1 // tacan.cxx - Tactical Navigation Beacon.
2 // Written by Vivian Meazaa, started 2005.
4 // This file is in the Public Domain and comes with no warranty.
10 #include <simgear/compiler.h>
11 #include <simgear/math/sg_geodesy.hxx>
12 #include <simgear/math/sg_random.h>
14 #include <Main/fg_props.hxx>
15 #include <Navaids/navlist.hxx>
26 * Start by calculating the radar horizon based on the elevation
27 * difference, then clamp to the maximum, then add a fudge for
28 * borderline reception.
31 adjust_range (double transmitter_elevation_ft, double aircraft_altitude_ft,
35 double delta_elevation_ft =
36 fabs(aircraft_altitude_ft - transmitter_elevation_ft);
37 double range_nm = 1.23 * sqrt(delta_elevation_ft);
38 if (range_nm > max_range_nm)
39 range_nm = max_range_nm;
40 else if (range_nm < 20.0)
42 double rand = sg_random();
43 SG_LOG( SG_INSTR, SG_DEBUG, " tacan range " << range_nm << " max range " << max_range_nm);
44 return range_nm + (range_nm * rand * rand);
48 TACAN::TACAN ( SGPropertyNode *node )
49 : _last_distance_nm(0),
50 _last_frequency_mhz(-1),
51 _time_before_search_sec(0),
53 _transmitter_valid(false),
54 _transmitter_elevation_ft(0),
55 _transmitter_range_nm(0),
56 _transmitter_bias(0.0),
63 for ( i = 0; i < node->nChildren(); ++i ) {
64 SGPropertyNode *child = node->getChild(i);
65 string cname = child->getName();
66 string cval = child->getStringValue();
67 if ( cname == "name" ) {
69 } else if ( cname == "number" ) {
70 num = child->getIntValue();
72 SG_LOG( SG_INSTR, SG_DEBUG, "Error in TACAN config logic" );
73 if ( name.length() ) {
74 SG_LOG( SG_INSTR, SG_DEBUG, "Section = " << name );
81 : _last_distance_nm(0),
82 _last_frequency_mhz(-1),
83 _time_before_search_sec(0),
85 _transmitter_valid(false),
86 _transmitter_elevation_ft(0),
87 _transmitter_range_nm(0),
88 _transmitter_bearing_deg(0),
89 _transmitter_bias(0.0),
90 _transmitter_name(""),
103 branch = "/instrumentation/" + name;
105 SGPropertyNode *node = fgGetNode(branch.c_str(), num, true );
107 _longitude_node = fgGetNode("/position/longitude-deg", true);
108 _latitude_node = fgGetNode("/position/latitude-deg", true);
109 _altitude_node = fgGetNode("/position/altitude-ft", true);
110 _heading_node = fgGetNode("/orientation/heading-deg", true);
111 _yaw_node = fgGetNode("/orientation/side-slip-deg", true);
112 _serviceable_node = node->getChild("serviceable", 0, true);
113 _electrical_node = fgGetNode("/systems/electrical/outputs/tacan", true);
114 _ident_node = node->getChild("ident", 0, true);
115 SGPropertyNode *fnode = node->getChild("frequencies", 0, true);
116 _source_node = fnode->getChild("source", 0, true);
117 _frequency_node = fnode->getChild("selected-mhz", 0, true);
118 _channel_node = fnode->getChild("selected-channel", 1, true);
119 _channel_node = fnode->getChild("selected-channel", 2, true);
120 _channel_node = fnode->getChild("selected-channel", 3, true);
121 _channel_node = fnode->getChild("selected-channel", 4, true);
122 _in_range_node = node->getChild("in-range", 0, true);
123 _distance_node = node->getChild("indicated-distance-nm", 0, true);
124 _speed_node = node->getChild("indicated-ground-speed-kt", 0, true);
125 _time_node = node->getChild("indicated-time-min", 0, true);
126 _name_node = node->getChild("name", 0, true);
127 _bearing_node = node->getChild("indicated-bearing-true-deg", 0, true);
128 SGPropertyNode *dnode = node->getChild("display", 0, true);
129 _x_shift_node = dnode->getChild("x-shift", 0, true);
130 _y_shift_node = dnode->getChild("y-shift", 0, true);
131 _rotation_node = dnode->getChild("rotation", 0, true);
132 _channel_node = dnode->getChild("channel", 0, true);
134 SGPropertyNode *cnode = fgGetNode("/ai/models/carrier", num, false );
136 _carrier_name_node = cnode->getChild("name", 0, false);
138 SGPropertyNode *tnode = fgGetNode("/ai/models/aircraft", num, false);
140 _tanker_callsign_node = tnode->getChild("callsign", 0, false);
142 SGPropertyNode *mnode = fgGetNode("/ai/models/multiplayer", num, false);
144 _mp_callsign_node = mnode->getChild("callsign", 0, false);
148 TACAN::update (double delta_time_sec)
153 double mobile_az2 = 0;
154 double mobile_bearing = 0;
155 double mobile_distance = 0;
156 double frequency_mhz = 0;
158 string _channel, _last_channel, _channel_1, _channel_2,_channel_3, _channel_4;
160 // If it's off, don't waste any time.
161 if (!_serviceable_node->getBoolValue() || !_electrical_node->getBoolValue()) {
162 _last_distance_nm = 0;
163 _in_range_node->setBoolValue(false);
164 _distance_node->setDoubleValue(0);
165 _speed_node->setDoubleValue(0);
166 _time_node->setDoubleValue(0);
167 SG_LOG( SG_INSTR, SG_DEBUG, "skip tacan" );
171 // Figure out the source
172 const char * source = _source_node->getStringValue();
174 if (source[0] == '\0') {
176 branch = "/instrumentation/" + name + "/frequencies/selected-channel";
177 _source_node->setStringValue(branch.c_str());
178 source = _source_node->getStringValue();
179 SG_LOG( SG_INSTR, SG_DEBUG, "source " << source );
182 _channel_1 = fgGetString("/instrumentation/tacan/frequencies/selected-channel[1]");
183 _channel_2 = fgGetString("/instrumentation/tacan/frequencies/selected-channel[2]");
184 _channel_3 = fgGetString("/instrumentation/tacan/frequencies/selected-channel[3]");
185 _channel_4 = fgGetString("/instrumentation/tacan/frequencies/selected-channel[4]");
187 SG_LOG( SG_INSTR, SG_DEBUG, "channels " << _channel_1 << _channel_2 << _channel_3 << _channel_4);
189 _channel = _channel_1 + _channel_2 + _channel_3 + _channel_4;
192 if (_channel != _last_channel) {
193 _time_before_search_sec = 0;
194 _last_channel = _channel;
195 frequency_mhz = searchChannel(_channel);
196 SG_LOG( SG_INSTR, SG_DEBUG, "frequency " << frequency_mhz );
197 _frequency_node->setDoubleValue(frequency_mhz);
200 SG_LOG( SG_INSTR, SG_DEBUG, "channel " << _channel );
201 // Get the aircraft position
202 double longitude_deg = _longitude_node->getDoubleValue();
203 double latitude_deg = _latitude_node->getDoubleValue();
204 double altitude_m = _altitude_node->getDoubleValue() * SG_FEET_TO_METER;
205 double heading = _heading_node->getDoubleValue() ;
206 double yaw = _yaw_node->getDoubleValue() ;
207 double longitude_rad = longitude_deg * SGD_DEGREES_TO_RADIANS;
208 double latitude_rad = latitude_deg * SGD_DEGREES_TO_RADIANS;
210 // On timeout, scan again
211 _time_before_search_sec -= delta_time_sec;
212 if (_time_before_search_sec < 0 && frequency_mhz >= 0)
213 search(frequency_mhz, longitude_rad, latitude_rad, altitude_m);
215 // Calculate the distance to the transmitter
217 //calculate the bearing and range of the mobile from the aircraft
218 SG_LOG( SG_INSTR, SG_DEBUG, "carrier_lat " << _mobile_lat);
219 SG_LOG( SG_INSTR, SG_DEBUG, "carrier_lon " << _mobile_lon);
220 SG_LOG( SG_INSTR, SG_DEBUG, "carrier_name " << _mobile_name);
221 SG_LOG( SG_INSTR, SG_DEBUG, "carrier_valid " << _mobile_valid);
222 geo_inverse_wgs_84(altitude_m,
227 &mobile_bearing, &mobile_az2, &mobile_distance);
229 //calculate the bearing and range of the station from the aircraft
230 geo_inverse_wgs_84(altitude_m,
235 &bearing, &az2, &distance);
239 if ( mobile_distance <= distance && _mobile_valid) {
240 SG_LOG( SG_INSTR, SG_DEBUG, "mobile_distance_m " << mobile_distance);
241 SG_LOG( SG_INSTR, SG_DEBUG, "distance_m " << distance);
242 bearing = mobile_bearing;
243 distance = mobile_distance;
244 _transmitter_elevation_ft = _mobile_elevation_ft;
245 _transmitter_range_nm = _mobile_range_nm;
246 _transmitter_bias = _mobile_bias;
247 _transmitter_name = _mobile_name;
248 _name_node->setStringValue(_transmitter_name.c_str());
249 _transmitter_ident = _mobile_ident;
250 _ident_node->setStringValue(_transmitter_ident.c_str());
251 _channel_node->setStringValue(_channel.c_str());
254 //// calculate some values for boresight display
255 double distance_nm = distance * SG_METER_TO_NM;
257 //// calculate look left/right to target, without yaw correction
258 // double horiz_offset = bearing - heading;
260 // if (horiz_offset > 180.0) horiz_offset -= 360.0;
261 // if (horiz_offset < -180.0) horiz_offset += 360.0;
263 //// now correct look left/right for yaw
264 // horiz_offset += yaw;
266 // use the bearing for a plan position indicator display
268 double horiz_offset = bearing;
270 SG_LOG( SG_INSTR, SG_DEBUG, "distance_nm " << distance_nm << " bearing "
271 << bearing << " horiz_offset " << horiz_offset);
273 // calculate values for radar display
274 double y_shift = distance_nm * cos( horiz_offset * SG_DEGREES_TO_RADIANS);
275 double x_shift = distance_nm * sin( horiz_offset * SG_DEGREES_TO_RADIANS);
277 SG_LOG( SG_INSTR, SG_DEBUG, "y_shift " << y_shift << " x_shift " << x_shift);
282 sgGeodToCart(Point3D(longitude_rad, latitude_rad, altitude_m));
283 double distance_nm = _transmitter.distance3D(location) * SG_METER_TO_NM;*/
285 double range_nm = adjust_range(_transmitter_elevation_ft,
286 altitude_m * SG_METER_TO_FEET,
287 _transmitter_range_nm);
289 if (distance_nm <= range_nm) {
290 double speed_kt = (fabs(distance_nm - _last_distance_nm) *
291 ((1 / delta_time_sec) * 3600.0));
292 _last_distance_nm = distance_nm;
294 _in_range_node->setBoolValue(true);
295 double tmp_dist = distance_nm - _transmitter_bias;
296 if ( tmp_dist < 0.0 ) {
299 _distance_node->setDoubleValue( tmp_dist );
300 _speed_node->setDoubleValue(speed_kt);
301 _time_node->setDoubleValue(distance_nm/speed_kt*60.0);
302 _bearing_node->setDoubleValue(bearing);
303 _x_shift_node->setDoubleValue(x_shift);
304 _y_shift_node->setDoubleValue(y_shift);
305 _rotation_node->setDoubleValue(rotation);
307 _last_distance_nm = 0;
308 _in_range_node->setBoolValue(false);
309 _distance_node->setDoubleValue(0);
310 _speed_node->setDoubleValue(0);
311 _time_node->setDoubleValue(0);
312 _bearing_node->setDoubleValue(0);
313 _x_shift_node->setDoubleValue(0);
314 _y_shift_node->setDoubleValue(0);
315 _rotation_node->setDoubleValue(0);
318 // If we can't find a valid station set everything to zero
319 if (!_transmitter_valid && !_mobile_valid ) {
320 _in_range_node->setBoolValue(false);
321 _distance_node->setDoubleValue(0);
322 _speed_node->setDoubleValue(0);
323 _time_node->setDoubleValue(0);
324 _bearing_node->setDoubleValue(0);
325 _x_shift_node->setDoubleValue(0);
326 _y_shift_node->setDoubleValue(0);
327 _rotation_node->setDoubleValue(0);
328 _transmitter_name = "";
329 _name_node->setStringValue(_transmitter_name.c_str());
330 _transmitter_ident = "";
331 _ident_node->setStringValue(_transmitter_ident.c_str());
332 _channel_node->setStringValue(_channel.c_str());
335 } // end function update
338 TACAN::search (double frequency_mhz, double longitude_rad,
339 double latitude_rad, double altitude_m)
342 bool freq_valid = false;
344 SG_LOG( SG_INSTR, SG_DEBUG, "tacan freq " << frequency_mhz );
347 _time_before_search_sec = 1.0;
349 //try any carriers first
350 FGNavRecord *mobile_tacan
351 = globals->get_carrierlist()->findStationByFreq( frequency_mhz );
352 freq_valid = (mobile_tacan != NULL);
353 SG_LOG( SG_INSTR, SG_DEBUG, "mobile freqency valid " << freq_valid );
357 string str1( mobile_tacan->get_name() );
359 SGPropertyNode * branch = fgGetNode("ai/models", true);
360 vector<SGPropertyNode_ptr> carrier = branch->getChildren("carrier");
362 number = carrier.size();
364 SG_LOG( SG_INSTR, SG_DEBUG, "carrier " << number );
366 for ( i = 0; i < number; ++i ) {
367 string str2 ( carrier[i]->getStringValue("name", ""));
368 SG_LOG( SG_INSTR, SG_DEBUG, "carrier name " << str2 );
370 SG_LOG( SG_INSTR, SG_DEBUG, "strings 1 " << str1 << " 2 " << str2 );
371 unsigned int loc1= str1.find( str2, 0 );
372 if ( loc1 != string::npos && str2 != "" ) {
373 SG_LOG( SG_INSTR, SG_DEBUG, " string found" );
374 _mobile_lat = carrier[i]->getDoubleValue("position/latitude-deg");
375 _mobile_lon = carrier[i]->getDoubleValue("position/longitude-deg");
376 _mobile_elevation_ft = mobile_tacan->get_elev_ft();
377 _mobile_range_nm = mobile_tacan->get_range();
378 _mobile_bias = mobile_tacan->get_multiuse();
379 _mobile_name = mobile_tacan->get_name();
380 _mobile_ident = mobile_tacan->get_trans_ident();
381 _mobile_valid = true;
382 SG_LOG( SG_INSTR, SG_DEBUG, " carrier transmitter valid " << _mobile_valid );
385 _mobile_valid = false;
386 SG_LOG( SG_INSTR, SG_DEBUG, " carrier transmitter invalid " << _mobile_valid );
390 SG_LOG( SG_INSTR, SG_DEBUG, "name " << _mobile_name);
391 SG_LOG( SG_INSTR, SG_DEBUG, "lat " << _mobile_lat << "lon " << _mobile_lon);
392 SG_LOG( SG_INSTR, SG_DEBUG, "elev " << _mobile_elevation_ft);
394 //try any AI tankers second
396 if ( !_mobile_valid) {
397 SG_LOG( SG_INSTR, SG_DEBUG, "tanker transmitter valid start " << _mobile_valid );
399 SGPropertyNode * branch = fgGetNode("ai/models", true);
400 vector<SGPropertyNode_ptr> tanker = branch->getChildren("aircraft");
402 number = tanker.size();
404 SG_LOG( SG_INSTR, SG_DEBUG, "tanker number " << number );
406 for ( i = 0; i < number; ++i ) {
407 string str4 ( tanker[i]->getStringValue("callsign", ""));
408 SG_LOG( SG_INSTR, SG_DEBUG, "tanker callsign " << str4 );
410 SG_LOG( SG_INSTR, SG_DEBUG, "strings 1 " << str1 << " 4 " << str4 );
411 unsigned int loc1= str1.find( str4, 0 );
412 if ( loc1 != string::npos && str4 != "" ) {
413 SG_LOG( SG_INSTR, SG_DEBUG, " string found" );
414 _mobile_lat = tanker[i]->getDoubleValue("position/latitude-deg");
415 _mobile_lon = tanker[i]->getDoubleValue("position/longitude-deg");
416 _mobile_elevation_ft = tanker[i]->getDoubleValue("position/altitude-ft");
417 _mobile_range_nm = mobile_tacan->get_range();
418 _mobile_bias = mobile_tacan->get_multiuse();
419 _mobile_name = mobile_tacan->get_name();
420 _mobile_ident = mobile_tacan->get_trans_ident();
421 _mobile_valid = true;
422 SG_LOG( SG_INSTR, SG_DEBUG, " tanker transmitter valid " << _mobile_valid );
425 _mobile_valid = false;
426 SG_LOG( SG_INSTR, SG_DEBUG, " tanker transmitter invalid " << _mobile_valid );
430 SG_LOG( SG_INSTR, SG_DEBUG, "tanker name " << _mobile_name);
431 SG_LOG( SG_INSTR, SG_DEBUG, "lat " << _mobile_lat << "lon " << _mobile_lon);
432 SG_LOG( SG_INSTR, SG_DEBUG, "elev " << _mobile_elevation_ft);
433 SG_LOG( SG_INSTR, SG_DEBUG, "range " << _mobile_range_nm);
436 //try any mp tankers third, if we haven't found the tanker in the ai aircraft
438 if ( !_mobile_valid ) {
439 SG_LOG( SG_INSTR, SG_DEBUG, " mp tanker transmitter valid start " << _mobile_valid );
441 SGPropertyNode * branch = fgGetNode("ai/models", true);
442 vector<SGPropertyNode_ptr> mp_tanker = branch->getChildren("multiplayer");
444 number = mp_tanker.size();
446 SG_LOG( SG_INSTR, SG_DEBUG, " mp tanker number " << number );
448 for ( i = 0; i < number; ++i ) {
449 string str6 ( mp_tanker[i]->getStringValue("callsign", ""));
450 SG_LOG( SG_INSTR, SG_DEBUG, "mp tanker callsign " << str6 );
452 SG_LOG( SG_INSTR, SG_DEBUG, "strings 1 " << str1 << " 5 " << str6 );
453 unsigned int loc1= str1.find( str6, 0 );
454 if ( loc1 != string::npos && str6 != "" ) {
455 SG_LOG( SG_INSTR, SG_DEBUG, " string found" );
456 _mobile_lat = mp_tanker[i]->getDoubleValue("position/latitude-deg");
457 _mobile_lon = mp_tanker[i]->getDoubleValue("position/longitude-deg");
458 _mobile_elevation_ft = mp_tanker[i]->getDoubleValue("position/altitude-ft");
459 _mobile_range_nm = mobile_tacan->get_range();
460 _mobile_bias = mobile_tacan->get_multiuse();
461 _mobile_name = mobile_tacan->get_name();
462 _mobile_ident = mobile_tacan->get_trans_ident();
463 _mobile_valid = true;
465 SG_LOG( SG_INSTR, SG_DEBUG, " mp tanker transmitter valid " << _mobile_valid );
466 SG_LOG( SG_INSTR, SG_DEBUG, " mp_tanker name " << _mobile_name);
467 SG_LOG( SG_INSTR, SG_DEBUG, " mp lat " << _mobile_lat << "lon " << _mobile_lon);
468 SG_LOG( SG_INSTR, SG_DEBUG, " mp elev " << _mobile_elevation_ft);
469 SG_LOG( SG_INSTR, SG_DEBUG, " mp range " << _mobile_range_nm);
472 _mobile_valid = false;
473 SG_LOG( SG_INSTR, SG_DEBUG, " mp tanker transmitter invalid " << _mobile_valid );
478 _mobile_valid = false;
479 SG_LOG( SG_INSTR, SG_DEBUG, " mobile transmitter invalid " << _mobile_valid );
482 // try the TACAN/VORTAC list next
484 = globals->get_tacanlist()->findByFreq( frequency_mhz, longitude_rad,
485 latitude_rad, altitude_m);
487 _transmitter_valid = (tacan != NULL);
489 if ( _transmitter_valid ) {
490 SG_LOG( SG_INSTR, SG_DEBUG, "transmitter valid " << _transmitter_valid );
492 _transmitter_lat = tacan->get_lat();
493 _transmitter_lon = tacan->get_lon();
494 _transmitter_elevation_ft = tacan->get_elev_ft();
495 _transmitter_range_nm = tacan->get_range();
496 _transmitter_bias = tacan->get_multiuse();
497 _transmitter_name = tacan->get_name();
498 _name_node->setStringValue(_transmitter_name.c_str());
499 _transmitter_ident = tacan->get_trans_ident();
500 _ident_node->setStringValue(_transmitter_ident.c_str());
502 SG_LOG( SG_INSTR, SG_DEBUG, "name " << _transmitter_name);
503 SG_LOG( SG_INSTR, SG_DEBUG, "lat " << _transmitter_lat << "lon " << _transmitter_lon);
504 SG_LOG( SG_INSTR, SG_DEBUG, "elev " << _transmitter_elevation_ft);
507 SG_LOG( SG_INSTR, SG_DEBUG, "transmitter invalid " << _transmitter_valid );
512 TACAN::searchChannel (const string& _channel){
514 double frequency_khz = 0;
517 = globals->get_channellist()->findByChannel( _channel );
518 double _freq_valid = (freq != NULL);
519 SG_LOG( SG_INSTR, SG_DEBUG, "freq valid " << _freq_valid );
521 frequency_khz = freq->get_freq();
522 SG_LOG( SG_INSTR, SG_DEBUG, "freq output " << frequency_khz );
524 if (frequency_khz >=9620 && frequency_khz <= 12130)
525 return frequency_khz/100;
527 return frequency_khz = 0;
528 } // end TACAN::searchChannel