Hi everyone,

I try to get the innovation from a `KalmanEstimator`

object. I use the `KalmanObserver`

interface as mentioned in this topic1 but it seems that the method `evaluationPerformed`

is not called. Bellow an example:

```
#My Kalman Observer class
class MyObserverTest(KalmanObserver):
def __init__(self):
pass
def evaluationPerformed(self, estimation):
print('step')
# Setting up the estimator
kalman_estimator_builder = KalmanEstimatorBuilder()
kalman_estimator_builder.addPropagationConfiguration(numerical_propagator_builder,ConstantProcessNoise(Q, initial_covariance_matrix))
kalman_estimator = kalman_estimator_builder.build()
#Adding the observer
my_observer_test = MyObserverTest()
kalman_estimator.setObserver(my_observer_test)
for spacecraft_state in list_spacecraft_state:
#Creating the measurement from the spacecraft state
date = spacecraft_state.getDate()
pv_coordinates = spacecraft_state.getPVCoordinates()
position = pv_coordinates.getPosition()
velocity = pv_coordinates.getVelocity()
pv_measurement = PV(date, position, velocity, sigma_pv, base_weight, obs_satellite)
#Estimation step
propagator_estimated = kalman_estimator.estimationStep(pv_measurement)[0]
#Testing the estimation
print(kalman_estimator.getPhysicalEstimatedCovarianceMatrix())
```

It only prints the covariance matrix but not the ‘step’ string from the `evaluationPerformed`

method.

Do you have any idea where the error is ?

Otherwise I have a doubt an another issue. When I use a `NumericalPropagatorBuilder`

in the `KalmanEstimatorBuilder`

it rises me the error of negative eccentricity for some initial state during the estimation steps. However there is no `setOrbitType`

method in `NumericalPropagatorBuilder`

as in `NumericalPropagator`

, so I can’t use it as in topic2. I found a solution by setting the initial orbit as an equinoctial one. Bellow an example:

```
orbit = EquinoctialOrbit(initial_spacecraft_state.getOrbit())
propagator_builder = NumericalPropagatorBuilder(orbit, integrator_builder, PositionAngle.MEAN, 1.0, attitude_provider)
```

Is it the right way to solve this issue ?

Thanks a lot,

Kind regards,

Stéfan