Hi all, First of all, great job on OREKIT, it’s a really nice tool! I’m trying to compare its orbit determination and propagation (so far it seems very accurate) with other softwares like STK or GMV but I have some trouble writing an OEM file after an orbit propagation. I based my code on the tutorials « EphemerisMode » and « MasterMode » (found in Propagation) and modified it in order to obtain the « bounded propagator » containing the computed ephemeris data (that works well) : <definition of the different useful data, initial orbit, integrator, etc.> // Propagator NumericalPropagator propagator = new NumericalPropagator(integrator); propagator.setOrbitType(propagationType); // Set up initial state in the propagator propagator.setInitialState(initialState); // Set the propagator to ephemeris mode propagator.setEphemerisMode(); // Extrapolate from the initial to the final date SpacecraftState finalState = propagator.propagate(lastDate); // Getting the integrated ephemeris BoundedPropagator ephemeris = propagator.getGeneratedEphemeris(); Now what I would like to do is export that data in an OEM file. Therefor, I looked into the OEMWriterTest file in order to see how you did it for the tests but it seems that you always use an EphemerisFile/OEMFile created by parsing an existing OEM file ! final OEMFile oemFile = parser.parse(inEntry, "OEMExample.txt"); final EphemerisFile ephemerisFile = (EphemerisFile) oemFile; OEMWriter writer = new OEMWriter(interpolationMethod, originator, objectID, objectName); writer.write(tempOEMFilePath, ephemerisFile); Is there a way to create such OEMFile or EphemerisFile based on a BoundedPropagator ephemeris ? Or is it possible to write directly from the BoundedPropagator ? I couldn’t find any constructor using such parameter… Other quick question : is it possible to write the OEM file with the covariance matrix ? Is this covariance matrix even available after a propagation ? Thanks in advance for your help Nicolas |