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sdrangel/plugins/feature/satellitetracker/satellitetrackersgp4.cpp
Jon Beniston 04aed0b3b3 Satellite Tracker updates.
Add support for replaying of passes in the past, where current time is
determined from File Input device.
Add latitude and longitude to satellite data table.
Update ground track generation to better work with 3D map.
Add support for 3D models.
Add Cubesat image for 2D map.
Send LOS to other plugins, when no device settings are setup.
Pass TLEs to other plugins, so they can use a consistent copy for
replays.
2022-02-04 17:14:12 +00:00

532 lines
20 KiB
C++

///////////////////////////////////////////////////////////////////////////////////
// Copyright (C) 2021 Jon Beniston, M7RCE //
// Copyright (C) 2013 Daniel Warner <contact@danrw.com> //
// //
// 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 as version 3 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 V3 for more details. //
// //
// You should have received a copy of the GNU General Public License //
// along with this program. If not, see <http://www.gnu.org/licenses/>. //
///////////////////////////////////////////////////////////////////////////////////
#include <cmath>
#include <CoordTopocentric.h>
#include <CoordGeodetic.h>
#include <Observer.h>
#include <SGP4.h>
#include "util/units.h"
#include "satellitetrackersgp4.h"
// Convert QGP4 DateTime to Qt QDataTime
static QDateTime dateTimeToQDateTime(DateTime dt)
{
QDateTime qdt(QDate(dt.Year(), dt.Month(), dt.Day()), QTime(dt.Hour(), dt.Minute(), dt.Second(), (int)(dt.Microsecond()/1000.0)), Qt::UTC);
return qdt;
}
// Convert Qt QDataTime to QGP4 DateTime
static DateTime qDateTimeToDateTime(QDateTime qdt)
{
QDateTime utc = qdt.toUTC();
QDate date = utc.date();
QTime time = utc.time();
DateTime dt;
dt.Initialise(date.year(), date.month(), date.day(), time.hour(), time.minute(), time.second(), time.msec() * 1000);
return dt;
}
// Get ground track
// Throws SatelliteException, DecayedException and TleException
void getGroundTrack(QDateTime dateTime,
const QString& tle0, const QString& tle1, const QString& tle2,
int steps, bool forward,
QList<QGeoCoordinate *>& coordinates,
QList<QDateTime *>& coordinateDateTimes)
{
Tle tle = Tle(tle0.toStdString(), tle1.toStdString(), tle2.toStdString());
SGP4 sgp4(tle);
OrbitalElements ele(tle);
double periodMins;
double timeStep;
// For 3D map, we want to quantize to minutes, so we replace previous
// position data, rather than insert additional positions alongside the old
// which can result is the camera view jumping around
dateTime = QDateTime(dateTime.date(), QTime(dateTime.time().hour(), dateTime.time().minute()));
// Note 2D map doesn't support paths wrapping around Earth several times
// So we just have a slight overlap here, with the future track being longer
DateTime currentTime = qDateTimeToDateTime(dateTime);
DateTime endTime;
if (forward)
{
periodMins = ele.Period() * 0.9;
endTime = currentTime.AddMinutes(periodMins);
timeStep = periodMins / (steps * 0.9);
}
else
{
periodMins = ele.Period() * 0.4;
endTime = currentTime.AddMinutes(-periodMins);
timeStep = -periodMins / (steps * 0.4);
}
// Quantize time step to 30 seconds
timeStep *= 2.0;
if (timeStep > 0.0) {
timeStep = std::max(timeStep, 1.0);
} else if (timeStep < 0.0) {
timeStep = std::min(timeStep, -1.0);
}
timeStep = round(timeStep);
timeStep /= 2.0;
while ((forward && (currentTime < endTime)) || (!forward && (currentTime > endTime)))
{
// Calculate satellite position
Eci eci = sgp4.FindPosition(currentTime);
// Convert satellite position to geodetic coordinates (lat and long)
CoordGeodetic geo = eci.ToGeodetic();
QGeoCoordinate *coord = new QGeoCoordinate(Units::radiansToDegrees(geo.latitude),
Units::radiansToDegrees(geo.longitude),
geo.altitude * 1000.0);
coordinates.append(coord);
QDateTime *coordDateTime = new QDateTime(dateTimeToQDateTime(currentTime));
coordinateDateTimes.append(coordDateTime);
// 2D map is stretched at poles, so use finer steps
if (std::abs(Units::radiansToDegrees(geo.latitude)) >= 70)
currentTime = currentTime.AddMinutes(timeStep/4);
else
currentTime = currentTime.AddMinutes(timeStep);
}
}
// Find azimuth and elevation points during a pass
void getPassAzEl(QLineSeries* azimuth, QLineSeries* elevation, QLineSeries* polar,
const QString& tle0, const QString& tle1, const QString& tle2,
double latitude, double longitude, double altitude,
QDateTime& aos, QDateTime& los)
{
try
{
Tle tle = Tle(tle0.toStdString(), tle1.toStdString(), tle2.toStdString());
SGP4 sgp4(tle);
Observer obs(latitude, longitude, altitude);
DateTime aosTime = qDateTimeToDateTime(aos);
DateTime losTime = qDateTimeToDateTime(los);
DateTime currentTime(aosTime);
int steps = 20;
double timeStep = (losTime - aosTime).TotalSeconds() / steps;
if (timeStep <= 0.0)
{
qDebug() << "getPassAzEl: AOS is the same as or after LOS";
return;
}
while (currentTime <= losTime)
{
// Calculate satellite position
Eci eci = sgp4.FindPosition(currentTime);
// Calculate angle to satellite from antenna
CoordTopocentric topo = obs.GetLookAngle(eci);
// Save azimuth and elevation in series
QDateTime qdt = dateTimeToQDateTime(currentTime);
if (azimuth != nullptr)
azimuth->append(qdt.toMSecsSinceEpoch(), Units::radiansToDegrees(topo.azimuth));
if (elevation != nullptr)
elevation->append(qdt.toMSecsSinceEpoch(), Units::radiansToDegrees(topo.elevation));
if (polar != nullptr)
polar->append(Units::radiansToDegrees(topo.azimuth), 90.0-Units::radiansToDegrees(topo.elevation));
currentTime = currentTime.AddSeconds(timeStep);
}
}
catch (SatelliteException& se)
{
qDebug() << se.what();
}
catch (DecayedException& de)
{
qDebug() << de.what();
}
catch (TleException& tlee)
{
qDebug() << tlee.what();
}
}
// Get whether a pass passes through 0 degreees
bool getPassesThrough0Deg(const QString& tle0, const QString& tle1, const QString& tle2,
double latitude, double longitude, double altitude,
QDateTime& aos, QDateTime& los)
{
try
{
Tle tle = Tle(tle0.toStdString(), tle1.toStdString(), tle2.toStdString());
SGP4 sgp4(tle);
Observer obs(latitude, longitude, altitude);
DateTime aosTime = qDateTimeToDateTime(aos);
DateTime losTime = qDateTimeToDateTime(los);
DateTime currentTime(aosTime);
int steps = 20;
double timeStep = (losTime - aosTime).TotalSeconds() / steps;
double prevAz;
for (int i = 0; i < steps; i++)
{
// Calculate satellite position
Eci eci = sgp4.FindPosition(currentTime);
// Calculate angle to satellite from antenna
CoordTopocentric topo = obs.GetLookAngle(eci);
double az = Units::radiansToDegrees(topo.azimuth);
if (i == 0)
prevAz = az;
// Does it cross 0 degrees?
if (((prevAz > 270.0) && (az < 90.0)) || ((prevAz < 90.0) && (az >= 270.0)))
return true;
prevAz = az;
currentTime = currentTime.AddSeconds(timeStep);
}
}
catch (SatelliteException& se)
{
qDebug() << se.what();
}
catch (DecayedException& de)
{
qDebug() << de.what();
}
catch (TleException& tlee)
{
qDebug() << tlee.what();
}
return false;
}
// Find maximum elevation in a pass
static double findMaxElevation(Observer& obs1, SGP4& sgp4, const DateTime& aos, const DateTime& los)
{
Observer obs(obs1.GetLocation());
bool running;
double timeStep = (los - aos).TotalSeconds() / 9.0;
DateTime currentTime(aos);
DateTime time1(aos);
DateTime time2(los);
double maxElevation;
do
{
running = true;
maxElevation = -INFINITY;
while (running && (currentTime < time2))
{
Eci eci = sgp4.FindPosition(currentTime);
CoordTopocentric topo = obs.GetLookAngle(eci);
if (topo.elevation > maxElevation)
{
maxElevation = topo.elevation;
currentTime = currentTime.AddSeconds(timeStep);
if (currentTime > time2)
currentTime = time2;
}
else
running = false;
}
time1 = currentTime.AddSeconds(-2.0 * timeStep);
time2 = currentTime;
currentTime = time1;
timeStep = (time2 - time1).TotalSeconds() / 9.0;
}
while (timeStep > 1.0);
return Units::radiansToDegrees(maxElevation);
}
// Find the time at which the satellite crossed the minimum elevation required for AOS or LOS
static DateTime findCrossingPoint(Observer& obs, SGP4& sgp4, const DateTime& initialTime1, const DateTime& initialTime2, double minElevation, bool findingAOS)
{
bool running;
int cnt;
DateTime time1(initialTime1);
DateTime time2(initialTime2);
DateTime middleTime;
running = true;
cnt = 0;
while (running && (cnt++ < 16))
{
middleTime = time1.AddSeconds((time2 - time1).TotalSeconds() / 2.0);
Eci eci = sgp4.FindPosition(middleTime);
CoordTopocentric topo = obs.GetLookAngle(eci);
if (topo.elevation > minElevation)
{
if (findingAOS)
time2 = middleTime;
else
time1 = middleTime;
}
else
{
if (findingAOS)
time1 = middleTime;
else
time2 = middleTime;
}
if ((time2 - time1).TotalSeconds() < 1.0)
{
running = false;
int us = middleTime.Microsecond();
middleTime = middleTime.AddMicroseconds(-us);
middleTime = middleTime.AddSeconds(findingAOS ? 1 : -1);
}
}
running = true;
cnt = 0;
while (running && (cnt++ < 6))
{
Eci eci = sgp4.FindPosition(middleTime);
CoordTopocentric topo = obs.GetLookAngle(eci);
if (topo.elevation > minElevation)
middleTime = middleTime.AddSeconds(findingAOS ? -1 : 1);
else
running = false;
}
return middleTime;
}
// Find when AOS occured, by stepping backwards
static DateTime findAOSBackwards(Observer& obs, SGP4& sgp4, DateTime& startTime,
int predictionPeriod, double minElevation, bool& aosUnknown)
{
DateTime previousTime(startTime);
DateTime currentTime(startTime);
DateTime endTime(startTime.AddDays(-predictionPeriod));
while (currentTime >= endTime)
{
Eci eci = sgp4.FindPosition(currentTime);
CoordTopocentric topo = obs.GetLookAngle(eci);
if (topo.elevation < minElevation)
{
aosUnknown = false;
return findCrossingPoint(obs, sgp4, currentTime, previousTime, minElevation, true);
}
previousTime = currentTime;
currentTime = currentTime - TimeSpan(0, 0, 180);
}
aosUnknown = true;
return currentTime;
}
bool inPassWindow(DateTime dateTime, QTime passStartTime, QTime passEndTime, bool utc)
{
// Don't compare seconds as not currently settable in GUI
QDateTime qdt = dateTimeToQDateTime(dateTime);
if (!utc)
qdt = qdt.toLocalTime();
QTime qt(qdt.time().hour(), qdt.time().minute());
passStartTime = QTime(passStartTime.hour(), passStartTime.minute());
passEndTime = QTime(passEndTime.hour(), passEndTime.minute());
// If passEndTime is before passStartTime, then we allow overnight passes
if (passEndTime > passStartTime)
{
return (qt >= passStartTime) && (qt <= passEndTime);
}
else
{
return (qt <= passEndTime) || (qt >= passStartTime);
}
}
// Create a list of satellite passes, between the given start and end times, that exceed the specified minimum elevation
// We return an uninitalised QDateTime if AOS or LOS is outside of predictionPeriod
static QList<SatellitePass *> createPassList(Observer& obs, SGP4& sgp4, DateTime& startTime,
int predictionPeriod, double minAOSElevation, double minPassElevationDeg,
QTime passStartTime, QTime passEndTime, bool utc,
int noOfPasses)
{
QList<SatellitePass *> passes;
bool aos = false;
bool aosUnknown = true;
double aosAz;
double losAz;
DateTime previousTime(startTime);
DateTime currentTime(startTime);
DateTime endTime(startTime.AddDays(predictionPeriod));
DateTime aosTime;
DateTime losTime;
while (currentTime < endTime)
{
bool endOfPass = false;
Eci eci = sgp4.FindPosition(currentTime);
CoordTopocentric topo = obs.GetLookAngle(eci);
if (!aos && (topo.elevation > minAOSElevation))
{
if (startTime == currentTime)
{
// AOS is before startTime
aosTime = findAOSBackwards(obs, sgp4, startTime, predictionPeriod, minAOSElevation, aosUnknown);
}
else
{
aosTime = findCrossingPoint(obs, sgp4, previousTime, currentTime, minAOSElevation, true);
aosUnknown = false;
}
aos = true;
eci = sgp4.FindPosition(aosTime);
topo = obs.GetLookAngle(eci);
aosAz = Units::radiansToDegrees(topo.azimuth);
}
else if (aos && (topo.elevation < minAOSElevation))
{
aos = false;
endOfPass = true;
losTime = findCrossingPoint(obs, sgp4, previousTime, currentTime, minAOSElevation, false);
eci = sgp4.FindPosition(losTime);
topo = obs.GetLookAngle(eci);
losAz = Units::radiansToDegrees(topo.azimuth);
double maxElevationDeg = findMaxElevation(obs, sgp4, aosTime, losTime);
if ((maxElevationDeg >= minPassElevationDeg)
&& inPassWindow(aosTime, passStartTime, passEndTime, utc)
&& inPassWindow(losTime, passStartTime, passEndTime, utc))
{
SatellitePass *pass = new SatellitePass;
pass->m_aos = aosUnknown ? QDateTime() : dateTimeToQDateTime(aosTime);
pass->m_los = dateTimeToQDateTime(losTime);
pass->m_maxElevation = maxElevationDeg;
pass->m_aosAzimuth = aosAz;
pass->m_losAzimuth = losAz;
pass->m_northToSouth = std::min(360.0-aosAz, aosAz-0.0) < std::min(360.0-losAz, losAz-0.0);
passes.append(pass);
noOfPasses--;
if (noOfPasses <= 0)
return passes;
}
}
previousTime = currentTime;
if (endOfPass)
currentTime = currentTime + TimeSpan(0, 30, 0); // 30 minutes - no orbit likely to be that fast
else
currentTime = currentTime + TimeSpan(0, 0, 180);
if (currentTime > endTime)
currentTime = endTime;
}
if (aos)
{
// Pass still in progress at end time
Eci eci = sgp4.FindPosition(currentTime);
CoordTopocentric topo = obs.GetLookAngle(eci);
losAz = Units::radiansToDegrees(topo.azimuth);
double maxElevationDeg = findMaxElevation(obs, sgp4, aosTime, losTime);
if ((maxElevationDeg >= minPassElevationDeg)
&& inPassWindow(aosTime, passStartTime, passEndTime, utc)
&& inPassWindow(losTime, passStartTime, passEndTime, utc))
{
SatellitePass *pass = new SatellitePass;
pass->m_aos = aosUnknown ? QDateTime() : dateTimeToQDateTime(aosTime);
pass->m_los = QDateTime();
pass->m_aosAzimuth = aosAz;
pass->m_losAzimuth = losAz;
pass->m_maxElevation = maxElevationDeg;
pass->m_northToSouth = std::min(360.0-aosAz, aosAz-0.0) < std::min(360.0-losAz, losAz-0.0);
passes.append(pass);
}
}
return passes;
}
void getSatelliteState(QDateTime dateTime,
const QString& tle0, const QString& tle1, const QString& tle2,
double latitude, double longitude, double altitude,
int predictionPeriod, int minAOSElevationDeg, int minPassElevationDeg,
QTime passStartTime, QTime passFinishTime, bool utc,
int noOfPasses, int groundTrackSteps, SatelliteState *satState)
{
try {
Tle tle = Tle(tle0.toStdString(), tle1.toStdString(), tle2.toStdString());
SGP4 sgp4(tle);
Observer obs(latitude, longitude, altitude);
DateTime dt = qDateTimeToDateTime(dateTime);
// Calculate satellite position
Eci eci = sgp4.FindPosition(dt);
// Calculate angle to satellite from antenna
CoordTopocentric topo = obs.GetLookAngle(eci);
// Convert satellite position to geodetic coordinates (lat and long)
CoordGeodetic geo = eci.ToGeodetic();
satState->m_latitude = Units::radiansToDegrees(geo.latitude);
satState->m_longitude = Units::radiansToDegrees(geo.longitude);
satState->m_altitude = geo.altitude;
satState->m_azimuth = Units::radiansToDegrees(topo.azimuth);
satState->m_elevation = Units::radiansToDegrees(topo.elevation);
satState->m_range = topo.range;
satState->m_rangeRate = topo.range_rate;
OrbitalElements ele(tle);
satState->m_speed = eci.Velocity().Magnitude();
satState->m_period = ele.Period();
if (noOfPasses > 0)
{
qDeleteAll(satState->m_passes);
satState->m_passes = createPassList(obs, sgp4, dt, predictionPeriod,
Units::degreesToRadians((double)minAOSElevationDeg),
minPassElevationDeg,
passStartTime, passFinishTime, utc,
noOfPasses);
}
qDeleteAll(satState->m_groundTrack);
satState->m_groundTrack.clear();
qDeleteAll(satState->m_groundTrackDateTime);
satState->m_groundTrackDateTime.clear();
qDeleteAll(satState->m_predictedGroundTrack);
satState->m_predictedGroundTrack.clear();
qDeleteAll(satState->m_predictedGroundTrackDateTime);
satState->m_predictedGroundTrackDateTime.clear();
getGroundTrack(dateTime, tle0, tle1, tle2, groundTrackSteps, false, satState->m_groundTrack, satState->m_groundTrackDateTime);
getGroundTrack(dateTime, tle0, tle1, tle2, groundTrackSteps, true, satState->m_predictedGroundTrack, satState->m_predictedGroundTrackDateTime);
}
catch (SatelliteException& se)
{
qDebug() << "getSatelliteState: " << satState->m_name << ": " << se.what();
}
catch (DecayedException& de)
{
qDebug() << "getSatelliteState: " << satState->m_name << ": " << de.what();
}
catch (TleException& tlee)
{
qDebug() << "getSatelliteState: " << satState->m_name << ": " << tlee.what();
}
}