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 #include <simgear/structure/subsystem_mgr.hxx>
  17
  18
  19 /**
  20  * Model a DME radio.
  21  *
  22  * Input properties:
  23  *
  24  * /position/longitude-deg
  25  * /position/latitude-deg
  26  * /position/altitude-ft
  27  * /systems/electrical/outputs/dme
  28  * /instrumentation/dme/serviceable
  29  * /instrumentation/dme/frequencies/source
  30  * /instrumentation/dme/frequencies/selected-mhz
  31  *
  32  * Output properties:
  33  *
  34  * /instrumentation/dme/in-range
  35  * /instrumentation/dme/indicated-distance-nm
  36  * /instrumentation/dme/indicated-ground-speed-kt
  37  * /instrumentation/dme/indicated-time-kt
  38  */
  39 class DME : public SGSubsystem
  40 {
  41
  42 public:
  43
  44     DME ();
  45     virtual ~DME ();
  46
  47     virtual void init ();
  48     virtual void update (double delta_time_sec);
  49
  50 private:
  51
  52     void search (double frequency, double longitude_rad,
  53                  double latitude_rad, double altitude_m);
  54
  55     SGPropertyNode_ptr _longitude_node;
  56     SGPropertyNode_ptr _latitude_node;
  57     SGPropertyNode_ptr _altitude_node;
  58     SGPropertyNode_ptr _serviceable_node;
  59     SGPropertyNode_ptr _electrical_node;
  60     SGPropertyNode_ptr _source_node;
  61     SGPropertyNode_ptr _frequency_node;
  62
  63     SGPropertyNode_ptr _in_range_node;
  64     SGPropertyNode_ptr _distance_node;
  65     SGPropertyNode_ptr _speed_node;
  66     SGPropertyNode_ptr _time_node;
  67
  68     double _last_distance_nm;
  69     double _last_frequency_mhz;
  70     double _time_before_search_sec;
  71
  72     bool _transmitter_valid;
  73     Point3D _transmitter;
  74     double _transmitter_elevation_ft;
  75     double _transmitter_range_nm;
  76
  77 };
  78
  79
  80 #endif // __INSTRUMENTS_DME_HXX