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flightgear/src/Navaids/navdb.cxx
2006-10-17 21:21:26 +00:00

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9.7 KiB
C++

// navdb.cxx -- top level navaids management routines
//
// Written by Curtis Olson, started May 2004.
//
// Copyright (C) 2004 Curtis L. Olson - http://www.flightgear.org/~curt
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License as
// published by the Free Software Foundation; either version 2 of the
// License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
//
// $Id$
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <simgear/compiler.h>
#include STL_STRING
#include <simgear/debug/logstream.hxx>
#include <Airports/runways.hxx>
#include <Airports/simple.hxx>
#include <Main/globals.hxx>
#include "navrecord.hxx"
#include "navdb.hxx"
SG_USING_STD( string );
// load and initialize the navigational databases
bool fgNavDBInit( FGAirportList *airports,
FGNavList *navlist, FGNavList *loclist, FGNavList *gslist,
FGNavList *dmelist, FGNavList *mkrlist,
FGNavList *tacanlist, FGNavList *carrierlist,
FGTACANList *channellist)
{
SG_LOG(SG_GENERAL, SG_INFO, "Loading Navaid Databases");
// SG_LOG(SG_GENERAL, SG_INFO, " VOR/NDB");
// SGPath p_nav( globals->get_fg_root() );
// p_nav.append( "Navaids/default.nav" );
// navlist->init( p_nav );
// SG_LOG(SG_GENERAL, SG_INFO, " ILS and Marker Beacons");
// beacons->init();
// SGPath p_ils( globals->get_fg_root() );
// p_ils.append( "Navaids/default.ils" );
// ilslist->init( p_ils );
SGPath path( globals->get_fg_root() );
path.append( "Navaids/nav.dat" );
sg_gzifstream in( path.str() );
if ( !in.is_open() ) {
SG_LOG( SG_GENERAL, SG_ALERT, "Cannot open file: " << path.str() );
exit(-1);
}
// skip first two lines
in >> skipeol;
in >> skipeol;
#ifdef __MWERKS__
char c = 0;
while ( in.get(c) && c != '\0' ) {
in.putback(c);
#else
while ( ! in.eof() ) {
#endif
FGNavRecord *r = new FGNavRecord;
in >> (*r);
if ( r->get_type() > 95 ) {
break;
}
/*cout << "id = " << r->get_ident() << endl;
cout << " type = " << r->get_type() << endl;
cout << " lon = " << r->get_lon() << endl;
cout << " lat = " << r->get_lat() << endl;
cout << " elev = " <<r->get_elev_ft() << endl;
cout << " freq = " << r->get_freq() << endl;
cout << " range = " << r->get_range() << endl;
cout << " name = " << r->get_name() << endl << endl; */
// fudge elevation to the field elevation if it's not specified
if ( fabs(r->get_elev_ft()) < 0.01 && r->get_apt_id().length() ) {
// cout << r->get_type() << " " << r->get_apt_id() << " zero elev"
// << endl;
const FGAirport* a = airports->search( r->get_apt_id() );
if ( a ) {
r->set_elev_ft( a->getElevation() );
// cout << " setting to " << a.elevation << endl;
}
}
if ( r->get_type() == 2 || r->get_type() == 3 ) {
// NDB=2, VOR=3
navlist->add( r );
} else if ( r->get_type() == 4 || r->get_type() == 5 ) {
// ILS=4, LOC(only)=5
loclist->add( r );
} else if ( r->get_type() == 6 ) {
// GS=6
gslist->add( r );
} else if ( r->get_type() == 7 || r->get_type() == 8
|| r->get_type() == 9 )
{
// Marker Beacon = 7,8,9
mkrlist->add( r );
} else if ( r->get_type() == 12 || r->get_type() == 13) {
// DME with ILS=12; standalone DME=13
string str1( r->get_name() );
string::size_type loc1= str1.find( "TACAN", 0 );
string::size_type loc2 = str1.find( "VORTAC", 0 );
if( loc1 != string::npos || loc2 != string::npos ){
//cout << " name = " << r->get_name() ;
//cout << " freq = " << r->get_freq() ;
tacanlist->add( r );
}
dmelist->add( r );
}
in >> skipcomment;
}
// load the carrier navaids file
string file, name;
path = "";
path = globals->get_fg_root() ;
path.append( "Navaids/carrier_nav.dat" );
file = path.str();
SG_LOG( SG_GENERAL, SG_INFO, "opening file: " << path.str() );
sg_gzifstream incarrier( path.str() );
if ( !incarrier.is_open() ) {
SG_LOG( SG_GENERAL, SG_ALERT, "Cannot open file: " << path.str() );
exit(-1);
}
// skip first two lines
//incarrier >> skipeol;
//incarrier >> skipeol;
#ifdef __MWERKS__
char c = 0;
while ( incarrier.get(c) && c != '\0' ) {
incarrier.putback(c);
#else
while ( ! incarrier.eof() ) {
#endif
FGNavRecord *r = new FGNavRecord;
incarrier >> (*r);
carrierlist->add ( r );
/*cout << " carrier lon: "<< r->get_lon() ;
cout << " carrier lat: "<< r->get_lat() ;
cout << " freq: " << r->get_freq() ;
cout << " carrier name: "<< r->get_name() << endl;*/
//if ( r->get_type() > 95 ) {
// break;}
} // end while
// end loading the carrier navaids file
// load the channel/freqency file
string channel, freq;
path="";
path = globals->get_fg_root();
path.append( "Navaids/TACAN_freq.dat" );
SG_LOG( SG_GENERAL, SG_INFO, "opening file: " << path.str() );
sg_gzifstream inchannel( path.str() );
if ( !inchannel.is_open() ) {
SG_LOG( SG_GENERAL, SG_ALERT, "Cannot open file: " << path.str() );
exit(-1);
}
// skip first line
inchannel >> skipeol;
#ifdef __MWERKS__
char c = 0;
while ( inchannel.get(c) && c != '\0' ) {
in.putback(c);
#else
while ( ! inchannel.eof() ) {
#endif
FGTACANRecord *r = new FGTACANRecord;
inchannel >> (*r);
channellist->add ( r );
//cout << "channel = " << r->get_channel() ;
//cout << " freq = " << r->get_freq() << endl;
} // end while
// end ReadChanFile
return true;
}
// Given a localizer record and it's corresponding runway record,
// adjust the localizer position so it is in perfect alignment with
// the runway.
static void update_loc_position( FGNavRecord *loc, FGRunway *rwy,
double threshold )
{
double hdg = rwy->_heading;
hdg += 180.0;
if ( hdg > 360.0 ) {
hdg -= 360.0;
}
// calculate runway threshold point
double thresh_lat, thresh_lon, return_az;
geo_direct_wgs_84 ( 0.0, rwy->_lat, rwy->_lon, hdg,
rwy->_length/2.0 * SG_FEET_TO_METER,
&thresh_lat, &thresh_lon, &return_az );
// cout << "Threshold = " << thresh_lat << "," << thresh_lon << endl;
// calculate distance from threshold to localizer
double az1, az2, dist_m;
geo_inverse_wgs_84( 0.0, loc->get_lat(), loc->get_lon(),
thresh_lat, thresh_lon,
&az1, &az2, &dist_m );
// cout << "Distance = " << dist_m << endl;
// back project that distance along the runway center line
double nloc_lat, nloc_lon;
geo_direct_wgs_84 ( 0.0, thresh_lat, thresh_lon, hdg + 180.0,
dist_m, &nloc_lat, &nloc_lon, &return_az );
// printf("New localizer = %.6f %.6f\n", nloc_lat, nloc_lon );
// sanity check, how far have we moved the localizer?
geo_inverse_wgs_84( 0.0, loc->get_lat(), loc->get_lon(),
nloc_lat, nloc_lon,
&az1, &az2, &dist_m );
// cout << "Distance moved = " << dist_m << endl;
// cout << "orig heading = " << loc->get_multiuse() << endl;
// cout << "new heading = " << rwy->_heading << endl;
double hdg_diff = loc->get_multiuse() - rwy->_heading;
// clamp to [-180.0 ... 180.0]
if ( hdg_diff < -180.0 ) {
hdg_diff += 360.0;
} else if ( hdg_diff > 180.0 ) {
hdg_diff -= 360.0;
}
if ( fabs(hdg_diff) <= threshold ) {
loc->set_lat( nloc_lat );
loc->set_lon( nloc_lon );
loc->set_multiuse( rwy->_heading );
}
}
// This routines traverses the localizer list and attempts to match
// each entry with it's corresponding runway. When it is successful,
// it then "moves" the localizer and updates it's heading so it
// *perfectly* aligns with the runway, but is still the same distance
// from the runway threshold.
void fgNavDBAlignLOCwithRunway( FGRunwayList *runways, FGNavList *loclist,
double threshold ) {
nav_map_type navmap = loclist->get_navaids();
nav_map_const_iterator freq = navmap.begin();
while ( freq != navmap.end() ) {
nav_list_type locs = freq->second;
nav_list_const_iterator loc = locs.begin();
while ( loc != locs.end() ) {
string name = (*loc)->get_name();
string::size_type pos1 = name.find(" ");
string id = name.substr(0, pos1);
name = name.substr(pos1+1);
string::size_type pos2 = name.find(" ");
string rwy = name.substr(0, pos2);
FGRunway r;
if ( runways->search(id, rwy, &r) ) {
update_loc_position( (*loc), &r, threshold );
}
++loc;
}
++freq;
}
}