Assessing Galileo Readiness in Android Devices Using Raw Measurements

Abstract

In the recent months, two GNSS milestones were crossed, introducing new capabilities and improving GNSS user experience. One of those milestones, reported by Google, was the availability of GNSS raw measurements, such as code or phase measurements, for Android 7. Prior to that, mass market applications users did not have the ability to improve GNSS positioning or take advantage of GNSS raw measurements. The second milestone was the launch of Galileo Initial Services in December 2016. For the first time, a European GNSS system became available to users, including Android 7 users, worldwide. Airbus is conducting a testing activity in support of GSA, putting the Galileo system in the newest Android 7 smartphones to trial under real world conditions. For testing, Airbus developed an app to access all available location information, such as navigation message, clock information, and GNSS measurements, for Android 7. This information is stored in the internal memory of the phone in the standard format (RINEX) and specific csv format in real time; thus, it does not need to be transmitted to the PC using Android Studio. Owing to the new Android 7 features and the developed app, we can characterize GNSS measurements (code and phase) in mass market devices. The second part of the testing activity involved assessing the quality of the measurements and comparing the different GNSS constellations with special emphasis on Galileo. The main objective was to prove the Galileo-ready statements of the manufacturers of Android devices. The last part of the testing activity involved deriving and comparing different PVT solutions based on raw measurements stored in the phone. The PVT solution can be computed based on only one constellation (such as Galileo, GPS. or GLONASS) or on different GNSS combinations. Performances of the Galileo system in the new smartphones were assessed. To ensure a completely controlled and dynamic development process, the PVT solutions are first computed outside the phone using dedicated Matlab scripts.