Reply-To: DORISMail Sender: DORISMail-owner@ensg.ign.fr Precedence: list ****************************************************************************** DORISMail 15-Feb-2001 15:28:56 Message No 0117 ****************************************************************************** Author: "H. Fagard" Subject: Antenna moving at Rio Grande Dear Colleagues, The DORIS Starec antenna at Rio Grande has been moved to a new support in order to improve its stability. Transmissions from the former antenna position (RIOB) stopped on Janary 8. When checking the current antenna (RIOB) we realised that one of the guy-wires was broken and the antenna out of vertical. Unfortunately it was not possible to measure this excentricity but I estimate it amounted to several centimeters, approximately towards the North. The station manager didn't know that the guy-wire had been broken, nor when this might have happened. He suspects that some contractor working on the site may have broken it and loosely fastened it to a metal beam lying about in the grass so that nobody would notice. This story confirms the need for the network renovation action, which was decided about one year ago and is now well under way, in order to improve the antenna support stability at many DORIS stations. The Santiago and Easter Island stations will be renovated at the end of this month, the Kerguelen and Amsterdam stations are next on the list with a planned visit in April, and other sites should be improved this year. Now the information about the new antenna location: It is now installed on a 60 cm diameter, 1.7 m high concrete pillar, built on a 2 m sided, 0.5 m deep concrete footing. The pillar and footing were constructed around a 17 cm diameter metal pipe, pile driven 7 m deep into the ground, and are reinforced with 2 cm diameter rods. Transmissions from the new antenna resumed on January 10. The acronym in the data files for the new antenna reference point is RIPB. The DOMES number for the antenna reference point is 41507S005. Its approximate coordinates (ITRF97, 1997.0) are: X = 1429899.135 m Y = -3495323.565 m Z = -5122723.577 m (sigma: 1 cm) 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 ======================================================================