****************************************************************************** dorismail 15-Jan-2007 13:19:18 Message No 0479 ****************************************************************************** Author: "H. Fagard" Subject: Antenna change at Marion Island (South Africa) Dear Colleagues, The antenna at Marion Island (Indian Ocean, South Africa), was found broken and significantly tilted on April 14, 2006, and repaired on April 29 (see DORISmail No 0453). It was replaced on November 9, 2006 with a brand new one, same model (Starec), on the same support. The acronym (MATB) and the DOMES number (30302S008) for the reference point are unchanged, since it is very close (within 2 mm) to the position before the antenna damage. On June 8, 2006, I wrote in DORISmail No 0456: >The antenna was repaired using epoxy and fibreglass, and put back to >its original position on April 29. The centring of the antenna was checked before removal. In fact it was slightly tilted towards NW: the 2 GHz phase centre offset with respect to its theoretical position (i.e. exactly above the antenna base) was found equal to: dE = -0.008 m dN = -0.009 m which is equivalent to: dX = 0.000 m dY = -0.010 m dZ = -0.006 m The story of the different positions of the MATB antenna is summarized in the following table, where the horizontal offsets are those of the 2 GHz phase centre: Start End 21-08-2004 12-04-2006* OK and centred 13-04-2006* 28-04-2006 Broken, skew (8 cm towards ESE) 29-04-2006 07-11-2006 Repaired, slightly skew (1 cm towards NW) 09-11-2006 current New antenna, centred *as mentionned in DORISmail No 0453, the exact date of the antenna break is not known. It happened between mid-January and April 14, but there is a presumption (from the DORIS data analyses) that it happened on April 13. Best regards, Herve Fagard -- ====================================================================== Herve FAGARD e-mail : herve.fagard@ign.fr Institut Geographique National 94165 SAINT-MANDE CEDEX PHONE : + 33 1 43 98 81 48 FRANCE FAX : + 33 1 43 98 84 50 ====================================================================== Cliquez sur l'url suivante https://www.mailcontrol.com/sr/ohJ3i!ZNcYcP8P8MK0zImqcCVVekCOrCFAQJu5wr!csVtOts64HSAuJov3KUh+SEKr8iaUaEPwWsSdxiCH!kCsH9GGYA!bpBeounqdOext7Ka5w4EtffVa6DKOEUHsFeRwJUoZychCF!9WRQsWhM71jTdpo+LTXRlz63Uk5fl8437VI2QguAYn!YNRN76MfPoOfiL+FV+7M2vgQ94XNkExyWjPys3BJN si ce message est indésirable (pourriel). Please do not reply directly to this message, but send comments and suggestions to IDS.central.bureau@cls.fr