[IGSMAIL-6272] Tranformation parametres between IGS reference frames realizations

[Stefano Ferri]

Dear list,

I've just subscribed to IGSmail in the hope to solve a problem.

I'm analyzing the time series of some IGS stations. Since the time interval spans from 1999 to 2009, I have 3 reference frame to dial with: IGS97, IGS00 and IGS05. I need to remove the jumps due to those reference frame changes, and I would like to transform all in the IGS05.
Therefore, looking on the ITRF website, I've found some documentation here:

http://itrf.ensg.ign.fr/trans_para.php

where  transformation parameters between all the ITRF reference frames are reported. These are not parametes between IGS reference frames, but since I've not found them, I've tryed anyway. After the Helmert transformation, I've converted cartesian coordinates into North, East and Up components. While North and East were succesfully corrected, the Up component shows a jump 2006, and a smaller one in 2001,  when there were the switches from IGS97 to IGS00 and from IGS00 to IGS05.

Since I've not found transformations parameters between IGS realization, but only between ITRFs, I would like to know if there is a webpage or some documents repporting the official parameters. IGS' are aligned to ITRFs, but is it correct to use the parameters reported in the ITRF website for transformations between IGS realizations of the ITRF? Is there something like IERS' technical notes containing IGS-related informations?
Could it be possible that the switch from relative to absolute antenna calibrations causes the jump in the Up component? If so, how to estimate it?


Thank you in advance for any reply.

Best regards,
Stefano Ferri


-- 
Stefano Ferri
Department of Physics - Sector of Geophysics
University of Bologna
Viale Berti Pichat 8, 40127 Bologna - Italy
Tel. +39 051 2095066
Fax  +39 051 2095058