Implementation of real-time RTK/DGNSS on smartphones and positioning improvement for millions of users in Southeast Asia

Grab is Southeast Asia's leading superapp that provides everyday services like Deliveries, Mobility, Financial Services, and more. Location information is the backbone of our services, hence poor GNSS quality hurts our users' experience, especially our driver partners. The objective of this work is to explore the possibility of achieving precise positioning by implementing RTK/DGNSS on Android smartphones. In this contribution, we proposed a new service structure and pipeline to upload the GNSS raw measurements from the phone to the back end, the algorithm can support multiple users to conduct the RTK/DGNSS calculation concurrently. Road tests in different environments were conducted to evaluate the performance of our proposed methodology, and a study on the comparison between native mobile phone location output and our positioning service was done. The results show that in open sky scenarios, our algorithm performs much better than the native Android location, which confirms the interest of using the RTK/DGNSS to improve the positioning accuracy on Android devices for real business usage.