diff --git a/src/Radio/radio.cxx b/src/Radio/radio.cxx index 994f3aee9..4f2772e4e 100644 --- a/src/Radio/radio.cxx +++ b/src/Radio/radio.cxx @@ -23,8 +23,7 @@ #endif #include -#define NDEBUG -#include + #include #include #include "radio.hxx" @@ -37,15 +36,10 @@ FGRadioTransmission::FGRadioTransmission() { - /** radio parameters (which should probably be set for each radio) */ _receiver_sensitivity = -110.0; // typical AM receiver sensitivity seems to be 0.8 microVolt at 12dB SINAD /** AM transmitter power in dBm. - * Note this value is calculated from the typical final transistor stage output - * small aircraft have portable transmitters which operate at 36 dBm output (4 Watts) others operate in the range 10-20 W - * later possibly store this value in aircraft description - * ATC comms usually operate high power equipment, thus making the link asymetrical; this is taken care of in propagation routines * Typical output powers for ATC ground equipment, VHF-UHF: * 40 dBm - 10 W (ground, clearance) * 44 dBm - 20 W (tower) @@ -59,18 +53,14 @@ FGRadioTransmission::FGRadioTransmission() { _rx_antenna_height = 2.0; // RX antenna height above ground level - /** pilot plane's antenna gain + AI aircraft antenna gain - * real-life gain for conventional monopole/dipole antenna - **/ - _antenna_gain = 2.0; - _rx_antenna_gain = 1.0; + _rx_antenna_gain = 1.0; // gain expressed in dBi _tx_antenna_gain = 1.0; _rx_line_losses = 2.0; // to be configured for each station _tx_line_losses = 2.0; - _propagation_model = 2; // choose between models via option: realistic radio on/off + _propagation_model = 2; _terrain_sampling_distance = fgGetDouble("/sim/radio/sampling-distance", 90.0); // regular SRTM is 90 meters } @@ -124,10 +114,16 @@ double FGRadioTransmission::receiveNav(SGGeod tx_pos, double freq, int transmiss void FGRadioTransmission::receiveATC(SGGeod tx_pos, double freq, string text, int ground_to_air) { + if(ground_to_air == 1) { + _transmitter_power += 6.0; + _tx_antenna_height += 30.0; + _tx_antenna_gain += 3.0; + } + + double comm1 = getFrequency(1); double comm2 = getFrequency(2); if ( !(fabs(freq - comm1) <= 0.0001) && !(fabs(freq - comm2) <= 0.0001) ) { - //cerr << "Frequency not tuned: " << freq << " Radio1: " << comm1 << " Radio2: " << comm2 << endl; return; } else { @@ -139,13 +135,10 @@ void FGRadioTransmission::receiveATC(SGGeod tx_pos, double freq, string text, in // TODO: free space, round earth double signal = LOS_calculate_attenuation(tx_pos, freq, ground_to_air); if (signal <= 0.0) { - SG_LOG(SG_GENERAL, SG_BULK, "Signal below receiver minimum sensitivity: " << signal); - //cerr << "Signal below receiver minimum sensitivity: " << signal << endl; return; } else { - SG_LOG(SG_GENERAL, SG_BULK, "Signal completely readable: " << signal); - //cerr << "Signal completely readable: " << signal << endl; + fgSetString("/sim/messages/atc", text.c_str()); /** write signal strength above threshold to the property tree * to implement a simple S-meter just divide by 3 dB per grade (VHF norm) @@ -157,8 +150,6 @@ void FGRadioTransmission::receiveATC(SGGeod tx_pos, double freq, string text, in // Use ITM propagation model double signal = ITM_calculate_attenuation(tx_pos, freq, ground_to_air); if (signal <= 0.0) { - SG_LOG(SG_GENERAL, SG_BULK, "Signal below receiver minimum sensitivity: " << signal); - //cerr << "Signal below receiver minimum sensitivity: " << signal << endl; return; } if ((signal > 0.0) && (signal < 12.0)) { @@ -188,8 +179,6 @@ void FGRadioTransmission::receiveATC(SGGeod tx_pos, double freq, string text, in fgSetDouble("/sim/sound/voices/voice/volume", old_volume); } else { - SG_LOG(SG_GENERAL, SG_BULK, "Signal completely readable: " << signal); - //cerr << "Signal completely readable: " << signal << endl; fgSetString("/sim/messages/atc", text.c_str()); /** write signal strength above threshold to the property tree * to implement a simple S-meter just divide by 3 dB per grade (VHF norm) @@ -233,16 +222,11 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i double clutter_loss = 0.0; // loss due to vegetation and urban double tx_pow = _transmitter_power; - double ant_gain = _antenna_gain; + double ant_gain = _rx_antenna_gain + _tx_antenna_gain; double signal = 0.0; - if(transmission_type == 1) - tx_pow = _transmitter_power + 6.0; - - if((transmission_type == 1) || (transmission_type == 3)) - ant_gain = _antenna_gain + 3.0; //pilot plane's antenna gain + ground station antenna gain - double link_budget = tx_pow - _receiver_sensitivity + ant_gain; + double link_budget = tx_pow - _receiver_sensitivity - _rx_line_losses - _tx_line_losses + ant_gain; FGScenery * scenery = globals->get_scenery(); @@ -259,11 +243,7 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i SGGeoc center = SGGeoc::fromGeod( max_own_pos ); SGGeoc own_pos_c = SGGeoc::fromGeod( own_pos ); - /** position of sender radio antenna (HAAT) - sender can be aircraft or ground station - **/ - double ATC_HAAT = 30.0; - double Aircraft_HAAT = 5.0; + double sender_alt_ft,sender_alt; double transmitter_height=0.0; double receiver_height=0.0; @@ -302,7 +282,7 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i double elevation_under_pilot = 0.0; if (scenery->get_elevation_m( max_own_pos, elevation_under_pilot, NULL )) { - receiver_height = own_alt - elevation_under_pilot + 3; //assume antenna located 3 meters above ground + receiver_height = own_alt - elevation_under_pilot; } double elevation_under_sender = 0.0; @@ -313,10 +293,10 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i transmitter_height = sender_alt; } - if(transmission_type == 1) - transmitter_height += ATC_HAAT; - else - transmitter_height += Aircraft_HAAT; + + transmitter_height += _tx_antenna_height; + receiver_height += _rx_antenna_height; + SG_LOG(SG_GENERAL, SG_BULK, "ITM:: RX-height: " << receiver_height << " meters, TX-height: " << transmitter_height << " meters, Distance: " << distance_m << " meters"); @@ -383,7 +363,7 @@ double FGRadioTransmission::ITM_calculate_attenuation(SGGeod pos, double freq, i } double num_points= (double)_elevations.size(); - //cerr << "ITM:: Max alt between: " << max_alt_between << ", num points:" << num_points << endl; + _elevations.push_front(point_distance); _elevations.push_front(num_points -1); int size = _elevations.size(); @@ -442,7 +422,6 @@ void FGRadioTransmission::clutterLoss(double freq, double distance_m, double itm double grad = fabs(itm_elev[2] + transmitter_height - itm_elev[(int)itm_elev[0] + 2] + receiver_height) / distance_m; // First Fresnel radius double frs_rad = 548 * sqrt( (j * itm_elev[1] * (itm_elev[0] - j) * itm_elev[1] / 1000000) / ( distance_m * freq / 1000) ); - assert(frs_rad > 0); //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3 @@ -494,7 +473,6 @@ void FGRadioTransmission::clutterLoss(double freq, double distance_m, double itm double grad = fabs(itm_elev[2] + transmitter_height - itm_elev[num_points_1st + 2] + clutter_height) / distance_m; // First Fresnel radius double frs_rad = 548 * sqrt( (j * itm_elev[1] * (num_points_1st - j) * itm_elev[1] / 1000000) / ( num_points_1st * itm_elev[1] * freq / 1000) ); - assert(frs_rad > 0); //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3 @@ -539,7 +517,6 @@ void FGRadioTransmission::clutterLoss(double freq, double distance_m, double itm double grad = fabs(itm_elev[last+1] + clutter_height - itm_elev[(int)itm_elev[0] + 2] + receiver_height) / distance_m; // First Fresnel radius double frs_rad = 548 * sqrt( (j * itm_elev[1] * (num_points_2nd - j) * itm_elev[1] / 1000000) / ( num_points_2nd * itm_elev[1] * freq / 1000) ); - assert(frs_rad > 0); //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3 @@ -592,7 +569,6 @@ void FGRadioTransmission::clutterLoss(double freq, double distance_m, double itm double grad = fabs(itm_elev[2] + transmitter_height - itm_elev[num_points_1st + 2] + clutter_height) / distance_m; // First Fresnel radius double frs_rad = 548 * sqrt( (j * itm_elev[1] * (num_points_1st - j) * itm_elev[1] / 1000000) / ( num_points_1st * itm_elev[1] * freq / 1000) ); - assert(frs_rad > 0); //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3 @@ -637,7 +613,6 @@ void FGRadioTransmission::clutterLoss(double freq, double distance_m, double itm // First Fresnel radius double frs_rad = 548 * sqrt( (j * itm_elev[1] * (num_points_2nd - j) * itm_elev[1] / 1000000) / ( num_points_2nd * itm_elev[1] * freq / 1000) ); - assert(frs_rad > 0); //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3 double min_elev = SGMiscd::min(itm_elev[last+1] + clutter_height, itm_elev[num_points_1st + num_points_2nd +2] + clutter_height); @@ -682,7 +657,6 @@ void FGRadioTransmission::clutterLoss(double freq, double distance_m, double itm // First Fresnel radius double frs_rad = 548 * sqrt( (j * itm_elev[1] * (num_points_3rd - j) * itm_elev[1] / 1000000) / ( num_points_3rd * itm_elev[1] * freq / 1000) ); - assert(frs_rad > 0); //double earth_h = distance_m * (distance_m - j * itm_elev[1]) / ( 1000000 * 12.75 * 1.33 ); // K=4/3 @@ -847,10 +821,9 @@ double FGRadioTransmission::LOS_calculate_attenuation(SGGeod pos, double freq, i frq_mhz = freq; double dbloss; double tx_pow = _transmitter_power; - double ant_gain = _antenna_gain; + double ant_gain = _rx_antenna_gain + _tx_antenna_gain; double signal = 0.0; - double ATC_HAAT = 30.0; - double Aircraft_HAAT = 5.0; + double sender_alt_ft,sender_alt; double transmitter_height=0.0; double receiver_height=0.0; @@ -859,13 +832,8 @@ double FGRadioTransmission::LOS_calculate_attenuation(SGGeod pos, double freq, i double own_alt_ft = fgGetDouble("/position/altitude-ft"); double own_alt= own_alt_ft * SG_FEET_TO_METER; - if(transmission_type == 1) - tx_pow = _transmitter_power + 6.0; - - if((transmission_type == 1) || (transmission_type == 3)) - ant_gain = _antenna_gain + 3.0; //pilot plane's antenna gain + ground station antenna gain - double link_budget = tx_pow - _receiver_sensitivity + ant_gain; + double link_budget = tx_pow - _receiver_sensitivity - _rx_line_losses - _tx_line_losses + ant_gain; //cerr << "ITM:: pilot Lat: " << own_lat << ", Lon: " << own_lon << ", Alt: " << own_alt << endl; @@ -881,10 +849,10 @@ double FGRadioTransmission::LOS_calculate_attenuation(SGGeod pos, double freq, i double distance_m = SGGeodesy::distanceM(own_pos, sender_pos); - if(transmission_type == 1) - transmitter_height += ATC_HAAT; - else - transmitter_height += Aircraft_HAAT; + + transmitter_height += _tx_antenna_height; + receiver_height += _rx_antenna_height; + /** radio horizon calculation with wave bending k=4/3 */ double receiver_horizon = 4.12 * sqrt(receiver_height); diff --git a/src/Radio/radio.hxx b/src/Radio/radio.hxx index 4c2bb7f64..1261b7c51 100644 --- a/src/Radio/radio.hxx +++ b/src/Radio/radio.hxx @@ -44,7 +44,6 @@ private: double _transmitter_power; double _tx_antenna_height; double _rx_antenna_height; - double _antenna_gain; double _rx_antenna_gain; double _tx_antenna_gain; double _rx_line_losses; @@ -72,6 +71,10 @@ public: void setRxSensitivity(double sensitivity) { _receiver_sensitivity = sensitivity; }; void setTxAntennaHeight(double tx_antenna_height) { _tx_antenna_height = tx_antenna_height; }; void setRxAntennaHeight(double rx_antenna_height) { _rx_antenna_height = rx_antenna_height; }; + void setTxAntennaGain(double tx_antenna_gain) { _tx_antenna_gain = tx_antenna_gain; }; + void setRxAntennaGain(double rx_antenna_gain) { _rx_antenna_gain = rx_antenna_gain; }; + void setTxLineLosses(double tx_line_losses) { _tx_line_losses = tx_line_losses; }; + void setRxLineLosses(double rx_line_losses) { _rx_line_losses = rx_line_losses; }; void setPropagationModel(int model) { _propagation_model = model; }; // transmission_type: 0 for air to ground 1 for ground to air, 2 for air to air, 3 for pilot to ground, 4 for pilot to air void receiveATC(SGGeod tx_pos, double freq, string text, int transmission_type);