Orbit determination- BatckLSEstimattion : unable to compute hyperbolic eccentric anomaly from the mean anomaly after 50 iterations

Hi all,

I am new to Orekit and tring out how to use BatchLSEstimator for orbit estimation. I am using python Wrapper and using simulated range data for Orbit determination. I tried the example by Clément Jonglez in the tutorial with my simulated data.
I am getting the error ‘unable to compute hyperbolic eccentric anomaly from the mean anomaly after 50 iterations’
The data is from two stations and collection period is from 2 days.
Unlike the example the two stations are relatively close (approximately 1,158.8 km apart)

Does anyone has any idea why the error is comming?
Also does the parameters and method in the example only work with laser ranging data ?
What sort of changes are required to determine orbit from data that is not geographically spaced ?

Thank you in advance.

Hi @niluj,

Welcome to the Orekit community !

Difficult to say without a working test case. The error means your orbit is getting hyperbolic so there must be something wrong with your measurements (check the units of measurements, the fact that they are one-way or two-way, or the station (lat, long, alt) maybe ?)

Batch least-square OD in Orekit can work with any of the measurements already available within the library: range, angular az/el or ra/dec, Doppler etc.
Here is list (see Orbit Determination section), and here is the Java package containing the measurements’ definition in the source code.

Now, as for @yzokras example, I cannot say if it only works with laser ranging data. I guess you can use any type of measurements but you will have to produce or parse the data and adapt the outputs accordingly.

Could you elaborate on this question please ? I’m not sure to understand what you mean.
Orekit OD doesn’t need the measurements to be “geographically spaced”.

Hope this helps,

Hi @niluj and @MaximeJ

For the mean to hyperbolic conversion, an issue has been recently opened (with a related merge request):

It could be related to your problem. Maybe it could solve it. However, as Maxime said, it would be very useful to have a working test case to reproduce your issue.

Best regards,

Thank you @bcazabonne, I wasn’t aware of that issue.

Thank you @bcazabonne . Actually there was an error with the measurement times. After correcting it the error disappeared.