Single-Baseline RTK Positioning Using Dual-Frequency GNSS Receivers Inside Smartphones

Abstract

Global Navigation Satellite System (GNSS) positioning is currently a common practice thanks to the development of mobile devices such as smartphones and tablets. The possibility to obtain raw GNSS measurements, such as pseudoranges and carrier-phase, from these instruments has opened new windows towards precise positioning using smart devices. This work aims to demonstrate the positioning performances in the case of a typical single-base Real-Time Kinematic (RTK) positioning while considering two different kinds of multi-frequency and multi-constellation master stations: a typical geodetic receiver and a smartphone device. The results have shown impressive performances in terms of precision in both cases: with a geodetic receiver as the master station, the reachable precisions are several mm for all 3D components while if a smartphone is used as the master station, the best results can be obtained considering the GPS+Galileo constellations, with a precision of about 2 cm both for 2D and Up components in the case of L1+L5 frequencies, or 3 cm for 2D components and 2 cm for the Up, in the case of an L1 frequency. Moreover, it has been demonstrated that it is not feasible to reach the phase ambiguities fixing: despite this, the precisions are still good and also the obtained 3D accuracies of positioning solutions are less than 1 m. So, it is possible to affirm that these results are very promising in the direction of cooperative positioning using smartphone devices.

Role of HD Maps in Unmanned Vehicles

“…Однако, получаемая точность недостаточна для движения автономных автомобилей в городе, поскольку в лучшем случае GNSS достигает метровой точности, в то время как автономное вождение требует точности определения местоположения до 5-10 сантиметров. В таком случае используют технологию RTKпоправок [12], которые позволяют достичь требуемой точности. Однако, в чистом виде GNSS RTK плохо подходит для движения в городских условиях из-за большого количества зон, где сигнал не может быть принят, например, в тоннеле или при движении в условиях плотной застройки.…”

Distributed Error Correction of EKF Algorithm in Multi-Sensor Fusion Localization Model

“…Location Based Services (LBS) is a basic service that obtains the current location and provides information resources through various mobile location technologies [1]- [3]. At present, the most basic localization technology generally uses GPS sensors for real-time localization, but GPS signals are easily blocked, or interfered, thus high-precision localization cannot be realized [4]- [6]. Therefore, based on a single data source, many research institutions, universities, etc.…”

Assessment of Static Positioning Accuracy Using Low-Cost Smartphone GPS Devices for Geodetic Survey Points’ Determination and Monitoring

“…In later Android versions, it was possible to turn off the duty cycling mode, making the observables applicable for phase-based positioning methods. Based on this, first single-baseline RTK positioning experiments considering two different kinds of multi-frequency and multi-constellation master stations took place [16]. This research work demonstrated that it is not possible to fix phase ambiguities and therefore to reach cm-accuracy in real-time, mostly due to the low quality of GNSS raw measurements collected by a mobile phone.…”