GNSS Signalverabeitung for estimating MW biases

Method and apparatus are described for processing a set of GNSS signal data derived from code observations and carrier-phase observations at a plurality of receivers of GNSS signals from multiple satellites over multiple epochs, wherein the GNSS signals having at least two carrier frequencies, comprising an MW (Melbourne Wubbena) combination per receiver-satellite pair at each epoch to obtain a MW data set per epoch, and estimating the MW data set per epoch of a MW-bias per satellite, which vary from epoch to epoch can, and a set of WL (wide lane) ambiguities, each WL ambiguity corresponds to a receiver of a satellite connection and a satellite-receiver-satellite connection, wherein the MW-bias per satellite is formed as one of (i) a single parameter estimation and (ii) an estimated offset plus harmonic variations with estimated amplitudes.