Product: Bulletin B
IERS Bulletin B Number 450 - Version metadata

Available downloads

Content

IERS Bulletin B provides current information on the Earth's orientation in the IERS Reference System. This includes Universal Time, coordinates of the terrestrial pole, and celestial pole offsets.
IERS Bulletin B consists of 5 sections:

Section 1:
Daily final values at 0:00 UT of x, y, UT1-UTC, dX, dY, and their uncertainties. Time span: one month with final values, one month with preliminary values.

Section 2:
Daily final values at 0:00 UT of celestial pole offsets dPsi and dEps in the IAU 1980 system and their uncertainties.

Section 3:
Earth angular velocity (daily estimates of LOD and OMEGA with their uncertainties).

Section 4:
Information on the time scales and announcement of occurring leap seconds.

Section 5:
Average formal precision of the individual and combined series contributing or not to the combination and their agreement with the combination.

Format

ASCII
Format Description

See contents of the data files or
ftp://hpiers.obspm.fr/iers/bul/bulb_new/bulletinb.pdf
Documentation

See contents of the data files and
ftp://hpiers.obspm.fr/iers/bul/bulb_new/bulletinb.pdf
Title

IERS Bulletin B Number 450
Data

Section 1: Year[yyyy],Month [mm], Day [dd], MJD, x [marcsec], y [marcsec], UT1-UTC [ms], dX [marcsec], dY [marcsec],x err[marcsec], y err[marcsec],UT1 err[marcsec], X err[marcsec], Y err[marcsec],

Section 2: Year[yyyy],Month [mm], Day [dd], MJD, dPsi1980[marcsec],dEps1980[marcsec],sig dPsi[marcsec],sig dEps[marcsec]

Section 3: Year[yyyy],Month [mm], Day [dd], MJD,LOD[ms],sigma[ms],OMEGA[mas/ms],sigma[mas/ms],

Section 4: TAI - UTC [s],

Section 5: RMS of x [marcsec], y [mas ], UT1 [ms], LOD[ms], dX [marcsec], dY [marcsec], Number of points
Data Points

Section 1: 61
Section 2: 30
Section 3: 30
Time Start

Section 1: 2025-06-02
Section 2: 2025-06-02
Section 3: 2025-06-02
Time End

Section 1: 2025-08-01
Section 2: 2025-07-01
Section 3: 2025-07-01
Time Interval

Section 1: 60
Section 2: 29
Section 3: 29
Accuracy 
-Section 1:                  min        max        avg
       sigma_X [mas]       0.031      0.033      0.032
       sigma_Y [mas]       0.027      0.030      0.028
  sigma_UT1-UTC [ms]       0.0182     0.0226     0.0201
      sigma_dX [mas]       0.011      0.019      0.014
      sigma_dY [mas]       0.007      0.009      0.008
Section 2:
    sigma_dPSI [mas]       0.028      0.048      0.034
    sigma_dEPS [mas]       0.007      0.009      0.008
Section 3:                  min                max                avg
      sigma_LOD [ms]       0.0112             0.0128             0.0119
sigma_OMEGA [mas/ms]       0.00000000195      0.00000000223      0.00000000207
Keywords

EOP, monthly, BULLETIN B, Earth orientation parameter, Number 450
Frequency

monthly
Source

http://hpiers.obspm.fr/iers/bul/bulb_new/bulletinb.450
Created by

IERS Earth Orientation Centre
Date

2025-08-01
Contact

services.iers@obspm.fr
Distribution

onLine
Email Subscription

http://hpiers.obspm.fr/eop-pc/products/bulletins/subscription.html OR http://www.iers.org/subscription.html
Number

450