Product: Bulletin A
IERS Bulletin A Volume XXXIX Number 016 - Version metadata

IERS Bulletin A contains Earth orientation parameters x/y pole, UT1-UTC and their errors at daily intervals and predictions for 1 year into the future.

The contents of IERS Bulletin A are divided into four sections:

1. General information including key definitions and the most recently adopted values of DUT1 and TAI-UTC.
2. Quick-look daily estimates of the EOPs determined by smoothing the observed data. This involves the application of systematic corrections and statistical weighting. The results are published with a delay of about one to three days between the date of publication and the last available date with estimated EOP.
3. Predictions of x, y, and UT1-UTC, up to 365 days following the last day of data. The predictions use similar algorithms based on seasonal filtering and autoregressive processing for x, y, and UT1.
4. The combination series for the celestial pole offsets. Bulletin A contains celestial pole offsets with respect to the IAU1980 Nutation theroy (dpsi and deps) and the IAU 2000 Resolutions (dX and dY), beginning on 1 January 2003.

ASCII

See contents of the file or
http://hpiers.obspm.fr/eoppc/bul/bulb/explanatory.html [.rtf]

Explanatory supplement to IERS Bulletins A and B:
http://hpiers.obspm.fr/eoppc/bul/bulb/explanatory.html [.rtf]

Description of contents:
https://maia.usno.navy.mil/ser7/readme.bulla

Homepage of the IERS Rapid Service and Prediction Centre
https://maia.usno.navy.mil/

IERS Bulletin A Volume XXXIX Number 016

section 1: DUT1 [sec], TAI-UTC [sec]
section 2: x [''], y [''], UT1-UTC [sec] and their errors
section 3: Predictions for x [''], y [''], UT1-UTC [sec]
section 4: dpsi, deps, dX, dY ([msec of arc]) and their errors

section 1: 2
section 2: 7
section 3: 365
section 4: 2x18

section 2: 2026-04-10
section 3: 2026-04-17
section 4: 2026-03-25

section 2: 2026-04-16
section 3: 2027-04-16
section 4: 2026-04-02

1 day

Section 2:
                    Min       Max   Average
      x ["]:    0.00009   0.00009   0.00009
      y ["]:    0.00009   0.00009   0.00009
UT1-UTC [s]:   0.000005  0.000018  0.000013

Section 3: Estimated accuracies are:
    Predictions     10 d   20 d   30 d   40 d
        x,y ["]    0.004  0.007  0.010  0.013
    UT1-UTC [s]    0.0014 0.0024 0.0032 0.0040

Section 4: [msec. of arc]
                    Min       Max   Average
         dX:      0.384     0.624     0.496
         dY:      0.022     0.106     0.067

						

EOP, Rapid, Bulletin A, Earth orientation parameter, Volume XXXIX, Number 016

weekly

https://maia.usno.navy.mil/ser7/ [ser7.dat]

IERS Rapid Service Prediction Centre

IERS Rapid Service Prediction Centre

2026-04-16

usn.ncr.navobsydc.mbx.eopcp@mail.mil

onLine

https://maia.usno.navy.mil OR https://www.iers.org/subscription.html

XXXIX

016