Ricerc@Sapienza

The main objective of this work is to investigate on precise positioning with a GPS and Galileo enabled chipset embedded in a smartphone. Sapienza research team, as member of the GSA GNSS Raw Measurements Task Force, with contribution by Politecnico di Milano, is investigating the area of real time precise positioning with single frequency, focusing on the benefits of multi-constellation GNSS and raw data quality provided by a smartphone. The analysis is carried out with code- and carrier-based algorithms in different scenarios.

In the past, the possibility to access to dual frequency GNSS was achievable only with expensive and high quality receivers, in environment and conditions that are different from the everyday lifestyle. The use of dual-frequency is relevant because it allows increasing the accuracy and the reliability on the user’s position estimation. The technological evolution has brought today the possibility to extend the advantages of the high accuracy positioning to a larger number of users and applications.

A new low-cost L1/L2c receiver board is presented in this short letter, along with its first tests. The main strength of the board is its low price tag (around 200 EUR, in quantities of hundreds) as an effective dual-frequency receiver. The effectiveness of the receiver was at first proven by a pedestrian walk experiment on a closed loop, allowing the evaluation of closure errors. Raw measurements were collected and processed in a real-time scenario through a variometric approach implemented in VADASE software.