version 2
Source: Xpole,Ypole,Xrt,Yrt,LOD: weighted average of centres;
        UT1-UTC: integrated from the 5th day prior to Bull. A
                 last non-predicted value.

Orbits: to be used with the IGS Ultra Rapid Orbits (IGR)

  MJD      Xpole   Ypole  UT1-UTC    LOD  Xsig  Ysig   UTsig  LODsig  Nr Nf Nt    Xrt    Yrt  Xrtsig  Yrtsig
             (10**-6")       (0.1 usec)    (10**-6")     (0.1 usec)              (10**-6"/d)    (10**-6"/d)
53171.50  -56550  489432 -4725899  -1973    52    40     178     120   0  0  0   2899   1266     69     44
53172.50  -53966  490759 -4723360  -3010    49    42     199     132   0  0  0   2583   1355     29     27