1 // gps.cxx - distance-measuring equipment.
2 // Written by David Megginson, started 2003.
4 // This file is in the Public Domain and comes with no warranty.
10 #include <simgear/compiler.h>
11 #include <Aircraft/aircraft.hxx>
13 #include <simgear/route/route.hxx>
14 #include <simgear/math/sg_random.h>
15 #include <simgear/sg_inlines.h>
16 #include <Airports/simple.hxx>
18 #include <Main/fg_init.hxx>
19 #include <Main/globals.hxx>
20 #include <Main/fg_props.hxx>
21 #include <Main/util.hxx>
22 #include <Navaids/fixlist.hxx>
23 #include <Navaids/navlist.hxx>
30 GPS::GPS ( SGPropertyNode *node)
32 _last_longitude_deg(0),
33 _last_latitude_deg(0),
37 _wp0_longitude_deg(0),
40 _wp1_longitude_deg(0),
47 for ( i = 0; i < node->nChildren(); ++i ) {
48 SGPropertyNode *child = node->getChild(i);
49 string cname = child->getName();
50 string cval = child->getStringValue();
51 if ( cname == "name" ) {
53 } else if ( cname == "number" ) {
54 num = child->getIntValue();
56 SG_LOG( SG_INSTR, SG_WARN, "Error in gps config logic" );
57 if ( name.length() ) {
58 SG_LOG( SG_INSTR, SG_WARN, "Section = " << name );
66 _last_longitude_deg(0),
67 _last_latitude_deg(0),
71 _wp0_longitude_deg(0),
74 _wp1_longitude_deg(0),
93 branch = "/instrumentation/" + name;
95 SGPropertyNode *node = fgGetNode(branch.c_str(), num, true );
97 _longitude_node = fgGetNode("/position/longitude-deg", true);
98 _latitude_node = fgGetNode("/position/latitude-deg", true);
99 _altitude_node = fgGetNode("/position/altitude-ft", true);
100 _magvar_node = fgGetNode("/environment/magnetic-variation-deg", true);
101 _serviceable_node = node->getChild("serviceable", 0, true);
102 _electrical_node = fgGetNode("/systems/electrical/outputs/gps", true);
104 SGPropertyNode *wp_node = node->getChild("wp", 0, true);
105 SGPropertyNode *wp0_node = wp_node->getChild("wp", 0, true);
106 SGPropertyNode *wp1_node = wp_node->getChild("wp", 1, true);
107 addWp = wp1_node->getChild("Add-to-route", 0, true);
109 _wp0_longitude_node = wp0_node->getChild("longitude-deg", 0, true);
110 _wp0_latitude_node = wp0_node->getChild("latitude-deg", 0, true);
111 _wp0_altitude_node = wp0_node->getChild("altitude-ft", 0, true);
112 _wp0_ID_node = wp0_node->getChild("ID", 0, true);
113 _wp0_name_node = wp0_node->getChild("name", 0, true);
114 _wp0_course_node = wp0_node->getChild("desired-course-deg", 0, true);
115 _wp0_waypoint_type_node = wp0_node->getChild("waypoint-type", 0, true);
116 _wp0_distance_node = wp0_node->getChild("distance-nm", 0, true);
117 _wp0_ttw_node = wp0_node->getChild("TTW", 0, true);
118 _wp0_bearing_node = wp0_node->getChild("bearing-true-deg", 0, true);
119 _wp0_mag_bearing_node = wp0_node->getChild("bearing-mag-deg", 0, true);
120 _wp0_course_deviation_node =
121 wp0_node->getChild("course-deviation-deg", 0, true);
122 _wp0_course_error_nm_node = wp0_node->getChild("course-error-nm", 0, true);
123 _wp0_to_flag_node = wp0_node->getChild("to-flag", 0, true);
124 _true_wp0_bearing_error_node =
125 wp0_node->getChild("true-bearing-error-deg", 0, true);
126 _magnetic_wp0_bearing_error_node =
127 wp0_node->getChild("magnetic-bearing-error-deg", 0, true);
129 _wp1_longitude_node = wp1_node->getChild("longitude-deg", 0, true);
130 _wp1_latitude_node = wp1_node->getChild("latitude-deg", 0, true);
131 _wp1_altitude_node = wp1_node->getChild("altitude-ft", 0, true);
132 _wp1_ID_node = wp1_node->getChild("ID", 0, true);
133 _wp1_name_node = wp1_node->getChild("name", 0, true);
134 _wp1_course_node = wp1_node->getChild("desired-course-deg", 0, true);
135 _wp1_waypoint_type_node = wp1_node->getChild("waypoint-type", 0, true);
136 _wp1_distance_node = wp1_node->getChild("distance-nm", 0, true);
137 _wp1_ttw_node = wp1_node->getChild("TTW", 0, true);
138 _wp1_bearing_node = wp1_node->getChild("bearing-true-deg", 0, true);
139 _wp1_mag_bearing_node = wp1_node->getChild("bearing-mag-deg", 0, true);
140 _wp1_course_deviation_node =
141 wp1_node->getChild("course-deviation-deg", 0, true);
142 _wp1_course_error_nm_node = wp1_node->getChild("course-error-nm", 0, true);
143 _wp1_to_flag_node = wp1_node->getChild("to-flag", 0, true);
144 _true_wp1_bearing_error_node =
145 wp1_node->getChild("true-bearing-error-deg", 0, true);
146 _magnetic_wp1_bearing_error_node =
147 wp1_node->getChild("magnetic-bearing-error-deg", 0, true);
148 _get_nearest_airport_node =
149 wp1_node->getChild("get-nearest-airport", 0, true);
151 _tracking_bug_node = node->getChild("tracking-bug", 0, true);
152 _raim_node = node->getChild("raim", 0, true);
154 _indicated_longitude_node =
155 node->getChild("indicated-longitude-deg", 0, true);
156 _indicated_latitude_node =
157 node->getChild("indicated-latitude-deg", 0, true);
158 _indicated_altitude_node =
159 node->getChild("indicated-altitude-ft", 0, true);
160 _indicated_vertical_speed_node =
161 node->getChild("indicated-vertical-speed", 0, true);
163 node->getChild("indicated-track-true-deg", 0, true);
164 _magnetic_track_node =
165 node->getChild("indicated-track-magnetic-deg", 0, true);
167 node->getChild("indicated-ground-speed-kt", 0, true);
169 node->getChild("odometer", 0, true);
170 _trip_odometer_node =
171 node->getChild("trip-odometer", 0, true);
172 _true_bug_error_node =
173 node->getChild("true-bug-error-deg", 0, true);
174 _magnetic_bug_error_node =
175 node->getChild("magnetic-bug-error-deg", 0, true);
178 wp_node->getChild("leg-distance-nm", 0, true);
180 wp_node->getChild("leg-true-course-deg", 0, true);
181 _leg_magnetic_course_node =
182 wp_node->getChild("leg-mag-course-deg", 0, true);
183 _alt_dist_ratio_node =
184 wp_node->getChild("alt-dist-ratio", 0, true);
185 _leg_course_deviation_node =
186 wp_node->getChild("leg-course-deviation-deg", 0, true);
187 _leg_course_error_nm_node =
188 wp_node->getChild("leg-course-error-nm", 0, true);
190 wp_node->getChild("leg-to-flag", 0, true);
191 _alt_deviation_node =
192 wp_node->getChild("alt-deviation-ft", 0, true);
194 _route = node->getChild("route", 0, true);
195 popWp = _route->getChild("Pop-WP", 0, true);
197 addWp->setBoolValue(false);
198 popWp->setBoolValue(false);
200 _serviceable_node->setBoolValue(true);
204 GPS::update (double delta_time_sec)
206 // If it's off, don't bother.
207 if (!_serviceable_node->getBoolValue() ||
208 !_electrical_node->getBoolValue()) {
210 _last_longitude_deg = 0;
211 _last_latitude_deg = 0;
212 _last_altitude_m = 0;
214 _raim_node->setDoubleValue(false);
215 _indicated_longitude_node->setDoubleValue(0);
216 _indicated_latitude_node->setDoubleValue(0);
217 _indicated_altitude_node->setDoubleValue(0);
218 _indicated_vertical_speed_node->setDoubleValue(0);
219 _true_track_node->setDoubleValue(0);
220 _magnetic_track_node->setDoubleValue(0);
221 _speed_node->setDoubleValue(0);
222 _wp1_distance_node->setDoubleValue(0);
223 _wp1_bearing_node->setDoubleValue(0);
224 _wp1_longitude_node->setDoubleValue(0);
225 _wp1_latitude_node->setDoubleValue(0);
226 _wp1_course_node->setDoubleValue(0);
227 _odometer_node->setDoubleValue(0);
228 _trip_odometer_node->setDoubleValue(0);
229 _tracking_bug_node->setDoubleValue(0);
230 _true_bug_error_node->setDoubleValue(0);
231 _magnetic_bug_error_node->setDoubleValue(0);
232 _true_wp1_bearing_error_node->setDoubleValue(0);
233 _magnetic_wp1_bearing_error_node->setDoubleValue(0);
237 // Get the aircraft position
238 // TODO: Add noise and other errors.
239 double longitude_deg = _longitude_node->getDoubleValue();
240 double latitude_deg = _latitude_node->getDoubleValue();
241 double altitude_m = _altitude_node->getDoubleValue() * SG_FEET_TO_METER;
242 double magvar_deg = _magvar_node->getDoubleValue();
246 // Bias and random error
247 double random_factor = sg_random();
248 double random_error = 1.4;
249 double error_radius = 5.1;
250 double bias_max_radius = 5.1;
251 double random_max_radius = 1.4;
253 bias_length += (random_factor-0.5) * 1.0e-3;
254 if (bias_length <= 0.0) bias_length = 0.0;
255 else if (bias_length >= bias_max_radius) bias_length = bias_max_radius;
256 bias_angle += (random_factor-0.5) * 1.0e-3;
257 if (bias_angle <= 0.0) bias_angle = 0.0;
258 else if (bias_angle >= 360.0) bias_angle = 360.0;
260 double random_length = random_factor * random_max_radius;
261 double random_angle = random_factor * 360.0;
263 double bias_x = bias_length * cos(bias_angle * SG_PI / 180.0);
264 double bias_y = bias_length * sin(bias_angle * SG_PI / 180.0);
265 double random_x = random_length * cos(random_angle * SG_PI / 180.0);
266 double random_y = random_length * sin(random_angle * SG_PI / 180.0);
267 double error_x = bias_x + random_x;
268 double error_y = bias_y + random_y;
269 double error_length = sqrt(error_x*error_x + error_y*error_y);
270 double error_angle = atan(error_y / error_x) * 180.0 / SG_PI;
275 geo_direct_wgs_84 ( altitude_m, latitude_deg,
276 longitude_deg, error_angle,
277 error_length, &lat2, &lon2,
279 //cout << lat2 << " " << lon2 << endl;
280 printf("%f %f \n", bias_length, bias_angle);
281 printf("%3.7f %3.7f \n", lat2, lon2);
282 printf("%f %f \n", error_length, error_angle);
288 double speed_kt, vertical_speed_mpm;
290 _raim_node->setBoolValue(true);
291 _indicated_longitude_node->setDoubleValue(longitude_deg);
292 _indicated_latitude_node->setDoubleValue(latitude_deg);
293 _indicated_altitude_node->setDoubleValue(altitude_m * SG_METER_TO_FEET);
296 double track1_deg, track2_deg, distance_m, odometer, mag_track_bearing;
297 geo_inverse_wgs_84(altitude_m,
298 _last_latitude_deg, _last_longitude_deg,
299 latitude_deg, longitude_deg,
300 &track1_deg, &track2_deg, &distance_m);
301 speed_kt = ((distance_m * SG_METER_TO_NM) *
302 ((1 / delta_time_sec) * 3600.0));
303 vertical_speed_mpm = ((altitude_m - _last_altitude_m) * 60 /
305 _indicated_vertical_speed_node->setDoubleValue
306 (vertical_speed_mpm * SG_METER_TO_FEET);
307 _true_track_node->setDoubleValue(track1_deg);
308 mag_track_bearing = track1_deg - magvar_deg;
309 SG_NORMALIZE_RANGE(mag_track_bearing, 0.0, 360.0);
310 _magnetic_track_node->setDoubleValue(mag_track_bearing);
311 speed_kt = fgGetLowPass(_last_speed_kts, speed_kt, delta_time_sec/20.0);
312 _last_speed_kts = speed_kt;
313 _speed_node->setDoubleValue(speed_kt);
315 odometer = _odometer_node->getDoubleValue();
316 _odometer_node->setDoubleValue(odometer + distance_m * SG_METER_TO_NM);
317 odometer = _trip_odometer_node->getDoubleValue();
318 _trip_odometer_node->setDoubleValue(odometer + distance_m * SG_METER_TO_NM);
320 // Get waypoint 0 position
321 double wp0_longitude_deg = _wp0_longitude_node->getDoubleValue();
322 double wp0_latitude_deg = _wp0_latitude_node->getDoubleValue();
323 double wp0_altitude_m = _wp0_altitude_node->getDoubleValue()
325 double wp0_course_deg = _wp0_course_node->getDoubleValue();
326 double wp0_distance, wp0_bearing_deg, wp0_course_deviation_deg,
327 wp0_course_error_m, wp0_TTW, wp0_bearing_error_deg;
328 string wp0_ID = _wp0_ID_node->getStringValue();
330 // Get waypoint 1 position
331 double wp1_longitude_deg = _wp1_longitude_node->getDoubleValue();
332 double wp1_latitude_deg = _wp1_latitude_node->getDoubleValue();
333 double wp1_altitude_m = _wp1_altitude_node->getDoubleValue()
335 double wp1_course_deg = _wp1_course_node->getDoubleValue();
336 double wp1_distance, wp1_bearing_deg, wp1_course_deviation_deg,
337 wp1_course_error_m, wp1_TTW, wp1_bearing_error_deg;
338 string wp1_ID = _wp1_ID_node->getStringValue();
340 // If the get-nearest-airport-node is true.
341 // Get the nearest airport, and set it as waypoint 1.
342 if (_get_nearest_airport_node->getBoolValue()) {
343 const FGAirport* a = globals->get_airports()->search(longitude_deg, latitude_deg, false);
345 _wp1_ID_node->setStringValue(a->getId().c_str());
346 wp1_longitude_deg = a->getLongitude();
347 wp1_latitude_deg = a->getLatitude();
348 _wp1_name_node->setStringValue(a->getName().c_str());
349 _get_nearest_airport_node->setBoolValue(false);
350 _last_wp1_ID = wp1_ID = a->getId().c_str();
354 // If the waypoint 0 ID has changed, try to find the new ID
355 // in the airport-, fix-, nav-database.
356 if ( !(_last_wp0_ID == wp0_ID) ) {
357 string waypont_type =
358 _wp0_waypoint_type_node->getStringValue();
359 if (waypont_type == "airport") {
360 const FGAirport* a = globals->get_airports()->search( wp0_ID );
362 wp0_longitude_deg = a->getLongitude();
363 wp0_latitude_deg = a->getLatitude();
364 _wp0_name_node->setStringValue(a->getName().c_str());
367 else if (waypont_type == "nav") {
369 = globals->get_navlist()->findByIdent(wp0_ID.c_str(),
373 //cout << "Nav found" << endl;
374 wp0_longitude_deg = n->get_lon();
375 wp0_latitude_deg = n->get_lat();
376 _wp0_name_node->setStringValue(n->get_name().c_str());
379 else if (waypont_type == "fix") {
381 if ( globals->get_fixlist()->query(wp0_ID, &f) ) {
382 //cout << "Fix found" << endl;
383 wp0_longitude_deg = f.get_lon();
384 wp0_latitude_deg = f.get_lat();
385 _wp0_name_node->setStringValue(wp0_ID.c_str());
388 _last_wp0_ID = wp0_ID;
391 // If the waypoint 1 ID has changed, try to find the new ID
392 // in the airport-, fix-, nav-database.
393 if ( !(_last_wp1_ID == wp1_ID) ) {
394 string waypont_type =
395 _wp1_waypoint_type_node->getStringValue();
396 if (waypont_type == "airport") {
397 const FGAirport* a = globals->get_airports()->search( wp1_ID );
399 wp1_longitude_deg = a->getLongitude();
400 wp1_latitude_deg = a->getLatitude();
401 _wp1_name_node->setStringValue(a->getName().c_str());
404 else if (waypont_type == "nav") {
406 = globals->get_navlist()->findByIdent(wp1_ID.c_str(),
410 //cout << "Nav found" << endl;
411 wp1_longitude_deg = n->get_lon();
412 wp1_latitude_deg = n->get_lat();
413 _wp1_name_node->setStringValue(n->get_name().c_str());
416 else if (waypont_type == "fix") {
418 if ( globals->get_fixlist()->query(wp1_ID, &f) ) {
419 //cout << "Fix found" << endl;
420 wp1_longitude_deg = f.get_lon();
421 wp1_latitude_deg = f.get_lat();
422 _wp1_name_node->setStringValue(wp1_ID.c_str());
425 _last_wp1_ID = wp1_ID;
430 // If any of the two waypoints have changed
431 // we need to calculate a new course between them,
432 // and values for vertical navigation.
433 if ( wp0_longitude_deg != _wp0_longitude_deg ||
434 wp0_latitude_deg != _wp0_latitude_deg ||
435 wp0_altitude_m != _wp0_altitude_m ||
436 wp1_longitude_deg != _wp1_longitude_deg ||
437 wp1_latitude_deg != _wp1_latitude_deg ||
438 wp1_altitude_m != _wp1_altitude_m )
440 // Update the global variables
441 _wp0_longitude_deg = wp0_longitude_deg;
442 _wp0_latitude_deg = wp0_latitude_deg;
443 _wp0_altitude_m = wp0_altitude_m;
444 _wp1_longitude_deg = wp1_longitude_deg;
445 _wp1_latitude_deg = wp1_latitude_deg;
446 _wp1_altitude_m = wp1_altitude_m;
448 // Get the course and distance from wp0 to wp1
449 SGWayPoint wp0(wp0_longitude_deg,
450 wp0_latitude_deg, wp0_altitude_m);
451 SGWayPoint wp1(wp1_longitude_deg,
452 wp1_latitude_deg, wp1_altitude_m);
454 wp1.CourseAndDistance(wp0, &_course_deg, &_distance_m);
455 double leg_mag_course = _course_deg - magvar_deg;
456 SG_NORMALIZE_RANGE(leg_mag_course, 0.0, 360.0);
458 // Get the altitude / distance ratio
459 if ( distance_m > 0.0 ) {
460 double alt_difference_m = wp0_altitude_m - wp1_altitude_m;
461 _alt_dist_ratio = alt_difference_m / _distance_m;
464 _leg_distance_node->setDoubleValue(_distance_m * SG_METER_TO_NM);
465 _leg_course_node->setDoubleValue(_course_deg);
466 _leg_magnetic_course_node->setDoubleValue(leg_mag_course);
467 _alt_dist_ratio_node->setDoubleValue(_alt_dist_ratio);
469 _wp0_longitude_node->setDoubleValue(wp0_longitude_deg);
470 _wp0_latitude_node->setDoubleValue(wp0_latitude_deg);
471 _wp1_longitude_node->setDoubleValue(wp1_longitude_deg);
472 _wp1_latitude_node->setDoubleValue(wp1_latitude_deg);
476 // Find the bearing and distance to waypoint 0.
477 SGWayPoint wp0(wp0_longitude_deg, wp0_latitude_deg, wp0_altitude_m);
478 wp0.CourseAndDistance(longitude_deg, latitude_deg, altitude_m,
479 &wp0_bearing_deg, &wp0_distance);
480 _wp0_distance_node->setDoubleValue(wp0_distance * SG_METER_TO_NM);
481 _wp0_bearing_node->setDoubleValue(wp0_bearing_deg);
482 double wp0_mag_bearing_deg = wp0_bearing_deg - magvar_deg;
483 SG_NORMALIZE_RANGE(wp0_mag_bearing_deg, 0.0, 360.0);
484 _wp0_mag_bearing_node->setDoubleValue(wp0_mag_bearing_deg);
485 wp0_bearing_error_deg = track1_deg - wp0_bearing_deg;
486 SG_NORMALIZE_RANGE(wp0_bearing_error_deg, -180.0, 180.0);
487 _true_wp0_bearing_error_node->setDoubleValue(wp0_bearing_error_deg);
489 // Estimate time to waypoint 0.
490 // The estimation does not take track into consideration,
491 // so if you are going away from the waypoint the TTW will
492 // increase. Makes most sense when travelling directly towards
494 if (speed_kt > 0.0 && wp0_distance > 0.0) {
495 wp0_TTW = (wp0_distance * SG_METER_TO_NM) / (speed_kt / 3600);
500 unsigned int wp0_TTW_seconds = (int) (wp0_TTW + 0.5);
501 if (wp0_TTW_seconds < 356400) { // That's 99 hours
502 unsigned int wp0_TTW_minutes = 0;
503 unsigned int wp0_TTW_hours = 0;
505 while (wp0_TTW_seconds >= 3600) {
506 wp0_TTW_seconds -= 3600;
509 while (wp0_TTW_seconds >= 60) {
510 wp0_TTW_seconds -= 60;
513 snprintf(wp0_TTW_str, 9, "%02d:%02d:%02d",
514 wp0_TTW_hours, wp0_TTW_minutes, wp0_TTW_seconds);
515 _wp0_ttw_node->setStringValue(wp0_TTW_str);
518 _wp0_ttw_node->setStringValue("--:--:--");
520 // Course deviation is the diffenrence between the bearing
522 wp0_course_deviation_deg = wp0_bearing_deg -
524 SG_NORMALIZE_RANGE(wp0_course_deviation_deg, -180.0, 180.0);
526 // If the course deviation is less than 90 degrees to either side,
527 // our desired course is towards the waypoint.
528 // It does not matter if we are actually moving
529 // towards or from the waypoint.
530 if (fabs(wp0_course_deviation_deg) < 90.0) {
531 _wp0_to_flag_node->setBoolValue(true); }
532 // If it's more than 90 degrees the desired
533 // course is from the waypoint.
534 else if (fabs(wp0_course_deviation_deg) > 90.0) {
535 _wp0_to_flag_node->setBoolValue(false);
536 // When the course is away from the waypoint,
537 // it makes sense to change the sign of the deviation.
538 wp0_course_deviation_deg *= -1.0;
539 SG_NORMALIZE_RANGE(wp0_course_deviation_deg, -90.0, 90.0);
542 _wp0_course_deviation_node->setDoubleValue(wp0_course_deviation_deg);
544 // Cross track error.
545 wp0_course_error_m = sin(wp0_course_deviation_deg * SG_PI / 180.0)
547 _wp0_course_error_nm_node->setDoubleValue(wp0_course_error_m
552 // Find the bearing and distance to waypoint 1.
553 SGWayPoint wp1(wp1_longitude_deg, wp1_latitude_deg, wp1_altitude_m);
554 wp1.CourseAndDistance(longitude_deg, latitude_deg, altitude_m,
555 &wp1_bearing_deg, &wp1_distance);
556 _wp1_distance_node->setDoubleValue(wp1_distance * SG_METER_TO_NM);
557 _wp1_bearing_node->setDoubleValue(wp1_bearing_deg);
558 double wp1_mag_bearing_deg = wp1_bearing_deg - magvar_deg;
559 SG_NORMALIZE_RANGE(wp1_mag_bearing_deg, 0.0, 360.0);
560 _wp1_mag_bearing_node->setDoubleValue(wp1_mag_bearing_deg);
561 wp1_bearing_error_deg = track1_deg - wp1_bearing_deg;
562 SG_NORMALIZE_RANGE(wp1_bearing_error_deg, -180.0, 180.0);
563 _true_wp1_bearing_error_node->setDoubleValue(wp1_bearing_error_deg);
565 // Estimate time to waypoint 1.
566 // The estimation does not take track into consideration,
567 // so if you are going away from the waypoint the TTW will
568 // increase. Makes most sense when travelling directly towards
570 if (speed_kt > 0.0 && wp1_distance > 0.0) {
571 wp1_TTW = (wp1_distance * SG_METER_TO_NM) / (speed_kt / 3600);
576 unsigned int wp1_TTW_seconds = (int) (wp1_TTW + 0.5);
577 if (wp1_TTW_seconds < 356400) { // That's 99 hours
578 unsigned int wp1_TTW_minutes = 0;
579 unsigned int wp1_TTW_hours = 0;
581 while (wp1_TTW_seconds >= 3600) {
582 wp1_TTW_seconds -= 3600;
585 while (wp1_TTW_seconds >= 60) {
586 wp1_TTW_seconds -= 60;
589 snprintf(wp1_TTW_str, 9, "%02d:%02d:%02d",
590 wp1_TTW_hours, wp1_TTW_minutes, wp1_TTW_seconds);
591 _wp1_ttw_node->setStringValue(wp1_TTW_str);
594 _wp1_ttw_node->setStringValue("--:--:--");
596 // Course deviation is the diffenrence between the bearing
598 wp1_course_deviation_deg = wp1_bearing_deg - wp1_course_deg;
599 SG_NORMALIZE_RANGE(wp1_course_deviation_deg, -180.0, 180.0);
601 // If the course deviation is less than 90 degrees to either side,
602 // our desired course is towards the waypoint.
603 // It does not matter if we are actually moving
604 // towards or from the waypoint.
605 if (fabs(wp1_course_deviation_deg) < 90.0) {
606 _wp1_to_flag_node->setBoolValue(true); }
607 // If it's more than 90 degrees the desired
608 // course is from the waypoint.
609 else if (fabs(wp1_course_deviation_deg) > 90.0) {
610 _wp1_to_flag_node->setBoolValue(false);
611 // When the course is away from the waypoint,
612 // it makes sense to change the sign of the deviation.
613 wp1_course_deviation_deg *= -1.0;
614 SG_NORMALIZE_RANGE(wp1_course_deviation_deg, -90.0, 90.0);
617 _wp1_course_deviation_node->setDoubleValue(wp1_course_deviation_deg);
619 // Cross track error.
620 wp1_course_error_m = sin(wp1_course_deviation_deg * SG_PI / 180.0)
622 _wp1_course_error_nm_node->setDoubleValue(wp1_course_error_m
626 // Leg course deviation is the diffenrence between the bearing
628 double course_deviation_deg = wp1_bearing_deg - _course_deg;
629 SG_NORMALIZE_RANGE(course_deviation_deg, -180.0, 180.0);
631 // If the course deviation is less than 90 degrees to either side,
632 // our desired course is towards the waypoint.
633 // It does not matter if we are actually moving
634 // towards or from the waypoint.
635 if (fabs(course_deviation_deg) < 90.0) {
636 _leg_to_flag_node->setBoolValue(true); }
637 // If it's more than 90 degrees the desired
638 // course is from the waypoint.
639 else if (fabs(course_deviation_deg) > 90.0) {
640 _leg_to_flag_node->setBoolValue(false);
641 // When the course is away from the waypoint,
642 // it makes sense to change the sign of the deviation.
643 course_deviation_deg *= -1.0;
644 SG_NORMALIZE_RANGE(course_deviation_deg, -90.0, 90.0);
647 _leg_course_deviation_node->setDoubleValue(course_deviation_deg);
649 // Cross track error.
650 double course_error_m = sin(course_deviation_deg * SG_PI / 180.0)
652 _leg_course_error_nm_node->setDoubleValue(course_error_m * SG_METER_TO_NM);
654 // Altitude deviation
655 double desired_altitude_m = wp1_altitude_m
656 + wp1_distance * _alt_dist_ratio;
657 double altitude_deviation_m = altitude_m - desired_altitude_m;
658 _alt_deviation_node->setDoubleValue(altitude_deviation_m * SG_METER_TO_FEET);
663 double tracking_bug = _tracking_bug_node->getDoubleValue();
664 double true_bug_error = tracking_bug - track1_deg;
665 double magnetic_bug_error = tracking_bug - mag_track_bearing;
667 // Get the errors into the (-180,180) range.
668 SG_NORMALIZE_RANGE(true_bug_error, -180.0, 180.0);
669 SG_NORMALIZE_RANGE(magnetic_bug_error, -180.0, 180.0);
671 _true_bug_error_node->setDoubleValue(true_bug_error);
672 _magnetic_bug_error_node->setDoubleValue(magnetic_bug_error);
675 // Add WP 1 to the route.
676 if ( addWp->getBoolValue() )
678 addWp->setBoolValue(false);
680 SGWayPoint tempWp( _wp1_longitude_node->getDoubleValue(),
681 _wp1_latitude_node->getDoubleValue(),
682 _wp1_altitude_node->getDoubleValue(),
684 _wp1_ID_node->getStringValue(),
685 _wp1_name_node->getStringValue() );
687 route->add_waypoint(tempWp);
690 _route->getChild("Waypoint", route->size()-1, true);
691 SGPropertyNode *id = wp->getChild("ID", 0, true);
692 SGPropertyNode *name = wp->getChild("Name", 0, true);
693 SGPropertyNode *lat = wp->getChild("Latitude", 0, true);
694 SGPropertyNode *lon = wp->getChild("Longitude", 0, true);
695 SGPropertyNode *alt = wp->getChild("Altitude", 0, true);
697 id->setStringValue( tempWp.get_id().c_str() );
698 name->setStringValue( tempWp.get_name().c_str() );
699 lat->setDoubleValue( tempWp.get_target_lat() );
700 lon->setDoubleValue( tempWp.get_target_lon() );
701 alt->setDoubleValue( tempWp.get_target_alt() );
704 if ( popWp->getBoolValue() )
706 popWp->setBoolValue(false);
708 route->delete_first();
709 _route->removeChild("Waypoint", 0, false);
713 _true_track_node->setDoubleValue(0.0);
714 _magnetic_track_node->setDoubleValue(0.0);
715 _speed_node->setDoubleValue(0.0);
719 _last_longitude_deg = longitude_deg;
720 _last_latitude_deg = latitude_deg;
721 _last_altitude_m = altitude_m;