src/Instrumentation/dme.hxx

   1 // dme.hxx - distance-measuring equipment.
   2 // Written by David Megginson, started 2003.
   3 //
   4 // This file is in the Public Domain and comes with no warranty.
   5
   6
   7 #ifndef __INSTRUMENTS_DME_HXX
   8 #define __INSTRUMENTS_DME_HXX 1
   9
  10 #ifndef __cplusplus
  11 # error This library requires C++
  12 #endif
  13
  14 #include <simgear/math/point3d.hxx>
  15 #include <simgear/props/props.hxx>
  16
  17 #include <Main/fgfs.hxx>
  18
  19
  20 /**
  21  * Model a DME radio.
  22  *
  23  * Input properties:
  24  *
  25  * /position/longitude-deg
  26  * /position/latitude-deg
  27  * /position/altitude-ft
  28  * /systems/electrical/outputs/dme
  29  * /instrumentation/dme/serviceable
  30  * /instrumentation/dme/frequencies/source
  31  * /instrumentation/dme/frequencies/selected-mhz
  32  *
  33  * Output properties:
  34  *
  35  * /instrumentation/dme/in-range
  36  * /instrumentation/dme/indicated-distance-nm
  37  * /instrumentation/dme/indicated-ground-speed-kt
  38  * /instrumentation/dme/indicated-time-kt
  39  */
  40 class DME : public FGSubsystem
  41 {
  42
  43 public:
  44
  45     DME ();
  46     virtual ~DME ();
  47
  48     virtual void init ();
  49     virtual void update (double delta_time_sec);
  50
  51 private:
  52
  53     void search (double frequency, double longitude_rad,
  54                  double latitude_rad, double altitude_m);
  55
  56     SGPropertyNode_ptr _longitude_node;
  57     SGPropertyNode_ptr _latitude_node;
  58     SGPropertyNode_ptr _altitude_node;
  59     SGPropertyNode_ptr _serviceable_node;
  60     SGPropertyNode_ptr _electrical_node;
  61     SGPropertyNode_ptr _source_node;
  62     SGPropertyNode_ptr _frequency_node;
  63
  64     SGPropertyNode_ptr _in_range_node;
  65     SGPropertyNode_ptr _distance_node;
  66     SGPropertyNode_ptr _speed_node;
  67     SGPropertyNode_ptr _time_node;
  68
  69     double _last_distance_nm;
  70     double _last_frequency_mhz;
  71     double _time_before_search_sec;
  72
  73     bool _transmitter_valid;
  74     Point3D _transmitter;
  75     double _transmitter_elevation_ft;
  76     double _transmitter_range_nm;
  77
  78 };
  79
  80
  81 #endif // __INSTRUMENTS_DME_HXX