            {

                  // If satellite position is missing, then schedule this 
                  // satellite for removal
               satRejectedSet.insert( (*it).first );
               continue;
            }
            else
            {
                  // Get satellite position out of GDS
               svPos[0] = (*it).second[TypeID::satX];
               svPos[1] = (*it).second[TypeID::satY];
               svPos[2] = (*it).second[TypeID::satZ];
            }

               // Unitary vector from Earth mass center to satellite
            Triple rk( svPos.unitVector() );

               // Unitary vector from Earth mass center to Sun
            Triple ri( sunPos.unitVector() );

               // Get dot product between unitary vectors = cosine(angle)
            double cosAngle(ri.dot(rk));

               // Check if satellite is within shadow
            if(cosAngle <= threshold)
            {
                  // If satellite is eclipsed, then schedule it for removal
               satRejectedSet.insert( (*it).first );

                  // Keep track of last known epoch the satellite was in eclipse
               shadowEpoch[(*it).first] = epoch;

               continue;
            }
            else
            {
                  // Maybe the satellite is out fo shadow, but it was recently
                  // in eclipse. Check also that.
               if( shadowEpoch.find( (*it).first ) != shadowEpoch.end() )
               {
                     // If satellite was recently in eclipse, check if elapsed
                     // time is less or equal than postShadowPeriod
                  if( std::abs( ( epoch - shadowEpoch[(*it).first] ) ) <=
                                postShadowPeriod )
                  {
                        // Satellite left shadow, but too recently. Delete it
                     satRejectedSet.insert( (*it).first );
                  }
                  else
                  {
                        // If satellite left shadow a long time ago, set it free
                     shadowEpoch.erase( (*it).first );
                  }
               }
            }

         }

            // Remove satellites with missing data
         gData.removeSatID(satRejectedSet);

         return gData;

      }
      catch(Exception& u)
      {
            // Throw an exception if something unexpected happens
         ProcessingException e( getClassName() + ":"
                                + u.what() );

         GPSTK_THROW(e);

      }

   }  // End of 'EclipsedSatFilter::Process()'