Main results of 2002-2011-researches and development of GNSS observation processing methods and algorithms are presented, the components of being created software and algorithms complex of centralized post processing of kinamatic and static (single-and dual-frequency) code and carrier-phase user and permanent reference station observations are briefly described. The alternative strategy of carrier-phase and code GNSS observation network processing for high precision kinematic and static centimeter accuracy posotioning in conditions of sparse GNSS station networks is brifly described, A new approach allows to increase up to ~ 200 km the baselines in the networks of reference stations and to use widely a relatively low cost single frequency GNSS equipment retaining dual frequency positioning precision. The experimental results proving the obtaining of reliable carrier-phase ambiguity resolution and centimeter level dual- and single-frequency positioning at ~100 km removal from the nearest reference station of network are presented.