Precise point positioning with ambiguity resolution using an external survey-grade antenna enhanced dual-frequency android GNSS data

摘要

A vast of applications that need low-cost and high-precision positions may arise with the advent of the world's first dual-frequency GNSS smartphone Xiaomi Mi 8. In this paper we succeeded in replacing the Mi 8's embedded GNSS antenna with an external survey-grade one and performing precise point positioning ambiguity resolution (PPP-AR) on this enhanced device. As for fixed static hourly solutions, all three components achieved centimeter-level accuracy, and the position errors were 1.6 cm, 1.0 cm and 2.4 cm in the east, north and up components. Compared with float solutions the improvements were up to 61%, 41% and 48% respectively. The kinematic solutions also showed remarkable improvements. In addition, we also studied ambiguity features and found that the ambiguity residuals were quite larger than those of survey-grade receivers due to frequent cycle slips and noisier raw measurements. Overall, we believe that it is possible to fix undifferenced ambiguities with Android dual-frequency GNSS data. (C) 2020 Elsevier Ltd. All rights reserved.