Report for 2012 from the Bordeaux IVS Analysis Center

Abstract ThisreportsummarizestheactivitiesoftheBordeauxIVSAnalysisCenterduringtheyear2012.The workfocused on (i) regular analysis of the IVS-R1 and IVS-R4 sessions with the GINS softwarepackage;(ii)systematicVLBIimagingoftheRDVsessionsandcalculationofthecorrespondingsourcestructureindexandcompactnessvalues; (iii)investigationofthecorrelationbetweenastrometricpo-sition instabilities and source structure variations; and (iv) continuation of our VLBI observationalprogram to identify optically-bright radio sources suitable for the link with the future Gaia frame.Alsoofimportanceisthe11thEuropeanVLBINetworkSymposium,whichweorganizedlastOctoberinBordeauxandwhichdrewmuchattentionfromtheEuropeanandInternationalVLBIcommunities. 1. General Information The “Laboratoire d’Astrophysique de Bordeaux” (LAB), formerly Bordeaux Observatory, islocated in Floirac, near Bordeaux, in the southwest of France. It is funded by the University of Bor-deaux and the CNRS (“Centre National de la Recherche Scientifique”). VLBI activities are primar-ily developed within the M2A team (“M´etrologie de l’espace, Astrodynamique, Astrophysique”).The contribution of the Bordeaux group to the IVS has been mostly concerned with the main-tenance, extension, and improvement of the International Celestial Reference Frame (ICRF). Thisincludes regular imaging of the ICRF sources and evaluation of their astrometric suitability, aswell as developing specific VLBI observing programs for enhancing the celestial reference frame.In addition, the group is in charge of the VLBI component in the multi-technique GINS softwarepackage [1] as part of a collaborative effort within the French “Groupe de Recherches de G´eod´esieSpatiale” (GRGS) to combine VLBI and space geodetic data (SLR, GPS, and DORIS) at theobservation level. This effort also involves space geodesy groups in Toulouse, Grasse, and Paris.