Thanks for your answers. Writing the OEM file works well indeed ! However I would have modified the format of the exported data in OEMWriter.writeEphemeris() in order to respect the CCSDS recommended standard for OEM files. Today, the format is set to « %16.16e » which means 16 digits after the decimal point (for example : -2.9007962960875825e+03) while the CCSDS recommends a mantissa of 16 digits (https://public.ccsds.org/Pubs/502x0b2c1.pdf, §6.5.5). A better format may then be « %21.14e ». 14 will allow to have a mantissa of 16 digits (1 before the point, the point and 14 after the point) while 21 allows to have a place for the sign (« - » or a blank space), the 16-digit mantissa and the 4 digit exponent (a character, the sign and a 2-digits integer). With this format, the previous example would look that way : -2.90079629608758e+03 What do you think about it ? Regarding the covariance : thanks, I’ll take a look at those pages ! Best Regards, Nicolas |