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 #include <simgear/props/props.hxx>
  11 #include <simgear/structure/subsystem_mgr.hxx>
  12
  13
  14 /**
  15  * Model a DME radio.
  16  *
  17  * Input properties:
  18  *
  19  * /position/longitude-deg
  20  * /position/latitude-deg
  21  * /position/altitude-ft
  22  * /systems/electrical/outputs/dme
  23  * /instrumentation/"name"/serviceable
  24  * /instrumentation/"name"/frequencies/source
  25  * /instrumentation/"name"/frequencies/selected-mhz
  26  *
  27  * Output properties:
  28  *
  29  * /instrumentation/"name"/in-range
  30  * /instrumentation/"name"/indicated-distance-nm
  31  * /instrumentation/"name"/indicated-ground-speed-kt
  32  * /instrumentation/"name"/indicated-time-kt
  33  */
  34 class DME : public SGSubsystem
  35 {
  36
  37 public:
  38
  39     DME ( SGPropertyNode *node );
  40     virtual ~DME ();
  41
  42     virtual void init ();
  43     virtual void update (double delta_time_sec);
  44
  45 private:
  46
  47     void search (double frequency, double longitude_rad,
  48                  double latitude_rad, double altitude_m);
  49
  50     SGPropertyNode_ptr _longitude_node;
  51     SGPropertyNode_ptr _latitude_node;
  52     SGPropertyNode_ptr _altitude_node;
  53     SGPropertyNode_ptr _serviceable_node;
  54     SGPropertyNode_ptr _electrical_node;
  55     SGPropertyNode_ptr _source_node;
  56     SGPropertyNode_ptr _frequency_node;
  57
  58     SGPropertyNode_ptr _in_range_node;
  59     SGPropertyNode_ptr _distance_node;
  60     SGPropertyNode_ptr _speed_node;
  61     SGPropertyNode_ptr _time_node;
  62
  63     double _last_distance_nm;
  64     double _last_frequency_mhz;
  65     double _time_before_search_sec;
  66
  67     bool _transmitter_valid;
  68     SGVec3d _transmitter;
  69     double _transmitter_elevation_ft;
  70     double _transmitter_range_nm;
  71     double _transmitter_bias;
  72
  73     string _name;
  74     int _num;
  75
  76 };
  77
  78
  79 #endif // __INSTRUMENTS_DME_HXX