Over the last few years, many smartphones have been equipped with Global Navigation Satellite System (GNSS) technology, allowing people to use their own devices for positioning and location services. After the release of the Android Nougat (version 7) operating system, raw GNSS measurements (i.e., pseudorange, carrier-phase, Doppler shift, and carrier-to-noise density ratio (C/N0) observations) from smartphones and tablets became accessible, which...