//============================================================================
//
//  This file is part of GPSTk, the GPS Toolkit.
//
//  The GPSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
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//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GPSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//  
//  Copyright 2004, The University of Texas at Austin
//  Dagoberto Salazar - gAGE ( http://www.gage.es ). 2007, 2008, 2011
//
//============================================================================

//============================================================================
//
//This software developed by Applied Research Laboratories at the University of
//Texas at Austin, under contract to an agency or agencies within the U.S. 
//Department of Defense. The U.S. Government retains all rights to use,
//duplicate, distribute, disclose, or release this software. 
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//Pursuant to DoD Directive 523024 
//
// DISTRIBUTION STATEMENT A: This software has been approved for public 
//                           release, distribution is unlimited.
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//=============================================================================

/**
 * @file ModelObsFixedStation.hpp
 * This is a class to compute modeled (corrected) observations from a
 * reference station (whose position is known), using GNSS data structures.
 */

#ifndef GPSTK_MODELOBSFIXEDSTATION_HPP
#define GPSTK_MODELOBSFIXEDSTATION_HPP

#include "ProcessingClass.hpp"
#include "EphemerisRange.hpp"
#include "EngEphemeris.hpp"
#include "XvtStore.hpp"
#include "GPSEphemerisStore.hpp"
#include "TropModel.hpp"
#include "IonoModelStore.hpp"


namespace gpstk
{

      /// @ingroup GPSsolutions 
      //@{

      /** This class computes modeled (corrected) observations from a
       *  reference station (whose position is known), using GNSS data
       *  structures (GDS).
       *
       * A typical way to use this class follows:
       *
       * @code
       *      // Input observation file stream
       *   RinexObsStream rin("ebre0300.02o");
       *      // Reference position of receiver station
       *   Position nominalPos(4833520.2269, 41537.00768, 4147461.489);
       *
       *      // Some more code and definitions here...
       *
       *   gnssRinex gRin;      // GNSS data structure for fixed station data
       *
       *      // Set defaults of models. A typical C1-based modeling is used
       *   ModelObsFixedStation model( nominalPos,
       *                               ionoStore,
       *                               mopsTM,
       *                               bceStore,
       *                               TypeID::C1,
       *                               true );
       *
       *   while(rin >> gRin)
       *   {
       *
       *         // Apply the model on the GDS
       *      gRin >> model;
       *   }
       *
       * @endcode
       *
       * The "ModelObsFixedStation" object will visit every satellite in
       * the GNSS data structure that is "gRin" and will try to compute
       * its model: Prefit residual, geometric distance, relativity delay,
       * ionospheric/tropospheric corrections, geometry matrix, etc.
       *
       * When used with the ">>" operator, this class returns the same
       * incoming data structure with the extra data inserted along their
       * corresponding satellites. Be warned that if a given satellite does
       * not have the observations required, it will be summarily deleted
       * from the data structure.
       *
       * @sa ModelObs.hpp for modeling data from a moving receiver.
       *
       */
   class ModelObsFixedStation : public ProcessingClass
   {
   public:

         /// Default constructor. Models C1 observations, use TGD,
         /// but doesn't apply atmospheric models
      ModelObsFixedStation()
         : minElev(10.0), useTGD(true), pDefaultIonoModel(NULL),
           pDefaultTropoModel(NULL), defaultObservable(TypeID::C1),
           pDefaultEphemeris(NULL)
      { InitializeValues(); };


         /** Explicit constructor taking as input reference
          *  station coordinates.
          *
          * Those coordinates may be Cartesian (X, Y, Z in meters) or Geodetic
          * (Latitude, Longitude, Altitude), but defaults to Cartesian.
          *
          * @param aRx   first coordinate [ X(m), or latitude (degrees N) ]
          * @param bRx   second coordinate [ Y(m), or longitude (degrees E) ]
          * @param cRx   third coordinate [ Z, height above ellipsoid or
          *              radius, in meters ]
          * @param s     coordinate system (default is Cartesian, may be set
          *              to Geodetic).
          * @param ell   pointer to EllipsoidModel.
          * @param frame Reference frame associated with this position.
          */
      ModelObsFixedStation( const double& aRx,
                            const double& bRx,
                            const double& cRx,
                            Position::CoordinateSystem s = Position::Cartesian,
                            EllipsoidModel *ell = NULL,
                            ReferenceFrame frame = ReferenceFrame::Unknown );


         /// Explicit constructor, taking as input a Position object
         /// containing reference station coordinates.
      ModelObsFixedStation(const Position& RxCoordinates);


         /** Explicit constructor, taking as input reference station
          *  coordinates, default ionospheric and tropospheric models,
          *  ephemeris to be used, default observable and whether TGD will
          *  be computed or not.
          *
          * @param RxCoordinates Reference station coordinates.
          * @param dIonoModel    Ionospheric model to be used by default.
          * @param dTropoModel   Tropospheric model to be used by default.
          * @param dEphemeris    EphemerisStore object to be used by default.
          * @param dObservable   Observable type to be used by default.
          * @param usetgd        Whether TGD will be used by default or not.
          *
          */
      ModelObsFixedStation( const Position& RxCoordinates,
                            IonoModelStore& dIonoModel,
                            TropModel& dTropoModel,
                            XvtStore<SatID>& dEphemeris,
                            const TypeID& dObservable,
                            bool usetgd = true );


         /** Explicit constructor, taking as input reference station
          *  coordinates, default ionospheric model, ephemeris to be used,
          *  default observable and whether TGD will be computed or not.
          *
          * The default tropospheric model will be set to NULL.
          *
          * @param RxCoordinates Reference station coordinates.
          * @param dIonoModel    Ionospheric model to be used by default.
          * @param dEphemeris    EphemerisStore object to be used by default.
          * @param dObservable   Observable type to be used by default.
          * @param usetgd        Whether TGD will be used by default or not.
          *
          */
      ModelObsFixedStation( const Position& RxCoordinates,
                            IonoModelStore& dIonoModel,
                            XvtStore<SatID>& dEphemeris,
                            const TypeID& dObservable,
                            bool usetgd = true );


         /** Explicit constructor, taking as input reference station
          *  coordinates, default tropospheric model, ephemeris to be used,
          *  default observable and whether TGD will be computed or not.
          *
          * The default ionospheric model will be set to NULL.
          *
          * @param RxCoordinates Reference station coordinates.
          * @param dTropoModel   Tropospheric model to be used by default.
          * @param dEphemeris    EphemerisStore object to be used by default.
          * @param dObservable   Observable type to be used by default.
          * @param usetgd        Whether TGD will be used by default or not.
          *
          */
      ModelObsFixedStation( const Position& RxCoordinates,
                            TropModel& dTropoModel,
                            XvtStore<SatID>& dEphemeris,
                            const TypeID& dObservable,
                            bool usetgd = true );


         /** Explicit constructor, taking as input reference station
          *  coordinates, ephemeris to be used, default observable and whether
          *  TGD will be computed or not.
          *
          * Both the tropospheric and ionospheric models will be set to NULL.
          *
          * @param RxCoordinates Reference station coordinates.
          * @param dEphemeris    EphemerisStore object to be used by default.
          * @param dObservable   Observable type to be used by default.
          * @param usetgd        Whether TGD will be used by default or not.
          *
          */
      ModelObsFixedStation( const Position& RxCoordinates,
                            XvtStore<SatID>& dEphemeris,
                            const TypeID& dObservable,
                            bool usetgd = true);


         /** Returns a satTypeValueMap object, adding the new data generated
          *  when calling a modeling object.
          *
          * @param time      Epoch.
          * @param gData     Data object holding the data.
          */
      virtual satTypeValueMap& Process( const CommonTime& time,
                                        satTypeValueMap& gData )
         throw(ProcessingException);


         /** Returns a gnnsSatTypeValue object, adding the new data generated
          *  when calling a modeling object.
          *
          * @param gData    Data object holding the data.
          */
      virtual gnssSatTypeValue& Process(gnssSatTypeValue& gData)
         throw(ProcessingException)
      { Process(gData.header.epoch, gData.body); return gData; };


         /** Returns a gnnsRinex object, adding the new data generated when
          *  calling a modeling object.
          *
          * @param gData    Data object holding the data.
          */
      virtual gnssRinex& Process(gnssRinex& gData)
         throw(ProcessingException)
      { Process(gData.header.epoch, gData.body); return gData; };


         /// Method to get satellite elevation cut-off angle. By default, it
         /// is set to 10 degrees.
      virtual double getMinElev() const
      { return minElev; };


         /// Method to set satellite elevation cut-off angle. By default, it
         /// is set to 10 degrees.
      virtual ModelObsFixedStation& setMinElev(double newElevation)
      { minElev = newElevation; return (*this); };


         /// Method to set if instrumental delays (TGD) will be used or not
         /// in the modeling (it is set to true by default).
      virtual ModelObsFixedStation& setTGD(bool use)
      { useTGD = use; return (*this); };


         /// Method to get a pointer to the default ionospheric model.
      virtual IonoModelStore* getDefaultIonoModel() const
      { return pDefaultIonoModel; };


         /// Method to set a NULL ionospheric model.
      virtual ModelObsFixedStation& setNULLIonoModel()
      { pDefaultIonoModel = NULL; return (*this); };


         /** Method to set the default ionospheric model.
          * @param dIonoModel    Ionospheric model to be used by default.
          */
      virtual ModelObsFixedStation& setDefaultIonoModel(
                                                IonoModelStore& dIonoModel)
      { pDefaultIonoModel = &dIonoModel; return (*this); };


         /// Method to get a pointer to the default tropospheric model.
      virtual TropModel* getDefaultTropoModel() const
      { return pDefaultTropoModel; };


         /// Method to set a NULL tropospheric model.
      virtual ModelObsFixedStation& setNULLTropoModel()
      { pDefaultTropoModel = NULL; return (*this); };


         /** Method to set the default tropospheric model.
          * @param dTropoModel    Tropospheric model to be used by default.
          */
      virtual ModelObsFixedStation& setDefaultTropoModel(
                                                TropModel& dTropoModel)
      { pDefaultTropoModel = &dTropoModel; return (*this); };


         /// Method to get the default observable being used with GNSS
         /// data structures.
      virtual TypeID getDefaultObservable() const
      { return defaultObservable; };


         /** Method to set the default observable to be used when fed with
          *  GNSS data structures.
          * @param type      TypeID object to be used by default
          */
      virtual ModelObsFixedStation& setDefaultObservable(const TypeID& type)
      { defaultObservable = type; return (*this); };


         /// Method to get a pointer to the default XvtStore<SatID> to be used
         /// with GNSS data structures.
      virtual XvtStore<SatID>* getDefaultEphemeris() const
      { return pDefaultEphemeris; };


         /** Method to set the default XvtStore<SatID> to be used with GNSS
          *  data structures.
          *
          * @param ephem     XvtStore<SatID> object to be used by default
          */
      virtual ModelObsFixedStation& setDefaultEphemeris(XvtStore<SatID>& ephem)
      { pDefaultEphemeris = &ephem; return (*this); };


         /// Either estimated or "a priori" position of receiver
      Position rxPos;


         /// Returns a string identifying this object.
      virtual std::string getClassName(void) const;


         /// Destructor.
      virtual ~ModelObsFixedStation() {};


   protected:


         /** Compute the modeled pseudoranges, given satellite ID's,
          *  pseudoranges and other data.
          *
          * @param Tr            Measured time of reception of the data.
          * @param Satellite     Vector of satellites.
          * @param Pseudorange   Vector of raw pseudoranges (parallel to
          *                      satellite), in meters.
          * @param Eph           EphemerisStore to be used.
          * @param pTropModel    Pointer to tropospheric model to be used.
          *                      By default points to NULL.
          * @param pIonoModel    Pointer to ionospheric model to be used.
          *                      By default points to NULL.
          *
          * @return
          *  Number of satellites with valid data
          *
          * @sa TropModel.hpp, IonoModelStore.hpp.
          */
      int Compute( const CommonTime& Tr,
                   Vector<SatID>& Satellite,
                   Vector<double>& Pseudorange,
                   const XvtStore<SatID>& Eph,
                   TropModel *pTropModel = NULL,
                   IonoModelStore *pIonoModel = NULL )
         throw(Exception);


         /// The elevation cut-off angle for accepted satellites.
         /// By default it is set to 10 degrees.
      double minElev;

         /// Boolean variable indicating if SV instrumental delays (TGD) will
         /// be included  in results. It is true by default.
      bool useTGD;

         /// Pointer to default ionospheric model.
      IonoModelStore *pDefaultIonoModel;

         /// Pointer to default tropospheric model.
      TropModel *pDefaultTropoModel;

         /// Default observable to be used when fed with GNSS data structures.
      TypeID defaultObservable;

         /// Pointer to default XvtStore<SatID> object when working with GNSS
         /// data structures.
      XvtStore<SatID>* pDefaultEphemeris;

         /// Initialization method
      virtual void InitializeValues()
      { setInitialRxPosition(); };


         /** Method to set the initial (a priori) position of receiver.
          * @return
          *  0 if OK
          *  -1 if problems arose
          */
      virtual int setInitialRxPosition( const double& aRx,
                                        const double& bRx,
                                        const double& cRx,
                           Position::CoordinateSystem s = Position::Cartesian,
                                        EllipsoidModel *ell = NULL,
                              ReferenceFrame frame = ReferenceFrame::Unknown );


         /// Method to set the initial (a priori) position of receiver.
      virtual int setInitialRxPosition(const Position& RxCoordinates);


         /// Method to set the initial (a priori) position of receiver.
      virtual int setInitialRxPosition();


         /// Method to get the tropospheric corrections.
      virtual double getTropoCorrections( TropModel *pTropModel,
                                          double elevation );


         /// Method to get the ionospheric corrections.
      virtual double getIonoCorrections( IonoModelStore *pIonoModel,
                                         CommonTime Tr,
                                         Position rxGeo,
                                         double elevation,
                                         double azimuth );


         /// Method to get TGD corrections.
      virtual double getTGDCorrections( CommonTime Tr,
                                        const XvtStore<SatID>& Eph,
                                        SatID sat );


   }; // End of class 'ModelObsFixedStation'

      //@}

}  // End of namespace gpstk

#endif   // GPSTK_MODELOBSFIXEDSTATION_HPP
