1 // navcom.cxx -- class to manage a navcom instance
3 // Written by Curtis Olson, started April 2000.
5 // Copyright (C) 2000 - 2002 Curtis L. Olson - curt@flightgear.org
7 // This program is free software; you can redistribute it and/or
8 // modify it under the terms of the GNU General Public License as
9 // published by the Free Software Foundation; either version 2 of the
10 // License, or (at your option) any later version.
12 // This program is distributed in the hope that it will be useful, but
13 // WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 // General Public License for more details.
17 // You should have received a copy of the GNU General Public License
18 // along with this program; if not, write to the Free Software
19 // Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28 #include <stdio.h> // snprintf
30 #include <simgear/compiler.h>
31 #include <simgear/math/sg_random.h>
33 #include <Aircraft/aircraft.hxx>
34 #include <Navaids/ilslist.hxx>
35 #include <Navaids/navlist.hxx>
36 #include <Time/FGEventMgr.hxx>
45 * Boy, this is ugly! Make the VOR range vary by altitude difference.
47 static double kludgeRange ( double stationElev, double aircraftElev,
50 // Assume that the nominal range (usually 50nm) applies at a 5,000
51 // ft difference. Just a wild guess!
52 double factor = ((aircraftElev*SG_METER_TO_FEET) - stationElev) / 5000.0;
53 double range = fabs(nominalRange * factor);
55 // Clamp the range to keep it sane; for now, never less than 25%
56 // or more than 500% of nominal range.
57 if (range < nominalRange/4.0) {
58 range = nominalRange/4.0;
59 } else if (range > nominalRange*5.0) {
60 range = nominalRange*5.0;
68 FGNavCom::FGNavCom() :
69 lon_node(fgGetNode("/position/longitude-deg", true)),
70 lat_node(fgGetNode("/position/latitude-deg", true)),
71 alt_node(fgGetNode("/position/altitude-ft", true)),
87 SGPath path( globals->get_fg_root() );
89 term.append( "Navaids/range.term" );
91 low.append( "Navaids/range.low" );
93 high.append( "Navaids/range.high" );
95 term_tbl = new SGInterpTable( term.str() );
96 low_tbl = new SGInterpTable( low.str() );
97 high_tbl = new SGInterpTable( high.str() );
103 FGNavCom::~FGNavCom()
118 update(0); // FIXME: use dt
127 sprintf( propname, "/radios/comm[%d]/inputs/power-btn", index );
128 fgTie( propname, this,
129 &FGNavCom::get_power_btn, &FGNavCom::set_power_btn );
130 fgSetArchivable( propname );
132 sprintf( propname, "/radios/comm[%d]/frequencies/selected-mhz", index );
133 fgTie( propname, this, &FGNavCom::get_comm_freq, &FGNavCom::set_comm_freq );
134 fgSetArchivable( propname );
136 sprintf( propname, "/radios/comm[%d]/frequencies/standby-mhz", index );
137 fgTie( propname, this,
138 &FGNavCom::get_comm_alt_freq, &FGNavCom::set_comm_alt_freq );
139 fgSetArchivable( propname );
141 sprintf( propname, "/radios/comm[%d]/volume", index );
142 fgTie( propname, this,
143 &FGNavCom::get_comm_vol_btn, &FGNavCom::set_comm_vol_btn );
144 fgSetArchivable( propname );
146 sprintf( propname, "/radios/nav[%d]/frequencies/selected-mhz", index );
147 fgTie( propname, this,
148 &FGNavCom::get_nav_freq, &FGNavCom::set_nav_freq );
149 fgSetArchivable( propname );
151 sprintf( propname, "/radios/nav[%d]/frequencies/standby-mhz", index );
152 fgTie( propname , this,
153 &FGNavCom::get_nav_alt_freq, &FGNavCom::set_nav_alt_freq);
154 fgSetArchivable( propname );
156 sprintf( propname, "/radios/nav[%d]/radials/selected-deg", index );
157 fgTie( propname, this,
158 &FGNavCom::get_nav_sel_radial, &FGNavCom::set_nav_sel_radial );
159 fgSetArchivable( propname );
161 sprintf( propname, "/radios/nav[%d]/volume", index );
162 fgTie( propname, this,
163 &FGNavCom::get_nav_vol_btn, &FGNavCom::set_nav_vol_btn );
164 fgSetArchivable( propname );
166 sprintf( propname, "/radios/nav[%d]/ident", index );
167 fgTie( propname, this,
168 &FGNavCom::get_nav_ident_btn, &FGNavCom::set_nav_ident_btn );
169 fgSetArchivable( propname );
172 sprintf( propname, "/radios/nav[%d]/radials/actual-deg", index );
173 fgTie( propname, this, &FGNavCom::get_nav_radial );
175 sprintf( propname, "/radios/nav[%d]/to-flag", index );
176 fgTie( propname, this, &FGNavCom::get_nav_to_flag );
178 sprintf( propname, "/radios/nav[%d]/from-flag", index );
179 fgTie( propname, this, &FGNavCom::get_nav_from_flag );
181 sprintf( propname, "/radios/nav[%d]/in-range", index );
182 fgTie( propname, this, &FGNavCom::get_nav_inrange );
184 sprintf( propname, "/radios/nav[%d]/heading-needle-deflection", index );
185 fgTie( propname, this, &FGNavCom::get_nav_heading_needle_deflection );
187 sprintf( propname, "/radios/nav[%d]/gs-needle-deflection", index );
188 fgTie( propname, this, &FGNavCom::get_nav_gs_needle_deflection );
197 sprintf( propname, "/radios/comm[%d]/inputs/power-btn", index );
199 sprintf( propname, "/radios/comm[%d]/frequencies/selected-mhz", index );
201 sprintf( propname, "/radios/comm[%d]/frequencies/standby-mhz", index );
204 sprintf( propname, "/radios/nav[%d]/frequencies/selected-mhz", index );
206 sprintf( propname, "/radios/nav[%d]/frequencies/standby-mhz", index );
208 sprintf( propname, "/radios/nav[%d]/radials/actual-deg", index );
210 sprintf( propname, "/radios/nav[%d]/radials/selected-deg", index );
212 sprintf( propname, "/radios/nav[%d]/ident", index );
214 sprintf( propname, "/radios/nav[%d]/to-flag", index );
216 sprintf( propname, "/radios/nav[%d]/from-flag", index );
218 sprintf( propname, "/radios/nav[%d]/in-range", index );
220 sprintf( propname, "/radios/nav[%d]/heading-needle-deflection", index );
222 sprintf( propname, "/radios/nav[%d]/gs-needle-deflection", index );
227 // model standard VOR/DME/TACAN service volumes as per AIM 1-1-8
228 double FGNavCom::adjustNavRange( double stationElev, double aircraftElev,
229 double nominalRange )
231 // extend out actual usable range to be 1.3x the published safe range
232 const double usability_factor = 1.3;
234 // assumptions we model the standard service volume, plus
235 // ... rather than specifying a cylinder, we model a cone that
236 // contains the cylinder. Then we put an upside down cone on top
237 // to model diminishing returns at too-high altitudes.
239 // altitude difference
240 double alt = ( aircraftElev * SG_METER_TO_FEET - stationElev );
241 // cout << "aircraft elev = " << aircraftElev * SG_METER_TO_FEET
242 // << " station elev = " << stationElev << endl;
244 if ( nominalRange < 25.0 + SG_EPSILON ) {
245 // Standard Terminal Service Volume
246 return term_tbl->interpolate( alt ) * usability_factor;
247 } else if ( nominalRange < 50.0 + SG_EPSILON ) {
248 // Standard Low Altitude Service Volume
249 // table is based on range of 40, scale to actual range
250 return low_tbl->interpolate( alt ) * nominalRange / 40.0
253 // Standard High Altitude Service Volume
254 // table is based on range of 130, scale to actual range
255 return high_tbl->interpolate( alt ) * nominalRange / 130.0
261 // model standard ILS service volumes as per AIM 1-1-9
262 double FGNavCom::adjustILSRange( double stationElev, double aircraftElev,
263 double offsetDegrees, double distance )
265 // assumptions we model the standard service volume, plus
267 // altitude difference
268 // double alt = ( aircraftElev * SG_METER_TO_FEET - stationElev );
269 double offset = fabs( offsetDegrees );
272 return FG_ILS_DEFAULT_RANGE;
273 } else if ( offset < 35 ) {
274 return 10 + (35 - offset) * (FG_ILS_DEFAULT_RANGE - 10) / 25;
275 } else if ( offset < 45 ) {
276 return (45 - offset);
277 } else if ( offset > 170 ) {
278 return FG_ILS_DEFAULT_RANGE;
279 } else if ( offset > 145 ) {
280 return 10 + (offset - 145) * (FG_ILS_DEFAULT_RANGE - 10) / 25;
281 } else if ( offset > 135 ) {
282 return (offset - 135);
289 // Update the various nav values based on position and valid tuned in navs
291 FGNavCom::update(double dt)
293 double lon = lon_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
294 double lat = lat_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
295 double elev = alt_node->getDoubleValue() * SG_FEET_TO_METER;
299 Point3D aircraft = sgGeodToCart( Point3D( lon, lat, elev ) );
303 ////////////////////////////////////////////////////////////////////////
305 ////////////////////////////////////////////////////////////////////////
307 if ( nav_valid && power_btn ) {
308 station = Point3D( nav_x, nav_y, nav_z );
309 nav_loc_dist = aircraft.distance3D( station );
312 station = Point3D( nav_gs_x, nav_gs_y, nav_gs_z );
313 nav_gs_dist = aircraft.distance3D( station );
319 geo_inverse_wgs_84( elev, lat * SGD_RADIANS_TO_DEGREES, lon * SGD_RADIANS_TO_DEGREES,
320 nav_loclat, nav_loclon,
322 // cout << "az1 = " << az1 << " magvar = " << nav_magvar << endl;
323 nav_heading = az1 - nav_magvar;
324 // cout << " heading = " << nav_heading
325 // << " dist = " << nav_dist << endl;
328 double offset = nav_heading - nav_radial;
329 while ( offset < -180.0 ) { offset += 360.0; }
330 while ( offset > 180.0 ) { offset -= 360.0; }
331 // cout << "ils offset = " << offset << endl;
332 nav_effective_range = adjustILSRange(nav_elev, elev, offset,
333 nav_loc_dist * SG_METER_TO_NM );
335 nav_effective_range = adjustNavRange(nav_elev, elev, nav_range);
337 // cout << "nav range = " << nav_effective_range
338 // << " (" << nav_range << ")" << endl;
340 if ( nav_loc_dist < nav_effective_range * SG_NM_TO_METER ) {
342 } else if ( nav_loc_dist < 2 * nav_effective_range * SG_NM_TO_METER ) {
343 nav_inrange = sg_random() <
344 ( 2 * nav_effective_range * SG_NM_TO_METER - nav_loc_dist ) /
345 (nav_effective_range * SG_NM_TO_METER);
351 nav_radial = nav_sel_radial;
355 // cout << "not picking up vor. :-(" << endl;
358 #ifdef ENABLE_AUDIO_SUPPORT
359 if ( nav_valid && nav_inrange ) {
360 // play station ident via audio system if on + ident,
361 // otherwise turn it off
362 if ( power_btn && nav_ident_btn ) {
363 FGSimpleSound *sound;
364 sound = globals->get_soundmgr()->find( nav_fx_name );
365 if ( sound != NULL ) {
366 sound->set_volume( nav_vol_btn );
368 SG_LOG( SG_COCKPIT, SG_ALERT,
369 "Can't find nav-vor-ident sound" );
371 sound = globals->get_soundmgr()->find( dme_fx_name );
372 if ( sound != NULL ) {
373 sound->set_volume( nav_vol_btn );
375 SG_LOG( SG_COCKPIT, SG_ALERT,
376 "Can't find nav-dme-ident sound" );
378 // cout << "nav_last_time = " << nav_last_time << " ";
379 // cout << "cur_time = "
380 // << globals->get_time_params()->get_cur_time();
382 globals->get_time_params()->get_cur_time() - 30 ) {
383 nav_last_time = globals->get_time_params()->get_cur_time();
386 // cout << " nav_play_count = " << nav_play_count << endl;
387 // cout << "playing = "
388 // << globals->get_soundmgr()->is_playing(nav_fx_name)
390 if ( nav_play_count < 4 ) {
392 if ( !globals->get_soundmgr()->is_playing(nav_fx_name) ) {
393 globals->get_soundmgr()->play_once( nav_fx_name );
396 } else if ( nav_play_count < 5 && nav_has_dme ) {
398 if ( !globals->get_soundmgr()->is_playing(nav_fx_name) &&
399 !globals->get_soundmgr()->is_playing(dme_fx_name) ) {
400 globals->get_soundmgr()->play_once( dme_fx_name );
405 globals->get_soundmgr()->stop( nav_fx_name );
406 globals->get_soundmgr()->stop( dme_fx_name );
414 // Update current nav/adf radio stations based on current postition
415 void FGNavCom::search()
417 double lon = lon_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
418 double lat = lat_node->getDoubleValue() * SGD_DEGREES_TO_RADIANS;
419 double elev = alt_node->getDoubleValue() * SG_FEET_TO_METER;
424 ////////////////////////////////////////////////////////////////////////
426 ////////////////////////////////////////////////////////////////////////
428 if ( current_ilslist->query( lon, lat, elev, nav_freq, &ils ) ) {
429 nav_id = ils.get_locident();
431 if ( last_nav_id != nav_id || last_nav_vor ) {
432 nav_trans_ident = ils.get_trans_ident();
433 last_nav_id = nav_id;
434 last_nav_vor = false;
436 nav_has_dme = ils.get_has_dme();
437 nav_has_gs = ils.get_has_gs();
439 nav_loclon = ils.get_loclon();
440 nav_loclat = ils.get_loclat();
441 nav_gslon = ils.get_gslon();
442 nav_gslat = ils.get_gslat();
443 nav_elev = ils.get_gselev();
445 nav_range = FG_ILS_DEFAULT_RANGE;
446 nav_effective_range = nav_range;
447 nav_target_gs = ils.get_gsangle();
448 nav_radial = ils.get_locheading();
449 while ( nav_radial < 0.0 ) { nav_radial += 360.0; }
450 while ( nav_radial > 360.0 ) { nav_radial -= 360.0; }
454 nav_gs_x = ils.get_gs_x();
455 nav_gs_y = ils.get_gs_y();
456 nav_gs_z = ils.get_gs_z();
458 #ifdef ENABLE_AUDIO_SUPPORT
459 if ( globals->get_soundmgr()->exists( nav_fx_name ) ) {
460 globals->get_soundmgr()->remove( nav_fx_name );
462 FGSimpleSound *sound;
463 sound = morse.make_ident( nav_trans_ident, LO_FREQUENCY );
464 sound->set_volume( 0.3 );
465 globals->get_soundmgr()->add( sound, nav_fx_name );
467 if ( globals->get_soundmgr()->exists( dme_fx_name ) ) {
468 globals->get_soundmgr()->remove( dme_fx_name );
470 sound = morse.make_ident( nav_trans_ident, HI_FREQUENCY );
471 sound->set_volume( 0.3 );
472 globals->get_soundmgr()->add( sound, dme_fx_name );
474 int offset = (int)(sg_random() * 30.0);
475 nav_play_count = offset / 4;
476 nav_last_time = globals->get_time_params()->get_cur_time() -
478 // cout << "offset = " << offset << " play_count = "
480 // << " nav_last_time = " << nav_last_time
481 // << " current time = "
482 // << globals->get_time_params()->get_cur_time() << endl;
485 // cout << "Found an ils station in range" << endl;
486 // cout << " id = " << ils.get_locident() << endl;
488 } else if ( current_navlist->query( lon, lat, elev, nav_freq, &nav ) ) {
489 nav_id = nav.get_ident();
491 if ( last_nav_id != nav_id || !last_nav_vor ) {
492 last_nav_id = nav_id;
494 nav_trans_ident = nav.get_trans_ident();
496 nav_has_dme = nav.get_has_dme();
498 nav_loclon = nav.get_lon();
499 nav_loclat = nav.get_lat();
500 nav_elev = nav.get_elev();
501 nav_magvar = nav.get_magvar();
502 nav_range = nav.get_range();
503 nav_effective_range = adjustNavRange(nav_elev, elev, nav_range);
505 nav_radial = nav_sel_radial;
510 #ifdef ENABLE_AUDIO_SUPPORT
511 if ( globals->get_soundmgr()->exists( nav_fx_name ) ) {
512 globals->get_soundmgr()->remove( nav_fx_name );
514 FGSimpleSound *sound;
515 sound = morse.make_ident( nav_trans_ident, LO_FREQUENCY );
516 sound->set_volume( 0.3 );
517 if ( globals->get_soundmgr()->add( sound, nav_fx_name ) ) {
518 // cout << "Added nav-vor-ident sound" << endl;
520 cout << "Failed to add v1-vor-ident sound" << endl;
523 if ( globals->get_soundmgr()->exists( dme_fx_name ) ) {
524 globals->get_soundmgr()->remove( dme_fx_name );
526 sound = morse.make_ident( nav_trans_ident, HI_FREQUENCY );
527 sound->set_volume( 0.3 );
528 globals->get_soundmgr()->add( sound, dme_fx_name );
530 int offset = (int)(sg_random() * 30.0);
531 nav_play_count = offset / 4;
532 nav_last_time = globals->get_time_params()->get_cur_time() -
534 // cout << "offset = " << offset << " play_count = "
535 // << nav_play_count << " nav_last_time = "
536 // << nav_last_time << " current time = "
537 // << globals->get_time_params()->get_cur_time() << endl;
540 // cout << "Found a vor station in range" << endl;
541 // cout << " id = " << nav.get_ident() << endl;
547 nav_trans_ident = "";
549 #ifdef ENABLE_AUDIO_SUPPORT
550 if ( ! globals->get_soundmgr()->remove( nav_fx_name ) ) {
551 cout << "Failed to remove nav-vor-ident sound" << endl;
553 globals->get_soundmgr()->remove( dme_fx_name );
555 // cout << "not picking up vor1. :-(" << endl;
560 // return the amount of heading needle deflection, returns a value
561 // clamped to the range of ( -10 , 10 )
562 double FGNavCom::get_nav_heading_needle_deflection() const {
566 r = nav_heading - nav_radial;
567 // cout << "Radial = " << nav_radial
568 // << " Bearing = " << nav_heading << endl;
570 while ( r > 180.0 ) { r -= 360.0;}
571 while ( r < -180.0 ) { r += 360.0;}
572 if ( fabs(r) > 90.0 ) {
573 r = ( r<0.0 ? -r-180.0 : -r+180.0 );
579 // According to Robin Peel, the ILS is 4x more sensitive than a vor
580 if ( nav_loc ) { r *= 4.0; }
581 if ( r < -10.0 ) { r = -10.0; }
582 if ( r > 10.0 ) { r = 10.0; }
591 // return the amount of glide slope needle deflection (.i.e. the
592 // number of degrees we are off the glide slope * 5.0
593 double FGNavCom::get_nav_gs_needle_deflection() const {
594 if ( nav_inrange && nav_has_gs ) {
595 double x = nav_gs_dist;
596 double y = (fgGetDouble("/position/altitude-ft") - nav_elev)
598 double angle = atan2( y, x ) * SGD_RADIANS_TO_DEGREES;
599 return (nav_target_gs - angle) * 5.0;
607 * Return true if the NAV TO flag should be active.
610 FGNavCom::get_nav_to_flag () const
613 double offset = fabs(nav_heading - nav_radial);
617 return (offset <= 90.0 || offset >= 270.0);
625 * Return true if the NAV FROM flag should be active.
628 FGNavCom::get_nav_from_flag () const
631 double offset = fabs(nav_heading - nav_radial);
635 return (offset > 90.0 && offset < 270.0);