method can either be given as 0 or 1. A value of 0 means that the OBT-MET fit uses ready-made time correlation data that have been corrected for signal propagation delays using predicted orbit data. time. A value of 1 forces this calculation to be re-done with more accurate reconstructed orbit data. This value is ingored if TCX data is used, since the Reconstructed Time Correlation data is already corrected.
The value assigned to deg chooses one of two possible options for the interpolating function:
igngshov can either be given as 0 or 1. A value of 1 means that all groundstation handovers in the time correlation data are ignored, i.e., all data from all stations are considered in the construction of the fit polynomial. igngshov=0 on the other hand will trigger that all time correlation data after a handover are not taken into account, i.e. the fit polynomial is constructed just on the basis of the data from the first ground station alone. In the past there have been cases where the ground times of different stations varied by an amount large enough to make the OBT-MET fit fail. If this happens the igngshov provides a way to work around the problem such that processing of the ODF in question can be performed. Please note that this can only be a temporary measure and that the anomaly should be brought to the attention of the SOC. The default value of igngshov is 1.
The actual values of method, deg, rms, frac, and igngshov shall be written to corresponding attributes TFIT_RPD, TFIT_DEG, TFIT_RMS, TFIT_PFR, TFIT_IGH in the event list being processed.
Caution: Please alter the above parameters via SAS_OBT_MET_FIT only when you exactly know what you are doing. Out-of-range conditions are caught but improper values can lead to inaccurate event arrival times.
XMM-Newton SOC/SSC -- 2004-11-22