IGS Analysis Center Workshop - IGS - NASA

and NGS. Note that the day to day variations are not significant y larger than the variations of theother two components.2.3 Results from the January orbit tests.The main purpose of reprocessing the last two weeks of January 1993 was to study the differencesbetween solutions from the different Processing Centers under controlled conditions such as usingthe same fixed station coordinates. Tables 2.2a and 2.2b summarize the mean and sigma values forthe estimated Helmert parameters derived from the January orbit tests data (GPS weeks 680,681or Jan. 17-30). The results are given for both the original (Table 2.2b) and the reprocessed orbits(Table 2.2a). Note that the first day of the first week has been left out due to problems with PRN11 (a lack of data). Including this day would change the RMS considerably, making it unrealistic.Unfortunately not all the IGS reprocessed the data set or reprocessed the second week only. Thisis also reflected in the two tables below..Table 2.2a Mean and RMS of the Helmert Transf ormat ion Parameters for 1993January Orbit test.#Orb.RMSDX(m)DY(m)DZ(m)Rx(mas)RY(mas)RZ(mas)Scale(ppb)RMSCenter13.0-.005.002-.013.003.003.004.09.03-.06.03-.54.05.0.0.17 COD.0113.0 -.011.003-.003.003.011.003.20.03.03.03.00.06.5 .15 EMR.1 .018.0 -.035.006-.010.006.003.017.20.05.15.04.59.17.1.1.36 ESA.0113.0 .010.003.002.002-.016.002.00.04.22.03.63.11-.7.1.15 GFZ.017.0 .001.010-.017.005.097.007-1.93.17-1.00.09.08.13.1.3.34 SIO.0113.0.007.005.019.004-.008.004.13.13-.04.05-.32.11.4.1.23 UTX.0230