How can I import the existing data?

Orekit usage
1

Hello everyone,

During the use of Orekit, I encountered an issue. I want to perform orbit improvement and need to import the data I already have. Could you please suggest which library or data interface would be best for this purpose?
James

2

Hello @lebronjames,

Could you explain your need in further details :

  • What do you mean by orbit improvement ? I guess it is orbit determination ?
  • Do you mean adding new measurements ? It seems like you need to use a Kalman filter ?

Cheers,
Vincent

4

Hi，Vincent
First of all, thank you for your response.I want to detemine the orbit。 Given the initial orbit, import existing measurement data, including the satellite’s time, the distance from the satellite to the ground station, azimuth, and elevation angles for a certain period. Using least squares to further refine the initial orbit and perform orbit determination. However, I do not know how to import the existing observation data into the BatchLSEstimatorfor further orbit determination.My observation data file format supports CSV or TXT. If you have any ideas or suggestions on how to proceed, I would be very grateful.
cheers！
james

5

You’re welcome, it wasn’t much :sweat_smile:.

I think your best bet is to create some custom converter to convert your csv/txt measurements files into existing Orekit measurements classes :

  • AngularAzel measurements for azimuth/elevation angles
  • Range measurements to use the distance

Check out this link to see the available measurements’ javadoc and this link for the list of measurements handled by Orekit for the latest version.

In addition, you will be able to write CCSDS TDM files once your measurements are converted into Orekit measurements.

I suggest you to use the Orekit python wrapper to perform these convertions but this is only my opinion.

Hope this helps !

Cheers,
Vincent

6

Heya,

There are some useful examples at laser-orbit-determination/02-orbit-determination-example.ipynb at master · GorgiAstro/laser-orbit-determination · GitHub , you will generally have to write the importer yourself built upon a similar method. If you’re comfortable in Python the Pandas library has tools to read csvs and process which can then be iterated through to create orekit measurements.

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