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

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Also use correct the polarization calculations, using
Simgear constants for degree to radians conversions
This commit is contained in:
adrian 2011-12-02 17:38:52 +02:00
parent e3e23b0915
commit 6179c26a04
4 changed files with 50 additions and 21 deletions
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7
src/Radio/antenna.cxx
View file

@ -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() {
}

8
src/Radio/antenna.hxx
View file

@ -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);
};

54
src/Radio/radio.cxx
View file

@ -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;
}

2
src/Radio/radio.hxx
View file

@ -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);