SVNumXRef.hpp

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//==============================================================================
//
//  This file is part of GNSSTk, the ARL:UT GNSS Toolkit.
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//  This software was developed by Applied Research Laboratories at the
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/*   SVNumXRef.hpp
*
*   Applied Research Laboratories, The University of Texas at Austin
*   June 2007
*
*   This class implements a cross-reference between PRN numbers and NAVSTAR IDs.
*   Since PRN numbers are re-used (historically, there's a limit of 1-32 in
*   the PRN IDs) it's necessary provide a several->one PRN ID ->NAVSTAR mapping.
*   Originally, the NAVSTAR->PRN ID mapping is unique. However, this is no longer
*   true and several -> one mapping now necessary in both directions.
*
*   As a result, the cross reference methods support the ability to provide a
*   date so the method can select between multiple options.
*
*   Note: Thie information is not contained anywhere in the navigation message.
*   Therefore, it needs to come from "outside the system".  The information
*   contained in the class constructor will also need to updated with each
*   new launch and disposal.  This is a sore point, but there appears to be
*   no easy way around it.
*
*   Note: The data in the module is derived from several sources and there
*   are some issues of interpretation.
*    - The USNO website ftp://tycho.usno.navy.mil/pub/gps/gpsb2.txt contains
*      a very helpful history
*    - This class only attempts to track the relationship between PRN ID and
*      NAVSTAR numbers.  There's no guarantee a SV was operationally, broadcasting,
*      or healthy.
*
*  MEMBER METHODS
*     SVNumXRef( ); - Constructor.  Works from a fixed table that is compiled
*                     into the code.
*     int getNAVSTAR( const int PRNID, const gnsstk::CommonTime dt ) const; -
*                     Given a PRNID and a date, return the NAVSTAR number
*                     related to thsat PRNID at the date provided.  May
*                     throw "NoNAVSTARNumFound" error. The date defaults to
*                     the current date if one is not provided.
*     int getPRNID( const int NAVSTARID, const gnsstk::CommonTime dt ) const; -
*                     Given a NAVSTAR Number and a date, return the corresponding
*                     PRNID related to the NAVSTAR Number on the specified date.
*                     May throw "No PRNNumberFound" error." The date defaults to
*                     the current date if one is not provided.
*
*  The following four members parallel the preceding four and provide a
*  means of determining is the specified information is available prior to
*  making a "get" call.  This is useful if you want to avoid writing
*  "try/catch" blocks.
*     bool PRNIDavailable( const int NAVSTARID, const gnsstk::CommonTime dt ) const;
*     bool NAVSTARIDAvailable( const int PRNID, const gnsstk::CommonTime dt ) const;
*
*
*     bool NAVSTARIDActive( const int NAVSTARID, const gnsstk::CommonTime dt ) const; -
*     Given a NAVSTAR ID and a date, return true if the specified NAVSTAR ID was
*     active on the date provided. The date defaults to the current date if one
*     is not provided.
*
*/
#ifndef SVNUMXREF_HPP
#define SVNUMXREF_HPP
 
#include <map>
#include <utility>
 
#include "CommonTime.hpp"
#include "SystemTime.hpp"
#include "gps_constants.hpp"
#include "Exception.hpp"
#include "TimeRange.hpp"
 
 
namespace gnsstk
{
 
  NEW_EXCEPTION_CLASS( NoPRNNumberFound, gnsstk::Exception);
  NEW_EXCEPTION_CLASS( NoNAVSTARNumberFound, gnsstk::Exception);
 
 
  class XRefNode
  {
     public:
       XRefNode( const int NumArg,
                     const gnsstk::TimeRange tr );
       XRefNode( const int NumArg,
                     const gnsstk::CommonTime begDT,
                     const gnsstk::CommonTime endDT );
       int getNAVSTARNum() const;
       int getPRNNum() const;
       gnsstk::CommonTime getBeginTime() const;
       gnsstk::CommonTime getEndTime() const;
       gnsstk::TimeRange getTimeRange() const;
       bool isApplicable( gnsstk::CommonTime dt ) const;
       std::string toString() const;
 
     protected:
        int Num;
        gnsstk::TimeRange valid;
  };
 
    typedef std::multimap<int, XRefNode>::const_iterator SVNumXRefListCI;
    typedef std::pair<SVNumXRefListCI,SVNumXRefListCI> SVNumXRefPair;
    typedef std::multimap<int, XRefNode>::const_iterator NAVNumXRefCI;
    typedef std::pair<NAVNumXRefCI,NAVNumXRefCI> NAVNumXRefPair;
 
  class SVNumXRef
  {
     public:
 
      enum BlockType
      {
        I,
        II,
        IIA,
        IIR,
        IIR_M,
        IIF,
  III
      };
      SVNumXRef( );
      ~SVNumXRef() {}
      BlockType getBlockType( const int NAVSTARID ) const;
      std::string getBlockTypeString( const int NAVSTARID ) const;
      int getNAVSTAR( const int PRNID, const gnsstk::CommonTime dt ) const;
      int getPRNID( const int NAVSTARID, const gnsstk::CommonTime dt ) const;
      bool PRNIDAvailable( const int NAVSTARID, const gnsstk::CommonTime dt ) const;
      bool NAVSTARIDAvailable( const int PRNID, const gnsstk::CommonTime dt ) const;
      bool BlockTypeAvailable( const int NAVSTARID ) const;
      bool NAVSTARIDActive( const int NAVSTARID, const gnsstk::CommonTime dt ) const;
      void dump(std::ostream& out=std::cout) const;
      bool isConsistent() const;
 
      const std::multimap<int, XRefNode>& getPtoNMap()
        { return PtoNMap; }
 
      protected:
         std::multimap<int,XRefNode> NtoPMap;
         std::multimap<int,XRefNode> PtoNMap;
         std::map<int,BlockType> NtoBMap;
  };
 
    inline int XRefNode::getNAVSTARNum() const { return(Num); }
    inline int XRefNode::getPRNNum() const { return(Num); }
    inline gnsstk::CommonTime XRefNode::getBeginTime() const { return( valid.getStart() ); }
    inline gnsstk::CommonTime XRefNode::getEndTime() const { return( valid.getEnd() ); }
    inline gnsstk::TimeRange XRefNode::getTimeRange() const { return( valid ); }
 
 
  }
#endif