GNSS positioning system and method using multiple processing threads

A plurality of GNSS satellite signals feeds multiple signal processing engines, each operating in certain processing mode including carrier smoothed pseudorange positioning, precise point positioning (PPP), pseudorange differential (DGNSS), carrier phase differential (RTK). Each processing engine (or processing thread of the same engine) runs the same unified numerical algorithm and uses the same or different sets of parameters. All engines can use the same set of signals, or the set of signals can be split into non-intersecting subsets, or the set of signals can be split into the overlapping subsets. Each engine produces estimates of certain parameters, namely carrier phase ambiguities and ionospheric delays for each satellite. These estimates are then combined into a resulting estimate which in turn is used for calculation of the final position reported by the receiver.