Ricerc@Sapienza

In the last few years, Android smartphones became the leading products within the GNSS mass-market world after the release of the Android Raw GNSS Measurements API, developed from Google, and the technological developments led by handset manufacturers. The latters result in multi-band and multi-GNSS chipset now embedded in common smartphones - e.g. Xiaomi Mi 8. The Google API, allowing the reconstruction of traditional GNSS observations, paved the way to the development of new and more precise GNSS-based applications for Android smartphones.
The aim of this research project is to assess the possibility of using GNSS observations from Android devices in the reconstruction of geophysical phenomena interesting the Earth surface and/or the ionospheric layer levereging on two variometric algorithms developed in the Geodesy and Geomatics Division: VADASE and VARION. In particular, VADASE (Variometric Approach for Displacement Analysis Stand-alone Engine) will be used to retrieve 3D velocity of a stand-alone receiver - Android smartphone in this case - in real-time, and VARION (Variometric Approach for Real-Time Ionosphere Observations) will allow the real-time estimation of sTEC (Total Electron Content) variations reletad to TIDs (Travelling Ionospheric Disturbances). The quality of GNSS measurements from Android smartphones, dependent on the extremely low-cost GNSS antenna used, requires the definition of data quality handling algorithms to avoid and exclude faulty measurements and/or cycle slip affecting the variometric phase observations used inside VADASE and VARION.
The research project results will be a reference study on whether or not Android GNSS data may be used in GEO Big Data analysis to densify the actual knowledge available in the case of geophysical events reconstruction.