[IGSMAIL-6266] updated IERS Conventions Chapters 6, 7, 9

[Gérard Petit]

Author: Gérard Petit (IERS Conventions Center)

Information on the updates to the IERS Conventions

The IERS Conventions Center informs of the following updates.

Three chapters of the IERS Conventions have been updated:

* Chapter 6 "Geopotential" has been updated on 19 September 2010, 
see http://tai.bipm.org/iers/convupdt/convupdt_c6.html.

The section 6.3 "Effect of the ocean tides" has been rewritten, and the tide
model FES2004 
is described (main contributors are S. Bettadpur, R. Biancale and J. Ries). 
The introduction has been expanded to present general notions.


* Chapter 7 "Displacement of reference points" has been updated on 21
September 2010,
see http://tai.bipm.org/iers/convupdt/convupdt_c7.html.

The chapter has been reorganized to consider three kinds of displacements,
see the chapter's introduction for details.
A new section treats "S1-S2 atmospheric pressure loading" based on the work
of T. van Dam and R. Ray; the model is implemented at
http://geophy.uni.lu/ggfc-about/tide-loading-calculator.html, see the text
for details.


* Chapter 9 "Models for propagation delays" has been updated on 21 September
2010: 
see http://tai.bipm.org/iers/convupdt/convupdt_c9.html.

A mean a priori model for gradients is given along with information on its
use
for radio techniques (provided by J. Boehm).


Gérard Petit and Brian Luzum
IERS Conventions Center