EOP 20 C04 series for 1962-2023

Available downloads

Content

Combined Earth Rotation Parameter solution consistent with the International Terrestrial Reference Frame (ITRF) 2020

Features:

1) Contain daily values of 8 Earth Rotation parameters with their formal errors:

- Pole coordinates x, y (")
- UT1 - UTC (ms)
- Celestial pole offsets dX, dY or dPsi, dEps (")
- Pole coordinate rates xrt, yrt ("/day)
- Length of day offset LOD (ms)

2) Download from https://hpiers.obspm.fr/iers/eop/eopc04/

4 versions:

eopc04.1962-now : sampled values at 0hUT / dX, dY IAU 2000
eopc04.dPsi_dEps.1962-now : 0hUT / dPsi, dEps IAU 2000
eopc04.12h.1984-now : 12hUT / dX, dY IAU 2000
eopc04.dPsi_dEps.12h.1984-now : 12hUT / dPsi, dEps IAU 2000


3) From 1/1/1994 to 31/12/2020 the 12hUT values of the pole coordinates x,y and of their rates xrt and yrt
exactly coincide with the corresponding values obtained for the ITRF 2020 solution.


4) Vondrak combined smoothing:
from 1/1/1984 for UT1 and LOD
from 1/1/2021 for x,y and ther rates

5) From 1/1/962 to 31/12/1984, ERP values of those of the C0414 solution

6) Calibration of the formal uncertainties of the input individual ERP series according to the dispersion with other kindred series

7) Removal of systematic bias / annual terms with respect to ITRF 2020 solution (x, y) and IVS (UT1, dX, dY)

8) Centers contributing to

x, y : ITRF 2020 (1994-2021), IGS F (1998-1994, 2021- ), ILRS (2021-), IDS (2021-), IVSR (2021-)
UT1 : IVSF (1984-2020), IVSR (from 2021), IAA Intensive, USNO Intensive, BKG Intensive
dX, dY : IVSF (1984-2020), IVSR (from 2021)
xrt, yrt : ITRF 2020 (1994-2021), IGS F (1998-1994, 2021- )
LOD : IGS F (1998- ), IGS-R (current year), CODE (current year)

Format

ASCII
Format Description

4(i4),f10.2,2(f12.6),f12.7,2(f12.6),2(f12.6),f12.7,2(f12.6),f12.7,2(f12.6),2(f12.6),f12.7
Documentation

General information: ftp://hpiers.obspm.fr/iers/eop/eopc04/C04.guide.pdf
Information on updates: http://hpiers.obspm.fr/iers/eop/eopc04/updateC04.txt
Publications:
Title

EOP 20 C04 series for 1962-2023
Data

Date [yyyy mm dd], MJD, x["], y["], UT1-UTC[s], dX["], dY["], xrt["], yrt["], LOD[s], x Er, y Er, UT1-UTC Er, dX Er, dY Er, xrt Er, yrt Er, LOD Er
Data Points

22513
Time Start

1962-01-01
Time End

2023-08-21
Time Interval

1 day
Accuracy 
-                       Min          Max      Average      Average (last 365 days)
sigma_X ["]         0.000047     0.030000     0.006461     0.000064
sigma_Y ["]         0.000039     0.030000     0.006436     0.000056
sigma_UT1-UTC [s]  0.0000028    0.0040747    0.0005861    0.0000165
sigma_LOD [s]      0.0000142    0.0014310    0.0003382    0.0000258
sigma_dX ["]        0.000027     0.010457     0.001150     0.000120
sigma_dY ["]        0.000024     0.006861     0.000832     0.000069
Keywords

EOP, Long term series, 20 C04, IAU 2006/2000A
Frequency

daily
Source

ftp://hpiers.obspm.fr/iers/eop/eopc04/
Created by

IERS Earth Orientation Centre
Published by

IERS Earth Orientation Centre
Date

2023-09-20
Contact

services.iers@obspm.fr
Distribution

onLine