Set a couple of properties using the node /sim/radio

Also use correct the polarization calculations, using
Simgear constants for degree to radians conversions

diff --git a/src/Radio/antenna.cxx b/src/Radio/antenna.cxx
index 22496d81e9b7b5ab589ea403a430e8f8202e8b7c..dc6983723cb4315ea44165c1efb633d7470d5bde 100644 (file)
--- a/src/Radio/antenna.cxx
+++ b/src/Radio/antenna.cxx
@@ -33,19 +33,22 @@ FGRadioAntenna::FGRadioAntenna() {
        
        _mirror_y = 1;
        _mirror_z = 1;
+       _invert_ground = 0;
 }
 
 FGRadioAntenna::~FGRadioAntenna() {
        
 }
 
-double FGRadioAntenna::calculate_gain(double azimuth, double theta) {
+double FGRadioAntenna::calculate_gain(double azimuth, double elevation) {
        return 0;
 }
 
 
 
-
+/*** load external plot file generated by NEC4
+*
+***/
 void FGRadioAntenna::_load_antenna_pattern() {
        
 }

diff --git a/src/Radio/antenna.hxx b/src/Radio/antenna.hxx
index ec5d302533d9a000a04029a06f9b095cf3524af4..f24c133ee2d8131f10dc8327c1293aff12f4273e 100644 (file)
--- a/src/Radio/antenna.hxx
+++ b/src/Radio/antenna.hxx
@@ -33,10 +33,12 @@ private:
        void _load_antenna_pattern();
        int _mirror_y;
        int _mirror_z;
-       double _heading;
+       int _invert_ground;
+       double _heading_deg;
+       double _elevation_angle_deg;
        struct AntennaGain {
                double azimuth;
-               double elevation_angle;
+               double elevation;
                double gain;
        };
        
@@ -47,7 +49,7 @@ public:
        
        FGRadioAntenna();
     ~FGRadioAntenna();
-       double calculate_gain(double azimuth, double theta);
+       double calculate_gain(double azimuth, double elevation);
        
        
 };

diff --git a/src/Radio/radio.cxx b/src/Radio/radio.cxx
index d5211615a427fabae29981783dd8d6aa1547d2a5..9f21a936edec25350ff2b6773480032991c36306 100644 (file)
--- a/src/Radio/radio.cxx
+++ b/src/Radio/radio.cxx
@@ -63,7 +63,9 @@ FGRadioTransmission::FGRadioTransmission() {
        _polarization = 1; // default vertical
        
        _propagation_model = 2; 
-       _terrain_sampling_distance = fgGetDouble("/sim/radio/sampling-distance", 90.0); // regular SRTM is 90 meters
+       
+       _root_node = fgGetNode("sim/radio", true);
+       _terrain_sampling_distance = _root_node->getDoubleValue("sampling-distance", 90.0); // regular SRTM is 90 meters
 }
 
 FGRadioTransmission::~FGRadioTransmission() 
@@ -145,7 +147,7 @@ void FGRadioTransmission::receiveATC(SGGeod tx_pos, double freq, string text, in
                                /** write signal strength above threshold to the property tree
                                *       to implement a simple S-meter just divide by 3 dB per grade (VHF norm)
                                **/
-                               fgSetDouble("/sim/radio/comm1-signal", signal);
+                               _root_node->setDoubleValue("station[0]/signal", signal);
                        }
                }
                else if ( _propagation_model == 2 ) {
@@ -177,7 +179,7 @@ void FGRadioTransmission::receiveATC(SGGeod tx_pos, double freq, string text, in
                                //cerr << "Usable signal at limit: " << signal << endl;
                                fgSetDouble("/sim/sound/voices/voice/volume", volume);
                                fgSetString("/sim/messages/atc", text.c_str());
-                               fgSetDouble("/sim/radio/comm1-signal", signal);
+                               _root_node->setDoubleValue("station[0]/signal", signal);
                                fgSetDouble("/sim/sound/voices/voice/volume", old_volume);
                        }
                        else {
@@ -185,7 +187,7 @@ void FGRadioTransmission::receiveATC(SGGeod tx_pos, double freq, string text, in
                                /** write signal strength above threshold to the property tree
                                *       to implement a simple S-meter just divide by 3 dB per grade (VHF norm)
                                **/
-                               fgSetDouble("/sim/radio/comm1-signal", signal);
+                               _root_node->setDoubleValue("station[0]/signal", signal);
                        }
                        
                }
@@ -302,7 +304,10 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
        
        SG_LOG(SG_GENERAL, SG_BULK,
                        "ITM:: RX-height: " << receiver_height << " meters, TX-height: " << transmitter_height << " meters, Distance: " << distance_m << " meters");
-       cerr << "ITM:: RX-height: " << receiver_height << " meters, TX-height: " << transmitter_height << " meters, Distance: " << distance_m << " meters" << endl;
+       //cerr << "ITM:: RX-height: " << receiver_height << " meters, TX-height: " << transmitter_height << " meters, Distance: " << distance_m << " meters" << endl;
+       _root_node->setDoubleValue("station[0]/rx-height", receiver_height);
+       _root_node->setDoubleValue("station[0]/tx-height", transmitter_height);
+       _root_node->setDoubleValue("station[0]/distance", distance_m);
        
        unsigned int e_size = (deque<unsigned>::size_type)max_points;
        
@@ -373,24 +378,33 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
                point_to_point(itm_elev, receiver_height, transmitter_height,
                        eps_dielect, sgm_conductivity, eno, frq_mhz, radio_climate,
                        pol, conf, rel, dbloss, strmode, p_mode, horizons, errnum);
-               if( fgGetBool( "/sim/radio/use-clutter-attenuation", false ) )
+               if( _root_node->getBoolValue( "use-clutter-attenuation", false ) )
                        clutterLoss(frq_mhz, distance_m, itm_elev, materials, receiver_height, transmitter_height, p_mode, horizons, clutter_loss);
        }
        else {
                point_to_point(itm_elev, transmitter_height, receiver_height,
                        eps_dielect, sgm_conductivity, eno, frq_mhz, radio_climate,
                        pol, conf, rel, dbloss, strmode, p_mode, horizons, errnum);
-               if( fgGetBool( "/sim/radio/use-clutter-attenuation", false ) )
+               if( _root_node->getBoolValue( "use-clutter-attenuation", false ) )
                        clutterLoss(frq_mhz, distance_m, itm_elev, materials, transmitter_height, receiver_height, p_mode, horizons, clutter_loss);
        }
+       
+       double pol_loss = 0.0;
+       if (_polarization == 1) {
+               pol_loss = polarization_loss();
+       }
        SG_LOG(SG_GENERAL, SG_BULK,
                        "ITM:: Link budget: " << link_budget << ", Attenuation: " << dbloss << " dBm, " << strmode << ", Error: " << errnum);
-       cerr << "ITM:: Link budget: " << link_budget << ", Attenuation: " << dbloss << " dBm, " << strmode << ", Error: " << errnum << endl;
-       
-       cerr << "Clutter loss: " << clutter_loss << endl;
+       //cerr << "ITM:: Link budget: " << link_budget << ", Attenuation: " << dbloss << " dBm, " << strmode << ", Error: " << errnum << endl;
+       _root_node->setDoubleValue("station[0]/link-budget", link_budget);
+       _root_node->setDoubleValue("station[0]/terrain-attenuation", dbloss);
+       _root_node->setStringValue("station[0]/prop-mode", strmode);
+       _root_node->setDoubleValue("station[0]/clutter-attenuation", clutter_loss);
+       _root_node->setDoubleValue("station[0]/polarization-attenuation", pol_loss);
+       //cerr << "Clutter loss: " << clutter_loss << endl;
        //if (errnum == 4)      // if parameters are outside sane values for lrprop, the alternative method is used
        //      return -1;
-       signal = link_budget - dbloss - clutter_loss;
+       signal = link_budget - dbloss - clutter_loss + pol_loss;
        return signal;
 
 }
@@ -876,15 +890,25 @@ double FGRadioTransmission::polarization_loss() {
        
        double theta_deg;
        double roll = fgGetDouble("/orientation/roll-deg");
+       if (fabs(roll) > 85.0)
+               roll = 85.0;
        double pitch = fgGetDouble("/orientation/pitch-deg");
-       double theta = acos( sqrt( cos(roll) * cos(roll) + cos(pitch) * cos(pitch) ));
-       if (_polarization == 1)
+       if (fabs(pitch) > 85.0)
+               pitch = 85.0;
+       double theta = fabs( atan( sqrt( 
+               pow(tan(roll * SGD_DEGREES_TO_RADIANS), 2) + 
+               pow(tan(pitch * SGD_DEGREES_TO_RADIANS), 2) )) * SGD_RADIANS_TO_DEGREES);
+       
+       if (_polarization == 0)
                theta_deg = 90.0 - theta;
        else
                theta_deg = theta;
-       if (fabs(theta_deg) > 85.0)     // we don't want to converge into infinity
+       if (theta_deg > 85.0)   // we don't want to converge into infinity
                theta_deg = 85.0;
-       return 10 * log10(cos(theta_deg) * cos(theta_deg));
+       
+       double loss = 10 * log10( pow(cos(theta_deg * SGD_DEGREES_TO_RADIANS), 2) );
+       //cerr << "Polarization loss: " << loss << " dBm " << endl;
+       return loss;
 }
 
 

diff --git a/src/Radio/radio.hxx b/src/Radio/radio.hxx
index cafa2b3866b73997bbe46795429f49e0860166f5..92ce66fbc58197892d32d4a9c15dddeec3dd80bd 100644 (file)
--- a/src/Radio/radio.hxx
+++ b/src/Radio/radio.hxx
@@ -51,7 +51,7 @@ private:
        double _terrain_sampling_distance;
        int _polarization;
        std::map<string, double[2]> _mat_database;
-       
+       SGPropertyNode *_root_node;
        int _propagation_model; /// 0 none, 1 round Earth, 2 ITM
        double polarization_loss();
        double ITM_calculate_attenuation(SGGeod tx_pos, double freq, int ground_to_air);