boundary="----_=_NextPart_001_01C99047.03BCEA37" ****************************************************************************** dorismail 16-Feb-2009 14:58:40 Message No 0583 ****************************************************************************** Author: "Lemoine, Frank G. (GSFC-698.0)" Subject: Information on the updates to the IERS Conventions This is a multi-part message in MIME format. ------_=_NextPart_001_01C99047.03BCEA37 Information on the updates to the IERS Conventions The IERS Conventions Center provides the following information on the updates to the IERS Conventions since IERS Message No. 139 (December 05, 2008). Chapter 7 "Displacement of reference points" has been updated on 10 February 2009, see http://tai.bipm.org/iers/convupdt/convupdt_c7.html: The section 7.2 "Models for the displacement of reference points of instruments" has been updated. It now contains models for a reference temperature (provided by J. Boehm), the thermal expansion of VLBI antennas (provided by A. Nothnagel) and GNSS antenna phase center offsets and variations (provided by R. Schmid). Each sub-section is intended to be a short presentation with links to other sites providing more complete information. The subroutine hardisp.f that computes the displacement due to ocean tidal loading has been updated by D. Agnew, following reports of a sign error in the long-period tides. The number of harmonics used and the internal precision have also been increased. Numerous typos have been corrected and other stylistic corrections introduced to the chapter, following remarks by R. Schmid. Chapter 9 "Models for propagation delays" has been updated on 12 February 2009, see http://tai.bipm.org/iers/convupdt/convupdt_c9.html . It now includes a new section "Ionospheric models for radio techniques", written by M. Hernandez Pajares with contributions by U. Hugentobler, F. Mercier and others. The title of the chapter has been changed accordingly (past title was "Tropospheric model"). Gerard Petit and Brian Luzum IERS Conventions Center ------_=_NextPart_001_01C99047.03BCEA37 Information on the updates to the IERS Conventions



Information on the updates to the IERS Conventions


The IERS Conventions Center provides the following information on the
updates to the IERS Conventions since IERS Message No. 139 (December 05,
2008).

Chapter 7 "Displacement of reference points" has been updated on = 10
February 2009, see http://tai.bipm.org/iers/convupdt/convupdt_c7.html:
The section 7.2 "Models for the displacement of reference points of
instruments" has been updated.
It now contains models for a reference temperature (provided by
J. Boehm), the thermal expansion of VLBI antennas (provided by
A. Nothnagel) and GNSS antenna phase center offsets and variations
(provided by R. Schmid). Each sub-section is intended to be a short
presentation with links to other sites providing more complete
information.
The subroutine hardisp.f that computes the displacement due to ocean
tidal loading has been updated by D. Agnew, following reports of a sign
error in the long-period tides.
The number of harmonics used and the internal precision have also been
increased.
Numerous typos have been corrected and other stylistic corrections
introduced to the chapter, following remarks by R. Schmid.

Chapter 9 "Models for propagation delays" has been updated on 12<= BR> February 2009, see http://tai.bipm.org/iers/convupdt/convupdt_c9.html .
It now includes a new section "Ionospheric models for radio techniques= ",
written by M. Hernandez Pajares with contributions by U. Hugentobler,
F. Mercier and others. The title of the chapter has been changed
accordingly (past title was "Tropospheric model").

Gerard Petit and Brian Luzum
IERS Conventions Center

= ------_=_NextPart_001_01C99047.03BCEA37-- Please do not reply directly to this message, but send comments and suggestions to IDS.central.bureau@cls.fr