/* -------------------------------------------------------------------------
* BKG NTRIP Server
* -------------------------------------------------------------------------
*
* Class: bnseph
*
* Purpose: Retrieve broadcast ephemeris from BNC
*
* Author: L. Mervart
*
* Created: 29-Mar-2008
*
* Changes:
*
* -----------------------------------------------------------------------*/
#include <iostream>
#include "bnseph.h"
#include "bnsutils.h"
using namespace std;
// Constructor
////////////////////////////////////////////////////////////////////////////
t_bnseph::t_bnseph(QObject* parent) : QThread(parent) {
this->setTerminationEnabled(true);
_socket = 0;
}
// Destructor
////////////////////////////////////////////////////////////////////////////
t_bnseph::~t_bnseph() {
delete _socket;
}
// Connect the Socket
////////////////////////////////////////////////////////////////////////////
void t_bnseph::reconnect() {
delete _socket;
QSettings settings;
QString host = settings.value("ephHost").toString();
if (host.isEmpty()) {
host = "localhost";
}
int port = settings.value("ephPort").toInt();
_socket = new QTcpSocket();
_socket->connectToHost(host, port);
const int timeOut = 10*1000; // 10 seconds
if (!_socket->waitForConnected(timeOut)) {
emit(newMessage("bnseph::run Connect Timeout"));
}
}
// Start
////////////////////////////////////////////////////////////////////////////
void t_bnseph::run() {
emit(newMessage("bnseph::run Start"));
while (true) {
if (_socket == 0 || _socket->state() != QAbstractSocket::ConnectedState) {
reconnect();
}
if (_socket && _socket->state() == QAbstractSocket::ConnectedState) {
readEph();
}
else {
msleep(10);
}
}
}
// Read One Ephemeris
////////////////////////////////////////////////////////////////////////////
void t_bnseph::readEph() {
t_eph* eph = 0;
QByteArray line = waitForLine(_socket);
QTextStream in(line);
QString prn;
in >> prn;
int numlines = 0;
if (prn.indexOf('R') != -1) {
eph = new t_ephGlo();
numlines = 4;
}
else {
eph = new t_ephGPS();
numlines = 8;
}
QStringList lines;
lines << line;
for (int ii = 2; ii <= numlines; ii++) {
QByteArray line = waitForLine(_socket);
lines << line;
}
eph->read(lines);
emit(newEph(eph));
}
// Compare Time
////////////////////////////////////////////////////////////////////////////
bool t_eph::isNewerThan(const t_eph* eph) const {
if (_GPSweek > eph->_GPSweek ||
(_GPSweek == eph->_GPSweek && _GPSweeks > eph->_GPSweeks)) {
return true;
}
else {
return false;
}
}
// Read GPS Ephemeris
////////////////////////////////////////////////////////////////////////////
void t_ephGPS::read(const QStringList& lines) {
for (int ii = 1; ii <= lines.size(); ii++) {
QTextStream in(lines.at(ii-1).toAscii());
if (ii == 1) {
double year, month, day, hour, minute, second;
in >> _prn >> year >> month >> day >> hour >> minute >> second
>> _clock_bias >> _clock_drift >> _clock_driftrate;
if (year < 100) year += 2000;
QDateTime dateTime(QDate(int(year), int(month), int(day)),
QTime(int(hour), int(minute), int(second)), Qt::UTC);
GPSweekFromDateAndTime(dateTime, _GPSweek, _GPSweeks);
_TOC = _GPSweeks;
}
else if (ii == 2) {
in >> _IODE >> _Crs >> _Delta_n >> _M0;
}
else if (ii == 3) {
in >> _Cuc >> _e >> _Cus >> _sqrt_A;
}
else if (ii == 4) {
in >> _TOE >> _Cic >> _OMEGA0 >> _Cis;
}
else if (ii == 5) {
in >> _i0 >> _Crc >> _omega >> _OMEGADOT;
}
else if (ii == 6) {
in >> _IDOT;
}
else if (ii == 7) {
double hlp, health;
in >> hlp >> health >> _TGD >> _IODC;
}
else if (ii == 8) {
in >> _TOW;
}
}
}
// Compute GPS Satellite Position
////////////////////////////////////////////////////////////////////////////
void t_ephGPS::position(int GPSweek, double GPSweeks, ColumnVector& xc,
ColumnVector& vv) const {
const static double secPerWeek = 7 * 86400.0;
const static double omegaEarth = 7292115.1467e-11;
const static double gmWGS = 398.6005e12;
if (xc.Nrows() < 4) {
xc.ReSize(4);
}
xc = 0.0;
if (vv.Nrows() < 3) {
vv.ReSize(3);
}
vv = 0.0;
double a0 = _sqrt_A * _sqrt_A;
if (a0 == 0) {
return;
}
double n0 = sqrt(gmWGS/(a0*a0*a0));
double tk = GPSweeks - _TOE;
if (GPSweek != _GPSweek) {
tk += (GPSweek - _GPSweek) * secPerWeek;
}
double n = n0 + _Delta_n;
double M = _M0 + n*tk;
double E = M;
double E_last;
do {
E_last = E;
E = M + _e*sin(E);
} while ( fabs(E-E_last)*a0 > 0.001 );
double v = 2.0*atan( sqrt( (1.0 + _e)/(1.0 - _e) )*tan( E/2 ) );
double u0 = v + _omega;
double sin2u0 = sin(2*u0);
double cos2u0 = cos(2*u0);
double r = a0*(1 - _e*cos(E)) + _Crc*cos2u0 + _Crs*sin2u0;
double i = _i0 + _IDOT*tk + _Cic*cos2u0 + _Cis*sin2u0;
double u = u0 + _Cuc*cos2u0 + _Cus*sin2u0;
double xp = r*cos(u);
double yp = r*sin(u);
double OM = _OMEGA0 + (_OMEGADOT - omegaEarth)*tk -
omegaEarth*_TOE;
double sinom = sin(OM);
double cosom = cos(OM);
double sini = sin(i);
double cosi = cos(i);
xc(1) = xp*cosom - yp*cosi*sinom;
xc(2) = xp*sinom + yp*cosi*cosom;
xc(3) = yp*sini;
double tc = GPSweeks - _TOC;
if (GPSweek != _GPSweek) {
tc += (GPSweek - _GPSweek) * secPerWeek;
}
xc(4) = _clock_bias + _clock_drift*tc + _clock_driftrate*tc*tc
- 4.442807633e-10 * _e * sqrt(a0) *sin(E);
// Velocity
// --------
double tanv2 = tan(v/2);
double dEdM = 1 / (1 - _e*cos(E));
double dotv = sqrt((1.0 + _e)/(1.0 - _e)) / cos(E/2)/cos(E/2) / (1 + tanv2*tanv2)
* dEdM * n;
double dotu = dotv + (-_Cuc*sin2u0 + _Cus*cos2u0)*2*dotv;
double dotom = _OMEGADOT - omegaEarth;
double doti = _IDOT + (-_Cic*sin2u0 + _Cis*cos2u0)*2*dotv;
double dotr = a0 * _e*sin(E) * dEdM * n
+ (-_Crc*sin2u0 + _Crs*cos2u0)*2*dotv;
double dotx = dotr*cos(u) - r*sin(u)*dotu;
double doty = dotr*sin(u) + r*cos(u)*dotu;
vv(1) = cosom *dotx - cosi*sinom *doty // dX / dr
- xp*sinom*dotom - yp*cosi*cosom*dotom // dX / dOMEGA
+ yp*sini*sinom*doti; // dX / di
vv(2) = sinom *dotx + cosi*cosom *doty
+ xp*cosom*dotom - yp*cosi*sinom*dotom
- yp*sini*cosom*doti;
vv(3) = sini *doty + yp*cosi *doti;
}
// Read Glonass Ephemeris
////////////////////////////////////////////////////////////////////////////
void t_ephGlo::read(const QStringList& lines) {
for (int ii = 1; ii <= lines.size(); ii++) {
QTextStream in(lines.at(ii-1).toAscii());
if (ii == 1) {
double year, month, day, hour, minute, second;
in >> _prn >> year >> month >> day >> hour >> minute >> second
>> _tau >> _gamma;
_tau = -_tau;
if (year < 100) year += 2000;
QDateTime dateTime(QDate(int(year), int(month), int(day)),
QTime(int(hour), int(minute), int(second)), Qt::UTC);
GPSweekFromDateAndTime(dateTime, _GPSweek, _GPSweeks);
//// beg test
//// _gps_utc = 14.0;
//// end test
_GPSweeks += _gps_utc;
}
else if (ii == 2) {
in >>_x_pos >> _x_velocity >> _x_acceleration >> _health;
}
else if (ii == 3) {
in >>_y_pos >> _y_velocity >> _y_acceleration >> _frequency_number;
}
else if (ii == 4) {
in >>_z_pos >> _z_velocity >> _z_acceleration >> _E;
}
}
// Initialize status vector
// ------------------------
_tt = _GPSweeks;
_xv(1) = _x_pos * 1.e3;
_xv(2) = _y_pos * 1.e3;
_xv(3) = _z_pos * 1.e3;
_xv(4) = _x_velocity * 1.e3;
_xv(5) = _y_velocity * 1.e3;
_xv(6) = _z_velocity * 1.e3;
}
// Derivative of the state vector using a simple force model (static)
////////////////////////////////////////////////////////////////////////////
ColumnVector t_ephGlo::glo_deriv(double /* tt */, const ColumnVector& xv) {
// State vector components
// -----------------------
ColumnVector rr = xv.rows(1,3);
ColumnVector vv = xv.rows(4,6);
// Acceleration
// ------------
const static double GM = 398.60044e12;
const static double AE = 6378136.0;
const static double OMEGA = 7292115.e-11;
const static double C20 = -1082.63e-6;
double rho = rr.norm_Frobenius();
double t1 = -GM/(rho*rho*rho);
double t2 = 3.0/2.0 * C20 * (GM*AE*AE) / (rho*rho*rho*rho*rho);
double t3 = OMEGA * OMEGA;
double t4 = 2.0 * OMEGA;
double z2 = rr(3) * rr(3);
// Vector of derivatives
// ---------------------
ColumnVector va(6);
va(1) = vv(1);
va(2) = vv(2);
va(3) = vv(3);
va(4) = (t1 + t2*(1.0-5.0*z2/(rho*rho)) + t3) * rr(1) + t4*vv(2);
va(5) = (t1 + t2*(1.0-5.0*z2/(rho*rho)) + t3) * rr(2) - t4*vv(1);
va(6) = (t1 + t2*(3.0-5.0*z2/(rho*rho)) ) * rr(3);
return va;
}
// Compute Glonass Satellite Position
////////////////////////////////////////////////////////////////////////////
void t_ephGlo::position(int GPSweek, double GPSweeks, ColumnVector& xc,
ColumnVector& vv) const {
const static double secPerWeek = 7 * 86400.0;
const static double nominalStep = 10.0;
double dtPos = GPSweeks - _tt;
if (GPSweek != _GPSweek) {
dtPos += (GPSweek - _GPSweek) * secPerWeek;
}
int nSteps = int(fabs(dtPos) / nominalStep) + 1;
double step = dtPos / nSteps;
for (int ii = 1; ii <= nSteps; ii++) {
_xv = rungeKutta4(_tt, _xv, step, glo_deriv);
_tt += step;
}
// Position and Velocity
// ---------------------
xc(1) = _xv(1);
xc(2) = _xv(2);
xc(3) = _xv(3);
vv(1) = _xv(4);
vv(2) = _xv(5);
vv(3) = _xv(6);
// Clock Correction
// ----------------
double dtClk = GPSweeks - _GPSweeks;
if (GPSweek != _GPSweek) {
dtClk += (GPSweek - _GPSweek) * secPerWeek;
}
xc(4) = -_tau + _gamma * dtClk;
}
// Glonass IOD
////////////////////////////////////////////////////////////////////////////
int t_ephGlo::IOD() const {
//// return int(fmod(_GPSweeks,86400.0)) / 600;
//// unsigned int tb = int(fmod(_GPSweeks,86400.0)) * 1000; // msec of day
unsigned int tb = int(fmod(_GPSweeks,86400.0)); //sec of day
// 5 LSBs of iod are equal to 5 LSBs of tb, remaining bits are zero
// ----------------------------------------------------------------
const int shift = sizeof(tb) * 8 - 5;
unsigned int iod = tb << shift;
return (iod >> shift);
}