From jimr at ngs.noaa.gov Wed May 14 11:42:55 2003 From: jimr at ngs.noaa.gov (Jim Ray (NGS 301-713-2850 x112)) Date: Wed, 14 May 2003 14:42:55 -0400 (EDT) Subject: [IGSMAIL-4377]: possible shift at BRMU Message-ID: <200305141842.OAA19969@ngs.noaa.gov> ****************************************************************************** IGS Electronic Mail 14 May 11:43:30 PDT 2003 Message Number 4377 ****************************************************************************** Author: Jim Ray After equipment changes made at BRMU in March, it appears that there may be a small shift in the observed station coordinates. A Trimble 5700 receiver and TRM29659.00 antenna + UNAV radome replaced the previous ROGUE SNR-8000 receiver and AOAD/M_T antenna (no radome) on 12 March 2003; see IGS Mail #4297 and the site log. Based on data collected since that time, it appears that the observed station position may have shifted by about -4 mm in the North direction. Any possible change in the E or Up directions is probably not signficant. Users are cautioned to be aware of this possibility when using BRMU data for frame alignment where accuracies at the mm-level are sought. Note that BRMU is one of set of 54 stations used by the IGS to realize the IGS00 terrestrial reference frame.