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The advent of Global Navigation Satellite Systems (GNSS) initiated a revolution in Positioning, Navigation and Timing
(PNT) applications. Besides the enormous impact on geospatial data acquisition and reality capture, satellite navigation
has penetrated everyday life, a fact which is proved by the increasing degree of human reliance on GNSS-enabled smart
devices to perform casual activities. Nevertheless, GNSS does not perform well in all cases. Specifically, in GNSS-challenging
environments, such as urban canyons or forested areas, navigation performance may be significantly
degraded or even nullified. Consequently, positioning is achieved by combining GNSS with additional heterogeneous
information or sensors, such as inertial sensors. To date, most smartphones are equipped with at least accelerometers and
gyroscopes, besides GNSS chipsets. In the frame of this research, difficult localization scenarios were investigated to
assess the performance of these low-cost inertial sensors with respect to higher grade GNSS and IMU systems. Four
state-of-the-art smartphones were mounted on a specifically designed on-purpose build platform along with reference
equipment. The platform was installed on top of a vehicle, which was driven by a predefined trajectory that included
several GNSS-challenging parts. Consequently, positioning and inertial readings were acquired by smartphones and
compared to the information collected by the reference equipment. The results indicated that although the smartphone
GNSS receivers have increased sensitivity, they were unable to produce an acceptable solution for more than 30% of the
driven course. However, all smartphones managed to identify, up to a satisfactory degree, distinct driving features, such
as curves or bumps.
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