jgg     2009 29 (2):  135-139    ISSN: 0412-1961  CN: 21-1139/TG REALIZATION AND MAINTENANCE OF TERRESTRIAL REFERENCE FRAME Wei Na ;and Shi Chuang GNSS Research Center, Wuhan University, Wuhan 430079 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null