jgg     2012 32 (4):  144-147    ISSN: 0412-1961  CN: 21-1139/TG RESEARCH ON DLL DISCRIMINATOR OF GPS SOFTWARE RECEIVER Sun Fuyu 1) ; Zhang Peng 1,2) ; Xu Yaming 1,2) ; and Shen Zhijuan 1) 1)School of Geodesy and Geomatics, Wuhan University. Wuhan 430079;2) The Key Laboratory of Precise Engineering and Industry Surveying, State Bureau of Surveying and Mapping, Wuhan 430079 Received: 1900-01-01  Revised: 1900-01-01  Online: null Supporting info null