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/***********************************************/
/**
* @file observationPodAcceleration.cpp
*
* @brief Precise Orbit Data (POD) observations (Acceleration approach).
*
* @author Torsten Mayer-Guerr
* @date 2006-02-02
* update 2011-06-09 Norbert Zehentner
*
*/
/***********************************************/
#include "base/import.h"
#include "parallel/parallel.h"
#include "files/fileInstrument.h"
#include "files/fileSatelliteModel.h"
#include "misc/observation/observationMisc.h"
#include "classes/earthRotation/earthRotation.h"
#include "classes/parametrizationGravity/parametrizationGravity.h"
#include "classes/parametrizationAcceleration/parametrizationAcceleration.h"
#include "classes/observation/observation.h"
#include "classes/observation/observationPodAcceleration.h"
/***********************************************/
ObservationPodAcceleration::ObservationPodAcceleration(Config &config)
{
try
{
FileName fileNameSatellite;
FileName orbitName, starCameraName;
UInt epochCount, interpolationDegree;
renameDeprecatedConfig(config, "satelliteModel", "inputfileSatelliteModel", date2time(2020, 8, 19));
renameDeprecatedConfig(config, "representation", "parametrizationGravity", date2time(2020, 6, 3));
renameDeprecatedConfig(config, "parameter", "parametrizationAcceleration", date2time(2020, 6, 3));
readConfig(config, "inputfileSatelliteModel", fileNameSatellite, Config::OPTIONAL, "{groopsDataDir}/satelliteModel/", "satellite macro model");
readConfig(config, "rightHandSide", rhs, Config::MUSTSET, "", "input for the reduced observation vector");
readConfig(config, "inputfileOrbit", orbitName, Config::MUSTSET, "", "used to evaluate the observation equations, not used as observations");
readConfig(config, "inputfileStarCamera", starCameraName, Config::MUSTSET, "", "");
readConfig(config, "earthRotation", earthRotation, Config::MUSTSET, "", "");
readConfig(config, "ephemerides", ephemerides, Config::OPTIONAL, "jpl", "");
readConfig(config, "parametrizationGravity", parametrization, Config::MUSTSET, "", "gravity field parametrization");
readConfig(config, "parametrizationAcceleration", parametrizationAcceleration, Config::DEFAULT, "", "orbit force parameters");
readConfig(config, "interpolationDegree", interpolationDegree, Config::DEFAULT, "8", "orbit differentation by polynomial approximation of degree n");
readConfig(config, "numberOfEpochs", epochCount, Config::DEFAULT, "9", "number of used Epochs for polynom computation");
readConfig(config, "covariancePod", covPod, Config::OPTIONAL, "", "covariance matrix of kinematic orbits");
if(isCreateSchema(config)) return;
// test if epochCount and polynomial degree are correct
// ---------------------
if(interpolationDegree%2 != 0)
throw(Exception("polnomial degree for interpolation must be even."));
if(epochCount <= interpolationDegree)
throw(Exception("Epochs must be greater than interpolationdegree, at least by one."));
if(epochCount%2 != 1)
throw(Exception("Epochs must be odd (symmetry around central point)."));
if(!fileNameSatellite.empty())
readFileSatelliteModel(fileNameSatellite, satellite);
// test instrument files
// ---------------------
orbitFile.open(orbitName);
starCameraFile.open(starCameraName);
InstrumentFile::checkArcCount({orbitFile, starCameraFile});
for(UInt j=0; j<rhs.size(); j++)
InstrumentFile::checkArcCount({orbitFile, *rhs.at(j)->orbitFile, *rhs.at(j)->accelerometerFile});
// orbit differentation coefficients (position -> acceleration) by means of QR-decomposition
// with or without overdetermination
// -----------------------
Matrix P(epochCount, interpolationDegree+1);
for(UInt i=0; i<epochCount; i++)
for(UInt n=0; n<=interpolationDegree; n++)
P(i,n) = ((n==0) ? 1.0 : std::pow(i-(epochCount-1.)/2., n));
const Vector tau = QR_decomposition(P);
coeff = Vector(epochCount);
coeff(2) = 2.0;
triangularSolve(1., P.row(0,interpolationDegree+1).trans(), coeff);
QMult(P, tau, coeff);
}
catch(std::exception &e)
{
GROOPS_RETHROW(e)
}
}
/***********************************************/
Bool ObservationPodAcceleration::setInterval(const Time &timeStart, const Time &timeEnd)
{
try
{
Bool change = FALSE;
change = parametrization->setInterval(timeStart, timeEnd) || change;
change = parametrizationAcceleration->setInterval(timeStart, timeEnd) || change;
return change;
}
catch(std::exception &e)
{
GROOPS_RETHROW(e)
}
}
/***********************************************/
UInt ObservationPodAcceleration::parameterCount() const
{
return parametrization->parameterCount() + parametrizationAcceleration->parameterCount();
}
/***********************************************/
void ObservationPodAcceleration::parameterName(std::vector<ParameterName> &name) const
{
if(parametrization)
parametrization->parameterName(name);
if(parametrizationAcceleration)
{
parametrizationAcceleration->parameterName(name);
const std::string satelliteName = satellite ? satellite->satelliteName : "satellite";
for(UInt i=name.size(); i-->name.size()-parametrizationAcceleration->parameterCount();)
name.at(i).object = satelliteName;
}
}
/***********************************************/
void ObservationPodAcceleration::observation(UInt arcNo, Matrix &l, Matrix &A, Matrix &B)
{
try
{
OrbitArc orbit = orbitFile.readArc(arcNo);
StarCameraArc starCamera = starCameraFile.readArc(arcNo);
UInt rhsCount = rhs.size();
UInt posCount = orbit.size();
UInt obsCount = posCount-coeff.rows()+1;
UInt half = (coeff.rows()-1)/2;
Double dt = medianSampling(orbit.times()).seconds();
Arc::checkSynchronized({orbit, starCamera});
parametrizationAcceleration->setIntervalArc(orbit.at(half).time, orbit.at(obsCount+half-1).time+seconds2time(dt));
// calculate earthrotation
// -----------------------
std::vector<Rotary3d> rotEarth(obsCount);
for(UInt k=0; k<obsCount; k++)
rotEarth.at(k) = earthRotation->rotaryMatrix(orbit.at(k+half).time);
// reference acceleration
// ----------------------
std::vector<std::vector<Vector3d>> reference(rhsCount);
for(UInt j=0; j<rhsCount; j++)
{
reference.at(j).resize(obsCount);
AccelerometerArc accelerometer = rhs.at(j)->accelerometerFile->readArc(arcNo);
Arc::checkSynchronized({orbit, accelerometer});
for(UInt k=0; k<obsCount; k++)
{
Vector3d g = rhs.at(j)->forces->acceleration(satellite, orbit.at(k+half).time, orbit.at(k+half).position, orbit.at(k+half).velocity,
starCamera.at(k+half).rotary, rotEarth.at(k), earthRotation, ephemerides);
if(accelerometer.size())
g += rotEarth.at(k).rotate(starCamera.at(k+half).rotary.rotate(accelerometer.at(k+half).acceleration)); // accelerometer
reference.at(j).at(k) = g; // reference observations
}
}
// reduced observations
// --------------------
l = Matrix(3*obsCount, rhsCount);
for(UInt j=0; j<rhsCount; j++)
{
OrbitArc orbitPod = rhs.at(j)->orbitFile->readArc(arcNo);
for(UInt k=0; k<obsCount; k++)
{
Vector3d a;
for(UInt i=0; i<coeff.rows(); i++)
a += (coeff(i)/dt/dt) * orbitPod.at(k+i).position;
a = rotEarth.at(k).rotate(a);
l(3*k+0,j) = a.x() - reference.at(j).at(k).x();
l(3*k+1,j) = a.y() - reference.at(j).at(k).y();
l(3*k+2,j) = a.z() - reference.at(j).at(k).z();
}
}
// Design matrix A and B
// ---------------------
A = Matrix(3*obsCount, parametrization->parameterCount() + parametrizationAcceleration->parameterCount());
B = Matrix(3*obsCount, parametrizationAcceleration->parameterCountArc());
// gravity
for(UInt k=0; k<obsCount; k++)
parametrization->gravity(orbit.at(k+half).time, rotEarth.at(k).rotate(orbit.at(k+half).position), A.slice(3*k, 0, 3, parametrization->parameterCount()));
// orbit parameters
for(UInt k=0; k<obsCount; k++)
{
parametrizationAcceleration->compute(satellite, orbit.at(k+half).time, orbit.at(k+half).position, orbit.at(k+half).velocity,
starCamera.at(k+half).rotary, rotEarth.at(k), ephemerides,
A.slice(3*k, parametrization->parameterCount(), 3, parametrizationAcceleration->parameterCount()), B.row(3*k,3));
}
// decorrelation
// -------------
if(covPod)
{
// linearized variance propagation
Matrix D(3*obsCount, 3*posCount);
for(UInt k=0; k<obsCount; k++)
for(UInt i=0; i<coeff.rows(); i++)
axpy((coeff(i)/dt/dt), rotEarth.at(k).matrix(), D.slice(3*k,3*(k+i),3,3));
Matrix C = covPod->covariance(arcNo, orbit);
Matrix DCD = D * C * D.trans();
DCD.setType(Matrix::SYMMETRIC);
cholesky(DCD);
// apply Cholesky matrix
triangularSolve(1., DCD.trans(), A);
triangularSolve(1., DCD.trans(), l);
if(B.size())
triangularSolve(1., DCD.trans(), B);
}
}
catch(std::exception &e)
{
GROOPS_RETHROW(e)
}
}
/***********************************************/
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