Assessment of a Dual-frequency Carrier Phase Multi-Constellation Enabled Smartphone

Abstract

With the advancement of the Global Navigation Satellite System (GNSS) in the private sector, many new capabilities have been created to provide accurate location information. Due to the introduction of dual-frequency carrier phase multi-constellation GNSS smartphones significant performance improvements in terms of positioning accuracy and precision are achieved compared to previous phone generations. Advantages are also that time-to-first-fix is much faster and multipath can be suppressed considerably. Especially in densely populated environments, a multi-frequency receiver has the advantage of better controlling shadowing caused by buildings. The study addresses the research question of how a dual-frequency smartphone performs in contrast to an expensive geodetic receiver. To answer the following question two measurement scenarios were carried out. The first experiment was performed in an open sky environment on benchmarks which coordinates are precisely known on a roof top. Positioning methods such as Single Point Positioning (SPP), Precise Point Positioning (PPP) and static measurement methods were applied and compared with the results of a geodetic receiver. In the second scenario measurements were carried out in a more challenging environment under tree canopy. In addition a second station was located close to the one under the trees with free satellite visibility. The smartphone and geodetic receiver exchanged location and measured on both established points. The assessment showed that the smartphone does not always provide stable and good results. For static positioning the most reliable results were achieved. SPP performed as expect with deviations on the several meter level. PPP solutions depend very much on the observation duration and it was seen that the convergence time for resolving the carrier phase ambiguities might be very long.