TropModel.hpp

Go to the documentation of this file.

//==============================================================================
//
//  This file is part of GNSSTk, the ARL:UT GNSS Toolkit.
//
//  The GNSSTk is free software; you can redistribute it and/or modify
//  it under the terms of the GNU Lesser General Public License as published
//  by the Free Software Foundation; either version 3.0 of the License, or
//  any later version.
//
//  The GNSSTk is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with GNSSTk; if not, write to the Free Software Foundation,
//  Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
//
//  This software was developed by Applied Research Laboratories at the
//  University of Texas at Austin.
//  Copyright 2004-2022, The Board of Regents of The University of Texas System
//
//==============================================================================
 
//==============================================================================
//
//  This software was 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.
//
//  Pursuant to DoD Directive 523024
//
//  DISTRIBUTION STATEMENT A: This software has been approved for public
//                            release, distribution is unlimited.
//
//==============================================================================
 
#ifndef TROP_MODEL_HPP
#define TROP_MODEL_HPP
 
#include "Exception.hpp"
#include "ObsEpochMap.hpp"
#include "WxObsMap.hpp"
#include "Xvt.hpp"
#include "Position.hpp"
#include "Matrix.hpp"
#include "GNSSconstants.hpp"
#include "gnsstk_export.h"
 
#define THROW_IF_INVALID() {if (!valid) {InvalidTropModel e("Invalid model");GNSSTK_THROW(e);}}
 
// Model of the troposphere, used to compute non-dispersive delay of
// satellite signal as function of satellite elevation as seen at the
// receiver. Both wet and hydrostatic (dry) components are computed.
//
// The default model (implemented here) is a simple Black model.
//
// In this model (and many others), the wet and hydrostatic (dry) components are
// independent, the zenith delays depend only on the weather
// (temperature, pressure and humidity), and the mapping functions
// depend only on the elevation of the satellite as seen at the
// receiver. In general, this is not true; other models depend on,
// for example, latitude or day of year.
//
// Other models may be implemented by inheriting this class and
// redefining the virtual functions, and (perhaps) adding other
// 'set...()' routines as needed.
 
namespace gnsstk
{
 
 
   NEW_EXCEPTION_CLASS(InvalidTropModel, gnsstk::Exception);
 
   class TropModel
   {
   public:
      GNSSTK_EXPORT static const double CELSIUS_TO_KELVIN;
 
      virtual ~TropModel() {}
 
      bool isValid()
      { return valid; }
 
      virtual std::string name()
      { return std::string("Undefined"); }
 
      virtual double correction(double elevation) const;
 
      virtual double correction(const Position& RX,
                                const Position& SV,
                                const CommonTime& tt);
 
      virtual double correction(const Xvt& RX,
                                const Xvt& SV,
                                const CommonTime& tt)
      { Position R(RX),S(SV);  return TropModel::correction(R,S,tt); }
 
      virtual double dry_zenith_delay() const = 0;
 
      virtual double wet_zenith_delay() const = 0;
 
      virtual double dry_mapping_function(double elevation)
         const = 0;
 
      virtual double wet_mapping_function(double elevation)
         const = 0;
 
      virtual void setWeather(const double& T,
                              const double& P,
                              const double& H);
 
      virtual void setWeather(const WxObservation& wx);
 
      virtual void setReceiverHeight(const double& ht) {}
 
      virtual void setReceiverLatitude(const double& lat) {}
 
      virtual void setReceiverLongitude(const double& lon) {}
 
      virtual void setDayOfYear(const int& d) {}
 
      double SaasDryDelay(const double pr, const double lat, const double ht)
         const
      {
         return (0.0022768*pr/(1-0.00266*::cos(2*lat*DEG_TO_RAD)-0.00028*ht/1000.));
      }
 
      static void weatherByStandardAtmosphereModel(
         const double& ht, double& T, double& P, double& H);
 
   protected:
      bool valid;           
      double temp;          
      double press;         
      double humid;         
 
   }; // end class TropModel
 
 
      //---------------------------------------------------------------------------------
   class ZeroTropModel : public TropModel
   {
   public:
      virtual std::string name()
      { return std::string("Zero"); }
 
      virtual double correction(double elevation) const
      { return 0.0; }
 
      virtual double correction(const Position& RX,
                                const Position& SV,
                                const CommonTime& tt)
      { return 0.0; }
 
      virtual double correction(const Xvt& RX,
                                const Xvt& SV,
                                const CommonTime& tt)
      { return 0.0; }
 
      virtual double dry_zenith_delay() const
      { return 0.0; }
 
      virtual double wet_zenith_delay() const
      { return 0.0; }
 
      virtual double dry_mapping_function(double elevation) const
      { return 0.0; }
 
      virtual double wet_mapping_function(double elevation) const
      { return 0.0; }
 
   }; // end class ZeroTropModel
 
}
#endif