[1] YUAN Y B, OU J K.An Ionospheric Delay Correction Model Fitted to GPS Observations.In:Annual meeting of China Geophysics。 Hangzhou 。1998

[2] YUAN Y B, OU J K.Using GPS to investigate the variation law of ionospheric dalay and T EC.GPS World of China, 2000, 26(1):19～21

[3] YUAN Y B, OU J K.The First Study of Establishing China Grid Ionospheric Model.In:The proceeding of ION -GPS 2001, Utah:Salt Lake Cit y, 2001.2516 ～ 2524

[4] YUAN Y B, OU J K.Differential Areas for Differential Stations(DADS)———A New Method of Establishing Grid Ionospheric Model.Chi-nese Science Bulletin, 2002.47(8):636 ～ 639 (In Chinese)

[5] YUAN Y B, OU J K。The Effectsof Instrumental Bias in GPS Observations on Determining Ionospheric Delays and the Methods of Its Cal-ibration.Act a G eodaetica et Cart ographica Sinica, 1999, 28(2):110 ～ 114 (It is also selected as one of Papers for English Edit ion, Act aG eodaeti ca et Cartographi ca Si nica, Publi shed by Publishing House of S urveying and M apping Chinese Society of G eodesy, Phot ogrammet ry and Cart ography, 1999 。57 ～ 63)

[6] YUAN Y B, OU J K.Further Research on Ionospheric Delay Correction Method for Single -Frequency GPS User in WAAS.Acta Geo-daet ca et C artographica Sinica, 2000, (S up):96 ～ 102

[7] YUAN Y B, OU J K.An Improvement on Ionospheric Delay Correction for Single Frequency GPS User———the APR-IScheme.Journal of Geodesy, 2001, 75(5/6):331 ～ 336

[8] YUAN Y B, OU J K.Auto-Covariance Estimation of Variable Samples(ACEVS)and its Application forMonitoring Random Ionosphere Us-ing G PS.Journal of G eodesy, 2001, 75(7/8):438 ～ 447

[9] YUAN Y B, OU J K.A New Idea of Using GPS to Determine Ionospheric Delay ———Ionospheric Eclipse Factor Method(IEFM)。200。(to be submitted)