TLEPropagatorBuilder.java
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package org.orekit.propagation.conversion;
import java.util.List;
import org.orekit.annotation.DefaultDataContext;
import org.orekit.attitudes.InertialProvider;
import org.orekit.data.DataContext;
import org.orekit.estimation.leastsquares.AbstractBatchLSModel;
import org.orekit.estimation.leastsquares.BatchLSModel;
import org.orekit.estimation.leastsquares.ModelObserver;
import org.orekit.estimation.measurements.ObservedMeasurement;
import org.orekit.estimation.sequential.AbstractKalmanModel;
import org.orekit.estimation.sequential.CovarianceMatrixProvider;
import org.orekit.estimation.sequential.KalmanModel;
import org.orekit.frames.Frame;
import org.orekit.orbits.Orbit;
import org.orekit.orbits.PositionAngle;
import org.orekit.propagation.Propagator;
import org.orekit.propagation.SpacecraftState;
import org.orekit.propagation.analytical.tle.TLE;
import org.orekit.propagation.analytical.tle.TLEPropagator;
import org.orekit.time.TimeScale;
import org.orekit.utils.ParameterDriver;
import org.orekit.utils.ParameterDriversList;
/** Builder for TLEPropagator.
* @author Pascal Parraud
* @author Thomas Paulet
* @since 6.0
*/
public class TLEPropagatorBuilder extends AbstractPropagatorBuilder implements OrbitDeterminationPropagatorBuilder {
/** Default value for epsilon. */
private static final double EPSILON_DEFAULT = 1.0e-10;
/** Default value for maxIterations. */
private static final int MAX_ITERATIONS_DEFAULT = 100;
/** Data context used to access frames and time scales. */
private final DataContext dataContext;
/** Template TLE. */
private final TLE templateTLE;
/** Threshold for convergence used in TLE generation. */
private final double epsilon;
/** Maximum number of iterations for convergence used in TLE generation. */
private final int maxIterations;
/** Build a new instance. This constructor uses the {@link DataContext#getDefault()
* default data context}.
* <p>
* The template TLE is used as a model to {@link
* #createInitialOrbit() create initial orbit}. It defines the
* inertial frame, the central attraction coefficient, orbit type, satellite number,
* classification, .... and is also used together with the {@code positionScale} to
* convert from the {@link ParameterDriver#setNormalizedValue(double) normalized}
* parameters used by the callers of this builder to the real orbital parameters.
* </p><p>
* Using this constructor, {@link #EPSILON_DEFAULT} and {@link #MAX_ITERATIONS_DEFAULT}
* are used for spacecraft's state to TLE transformation
* </p>
* @param templateTLE reference TLE from which real orbits will be built
* @param positionAngle position angle type to use
* @param positionScale scaling factor used for orbital parameters normalization
* (typically set to the expected standard deviation of the position)
* @since 7.1
* @see #TLEPropagatorBuilder(TLE, PositionAngle, double, DataContext)
*/
@DefaultDataContext
public TLEPropagatorBuilder(final TLE templateTLE, final PositionAngle positionAngle,
final double positionScale) {
this(templateTLE, positionAngle, positionScale, DataContext.getDefault());
}
/** Build a new instance.
* <p>
* The template TLE is used as a model to {@link
* #createInitialOrbit() create initial orbit}. It defines the
* inertial frame, the central attraction coefficient, orbit type, satellite number,
* classification, .... and is also used together with the {@code positionScale} to
* convert from the {@link ParameterDriver#setNormalizedValue(double) normalized}
* parameters used by the callers of this builder to the real orbital parameters.
* </p><p>
* Using this constructor, {@link #EPSILON_DEFAULT} and {@link #MAX_ITERATIONS_DEFAULT}
* are used for spacecraft's state to TLE transformation
* </p>
* @param templateTLE reference TLE from which real orbits will be built
* @param positionAngle position angle type to use
* @param positionScale scaling factor used for orbital parameters normalization
* (typically set to the expected standard deviation of the position)
* @param dataContext used to access frames and time scales.
* @since 10.1
* @see #TLEPropagatorBuilder(TLE, PositionAngle, double, DataContext, double, int)
*/
public TLEPropagatorBuilder(final TLE templateTLE,
final PositionAngle positionAngle,
final double positionScale,
final DataContext dataContext) {
this(templateTLE, positionAngle, positionScale, dataContext, EPSILON_DEFAULT, MAX_ITERATIONS_DEFAULT);
}
/** Build a new instance. This constructor uses the {@link DataContext#getDefault()
* default data context}.
* <p>
* The template TLE is used as a model to {@link
* #createInitialOrbit() create initial orbit}. It defines the
* inertial frame, the central attraction coefficient, orbit type, satellite number,
* classification, .... and is also used together with the {@code positionScale} to
* convert from the {@link ParameterDriver#setNormalizedValue(double) normalized}
* parameters used by the callers of this builder to the real orbital parameters.
* </p>
* @param templateTLE reference TLE from which real orbits will be built
* @param positionAngle position angle type to use
* @param positionScale scaling factor used for orbital parameters normalization
* (typically set to the expected standard deviation of the position)
* @param epsilon used to compute threshold for convergence check
* @param maxIterations maximum number of iterations for convergence
* @since 11.0.2
* @see #TLEPropagatorBuilder(TLE, PositionAngle, double, DataContext, double, int)
*/
@DefaultDataContext
public TLEPropagatorBuilder(final TLE templateTLE, final PositionAngle positionAngle,
final double positionScale, final double epsilon,
final int maxIterations) {
this(templateTLE, positionAngle, positionScale, DataContext.getDefault(), epsilon, maxIterations);
}
/** Build a new instance.
* <p>
* The template TLE is used as a model to {@link
* #createInitialOrbit() create initial orbit}. It defines the
* inertial frame, the central attraction coefficient, orbit type, satellite number,
* classification, .... and is also used together with the {@code positionScale} to
* convert from the {@link ParameterDriver#setNormalizedValue(double) normalized}
* parameters used by the callers of this builder to the real orbital parameters.
* </p>
* @param templateTLE reference TLE from which real orbits will be built
* @param positionAngle position angle type to use
* @param positionScale scaling factor used for orbital parameters normalization
* (typically set to the expected standard deviation of the position)
* @param dataContext used to access frames and time scales.
* @param epsilon used to compute threshold for convergence check
* @param maxIterations maximum number of iterations for convergence
* @since 11.0.2
*/
public TLEPropagatorBuilder(final TLE templateTLE,
final PositionAngle positionAngle,
final double positionScale,
final DataContext dataContext,
final double epsilon,
final int maxIterations) {
super(TLEPropagator.selectExtrapolator(templateTLE, dataContext.getFrames())
.getInitialState().getOrbit(),
positionAngle, positionScale, false,
InertialProvider.of(dataContext.getFrames().getTEME()));
for (final ParameterDriver driver : templateTLE.getParametersDrivers()) {
addSupportedParameter(driver);
}
this.templateTLE = templateTLE;
this.dataContext = dataContext;
this.epsilon = epsilon;
this.maxIterations = maxIterations;
}
/** {@inheritDoc} */
@Override
public TLEPropagator buildPropagator(final double[] normalizedParameters) {
// create the orbit
setParameters(normalizedParameters);
final Orbit orbit = createInitialOrbit();
final SpacecraftState state = new SpacecraftState(orbit);
final Frame teme = dataContext.getFrames().getTEME();
final TimeScale utc = dataContext.getTimeScales().getUTC();
// TLE related to the orbit
final TLE tle = TLE.stateToTLE(state, templateTLE, utc, teme, epsilon, maxIterations);
final List<ParameterDriver> drivers = templateTLE.getParametersDrivers();
for (int index = 0; index < drivers.size(); index++) {
if (drivers.get(index).isSelected()) {
tle.getParametersDrivers().get(index).setSelected(true);
}
}
// propagator
return TLEPropagator.selectExtrapolator(tle,
getAttitudeProvider(),
Propagator.DEFAULT_MASS,
teme);
}
/** Getter for the template TLE.
* @return the template TLE
*/
public TLE getTemplateTLE() {
return templateTLE;
}
/** {@inheritDoc} */
public AbstractBatchLSModel buildLSModel(final OrbitDeterminationPropagatorBuilder[] builders,
final List<ObservedMeasurement<?>> measurements,
final ParameterDriversList estimatedMeasurementsParameters,
final ModelObserver observer) {
return new BatchLSModel(builders, measurements, estimatedMeasurementsParameters, observer);
}
@Override
public AbstractKalmanModel
buildKalmanModel(final List<OrbitDeterminationPropagatorBuilder> propagatorBuilders,
final List<CovarianceMatrixProvider> covarianceMatricesProviders,
final ParameterDriversList estimatedMeasurementsParameters,
final CovarianceMatrixProvider measurementProcessNoiseMatrix) {
return new KalmanModel(propagatorBuilders, covarianceMatricesProviders, estimatedMeasurementsParameters, measurementProcessNoiseMatrix);
}
}