Hi @bcazabonne , I have a doubt, that I would like to clarify:
With the Batch-type filters, at what state estimated, does the covariance matrix refer to?
I mean the covariance matrix that I get with:
covMat_eci_java = estimator.getPhysicalCovariances(1.0e-10)
I mean this: let’s say I have this scenario:
t1 = start of measurements and start of OD
t2 = end of measurements (but NOT end of OD propagation)
t3 = end of OD propagation
What point does the covacity matrix refer to?
t1, t2, t3, an average of all the points, … ?
Many thanks for your time and help
Kind Regards
Alessandro
This is an excerpt of the code
set estimator
matrix_decomposer = QRDecomposer(1e-11)
optimizer = GaussNewtonOptimizer(matrix_decomposer, False)
estimator = BatchLSEstimator(optimizer, propagatorBuilder)
estimator.setParametersConvergenceThreshold(estimator_convergence_thres)
estimator.setMaxIterations(estimator_max_iterations)
estimator.setMaxEvaluations(estimator_max_evaluations)
observableSatellite = ObservableSatellite(0) # Propagator index = 0
Performing the orbit determination
estimatedPropagatorArray = estimator.estimate()
date_start = datetime_to_absolutedate(posMeas_df_pack.index[0]) # start meas and OD
date_end = datetime_to_absolutedate(posMeas_df_pack.index[-1] + timedelta(seconds= timePropAfterMeas )) end of OD propagation
#Note: datetime_to_absolutedate(posMeas_df_pack.index[-1]) is the time of end meas
First propagating in ephemeris mode
estimatedPropagator = estimatedPropagatorArray[0]
estimatedInitialState = estimatedPropagator.getInitialState()
estimatedPropagator.resetInitialState(estimatedInitialState)
generator = estimatedPropagator.getEphemerisGenerator();
estimatedPropagator.propagate(date_start, date_end);
bounded_propagator = generator.getGeneratedEphemeris();
Getting covariance matrix in ECI frame
covMat_eci_java = estimator.getPhysicalCovariances(1.0e-10)