Expose a radio function (receiveBeacon) to the Nasal subsystem

[flightgear.git] / src / Radio / radio.cxx

diff --git a/src/Radio/radio.cxx b/src/Radio/radio.cxx
index dec08ea0fdcdff5fe2386999a6bb1a38c403c4a3..3412a151b3fd48f1f5f6b7839073580200d13d0a 100644 (file)
--- a/src/Radio/radio.cxx
+++ b/src/Radio/radio.cxx
@@ -37,7 +37,7 @@
 FGRadioTransmission::FGRadioTransmission() {
        
        
-       _receiver_sensitivity = -110.0; // typical AM receiver sensitivity seems to be 0.8 microVolt at 12dB SINAD
+       _receiver_sensitivity = -105.0; // typical AM receiver sensitivity seems to be 0.8 microVolt at 12dB SINAD
        
        /** AM transmitter power in dBm.
        *       Typical output powers for ATC ground equipment, VHF-UHF:
@@ -115,6 +115,28 @@ double FGRadioTransmission::receiveNav(SGGeod tx_pos, double freq, int transmiss
 
 }
 
+double FGRadioTransmission::receiveBeacon(double lat, double lon, double elev, double heading, double pitch) {
+       
+       
+       _transmitter_power = 36;
+       _tx_antenna_height += 0.0;
+       _tx_antenna_gain += 0.5; 
+       elev = elev * SG_FEET_TO_METER;
+       double freq = _root_node->getDoubleValue("station[0]/frequency", 118.0);
+       int ground_to_air = 1;
+       string text = "Beacon1";
+       double comm1 = getFrequency(1);
+       double comm2 = getFrequency(2);
+       if ( !(fabs(freq - comm1) <= 0.0001) &&  !(fabs(freq - comm2) <= 0.0001) ) {
+               return -1;
+       }
+       SGGeod tx_pos = SGGeod::fromDegM( lon, lat, elev );
+       double signal = ITM_calculate_attenuation(tx_pos, freq, ground_to_air);
+       
+       return signal;
+}
+
+
 /*** Receive ATC radio communication as text
 ***/
 void FGRadioTransmission::receiveATC(SGGeod tx_pos, double freq, string text, int ground_to_air) {
@@ -236,7 +258,7 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
        double own_alt= own_alt_ft * SG_FEET_TO_METER;
        
        
-       //cerr << "ITM:: pilot Lat: " << own_lat << ", Lon: " << own_lon << ", Alt: " << own_alt << endl;
+       
        
        SGGeod own_pos = SGGeod::fromDegM( own_lon, own_lat, own_alt );
        SGGeod max_own_pos = SGGeod::fromDegM( own_lon, own_lat, SG_MAX_ELEVATION_M );
@@ -253,7 +275,7 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
        sender_alt = sender_alt_ft * SG_FEET_TO_METER;
        SGGeod max_sender_pos = SGGeod::fromGeodM( pos, SG_MAX_ELEVATION_M );
        SGGeoc sender_pos_c = SGGeoc::fromGeod( sender_pos );
-       //cerr << "ITM:: sender Lat: " << parent->getLatitude() << ", Lon: " << parent->getLongitude() << ", Alt: " << sender_alt << endl;
+       
        
        double point_distance= _terrain_sampling_distance; 
        double course = SGGeodesy::courseRad(own_pos_c, sender_pos_c);
@@ -361,29 +383,34 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
        
        double num_points= (double)elevations.size();
 
+
        elevations.push_front(point_distance);
        elevations.push_front(num_points -1);
+
        int size = elevations.size();
-       double itm_elev[size];
+       double *itm_elev;
+       itm_elev = new double[size];
+
        for(int i=0;i<size;i++) {
                itm_elev[i]=elevations[i];
-               //cerr << "ITM:: itm_elev: " << elevations[i] << endl;
-       }
+               
 
+       }
+       
        if((transmission_type == 3) || (transmission_type == 4)) {
                // the sender and receiver roles are switched
                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( _root_node->getBoolValue( "use-clutter-attenuation", false ) )
-                       clutterLoss(frq_mhz, itm_elev, materials, receiver_height, transmitter_height, p_mode, horizons, clutter_loss);
+                       calculate_clutter_loss(frq_mhz, 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( _root_node->getBoolValue( "use-clutter-attenuation", false ) )
-                       clutterLoss(frq_mhz, itm_elev, materials, transmitter_height, receiver_height, p_mode, horizons, clutter_loss);
+                       calculate_clutter_loss(frq_mhz, itm_elev, materials, transmitter_height, receiver_height, p_mode, horizons, clutter_loss);
        }
        
        double pol_loss = 0.0;
@@ -430,8 +457,12 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
        _root_node->setDoubleValue("station[0]/field-strength-uV", field_strength_uV);
        _root_node->setDoubleValue("station[0]/signal", signal);
        _root_node->setDoubleValue("station[0]/tx-erp", tx_erp);
+
        //_root_node->setDoubleValue("station[0]/tx-pattern-gain", tx_pattern_gain);
        //_root_node->setDoubleValue("station[0]/rx-pattern-gain", rx_pattern_gain);
+
+       delete[] itm_elev;
+
        return signal;
 
 }
@@ -440,7 +471,7 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i
 *       We are only worried about clutter loss, terrain influence 
 *       on the first Fresnel zone is calculated in the ITM functions
 ***/
-void FGRadioTransmission::clutterLoss(double freq, double itm_elev[], deque<string> materials,
+void FGRadioTransmission::calculate_clutter_loss(double freq, double itm_elev[], deque<string> &materials,
        double transmitter_height, double receiver_height, int p_mode,
        double horizons[], double &clutter_loss) {
        
@@ -947,7 +978,7 @@ double FGRadioTransmission::watt_to_dbm(double power_watt) {
 }
 
 double FGRadioTransmission::dbm_to_watt(double dbm) {
-       return exp( (dbm-30) * log(10) / 10);   // returns Watts
+       return exp( (dbm-30) * log(10.0) / 10.0);       // returns Watts
 }
 
 double FGRadioTransmission::dbm_to_microvolt(double dbm) {