1. A computer implemented method of providing improved real time kinematics determination, comprising: determining, via a computing device, a first position estimate; performing an ambiguity resolution function having an output that provides an ambiguity resolution of the first position estimate by decorrelating first and second measurements, wherein the first and second measurements are inputs to the ambiguity resolution function; selecting a model of distance dependent and distance independent errors in the first and second measurements; and deriving a second position estimate as an output from a filter by inputting into the filter the output of the ambiguity resolution function and the distance dependent and distance independent errors.