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Appendix A: Ephemeris file formats

1.1 File formats

Common ephemeris formats are CCSDS OEM, NASA ITC format, or ILRS CPF. They provide additional information such as the used frame (e.g., EME2000, TEME, ITRF), interpolation method and order, and manoeuvre epochs. ILRS CPF files are used within the satellite laser ranging community for station predictions. Operators of laser ranging stations often prefer the ITRF frame to simplify the computation (as there is no need for any frame conversions).

1.1.1. Example CCSDS OEM

File extracted from the standard.

CCSDS_OEM_VERS = 2.0
CREATION_DATE = 1996-11-04T17:22:31
ORIGINATOR = NASA/JPL
META_START OBJECT_NAME = MARS GLOBAL SURVEYOR
OBJECT_ID = 1996-062A
CENTER_NAME = MARS BARYCENTER
REF_FRAME = EME2000
TIME_SYSTEM = UTC
START_TIME = 1996-12-28T21:29:07.267
USEABLE_START_TIME = 1996-12-28T22:08:02.5
USEABLE_STOP_TIME = 1996-12-30T01:18:02.5
STOP_TIME = 1996-12-30T01:28:02.267
INTERPOLATION = HERMITE
INTERPOLATION_DEGREE = 7
META_STOP
1996-12-28T21:29:07.267 -2432.166 -063.042 1742.754 7.33702 -3.495867 -1.041945
1996-12-28T21:59:02.267 -2445.234 -878.141 1873.073 1.86043 -3.421256 -0.996366
1996-12-28T22:00:02.267 -2458.079 -683.858 2007.684 6.36786 -3.339563 -0.946654
...
1996-12-30T01:28:02.267 2164.375 1115.811 -688.131 -3.53328 -2.88452 0.88535
COVARIANCE_START
EPOCH = 1996-12-28T21:29:07.267
COV_REF_FRAME = EME2000
3.3313494e-04
4.6189273e-04 6.7824216e-04
-3.0700078e-04 -4.2212341e-04 3.2319319e-04
-3.3493650e-07 -4.6860842e-07 2.4849495e-07 4.2960228e-10
-2.2118325e-07 -2.8641868e-07 1.7980986e-07 2.6088992e-10 1.7675147e-10
-3.0413460e-07 -4.9894969e-07 3.5403109e-07 1.8692631e-10 1.0088625e-10 6.2244443e-10
EPOCH = 1996-12-29T21:00:00.000
COV_REF_FRAME = EME2000
3.4424505e-04
4.5078162e-04 6.8935327e-04
-3.0600067e-04 -4.1101230e-04 3.3420420e-04
-3.2382549e-07 -4.5750731e-07 2.3738384e-07 4.3071339e-10
-2.1007214e-07 -2.7530757e-07 1.6870875e-07 2.5077881e-10 1.8786258e-10
-3.0302350e-07 -4.8783858e-07 3.4302008e-07 1.7581520e-10 1.0077514e-10 6.2244443e-10
...
COVARIANCE_STOP
SATCON2 Algorithms Working Group Report
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