The smartphone antenna’s poor multipath suppression and irregular gain pattern result in large time-correlated phase errors that significantly increase the time to integer ambiguity resolution as compared to even a low-quality stand-alone patch antenna. The time to integer resolution — and to a centimeter-accurate fix — is significantly reduced when more GNSS signals are tracked or when the smartphone experiences gentle wavelength-scale random motion.

Cite and download the article:
K.M. Pesyna, Jr., R.W. Heath, Jr., and T.E. Humphreys, "Accuracy in the palm of your hand," GPS World, February, 2015.