Triple-frequency GNSS has been intensively studying in the past decades, especially with the open service of China’s BeiDou system. In this review, we will address the ambiguity resolution, benefits gained from additional frequency signals compared to the dual-frequency GNSS signals, as well as analyse the challenges of triple-frequency GNSS for future development. We first review and compare t...

There are some fundamental limitations on positioning accuracy using satellite navigation technique. Several sources of errors limit the accuracy of GNSS (Global Navigation Satellite System) positioning. The errors due to the earth’s atmosphere have the largest value and must be significantly reduced in order to achieve more precise positioning results. The GNSS-based determination of the posit...

In this study we report on the sintering behavior, microstructure and electrical properties of Al-doped ZnO ceramics containing 0-0.2 wt. % graphene sheets (AZO-GNSs) and processed using spark plasma sintering (SPS). Our results show that the addition of <0.25 wt. % GNSs enhances both the relative density and the electrical resistivity of AZO ceramics. In terms of the microstructure, the GNSs a...

Global Navigation Satellite Systems (GNSS)-based attitude determination is a viable alternative for traditional methods such as gyroscopes. Precise attitude determination using multiple GNSS antennas mounted on a remote sensing platform relies on successful resolution of the integer carrier phase ambiguities. The Multivariate Constrained (MC-) LAMBDA method has been developed for the multivaria...

This work addresses the accuracy of the Global Navigation Satellite Systems (GNSS)-Reflectometry (GNSS-R) scatterometric measurements considering the presence of both coherent and incoherent scattered components, for both conventional GNSS-R (cGNSS-R) and interferometric GNSS-R (iGNSS-R) techniques. The coherent component is present for some type of surfaces, and it has been neglected until now...

Sea level is traditionally observed with tide gauges (TG). These measurements are relative to the Earth’s crust. To improve the understanding of sea level changes it is necessary to perform measurements with respect to the Earth’s center of mass. This can be done with satellite techniques. Global Navigation Satellite System (GNSS) is a tool that can solves several hundred kilometers vectors wit...

Dual-frequency Global Positioning System (GPS) Real-time Kinematics (RTK) has been proven in the past few years to be a reliable and efficient technique to obtain high accuracy positioning. However, there are still challenges for GPS single-frequency RTK, such as low reliability and ambiguity resolution (AR) success rate, especially in kinematic environments. Recently, multi-Global Navigation S...

We installed two global navigation satellite system (GNSS) antennas on a research vessel, the RYOFU MARU of the Japan Meteorological Agency, and conducted experimental observations to assess the GNSS-derived precipitable water vapor (PWV) from October 19, 2016, to August 6, 2017. One antenna was set on the mast (MAST), while another antenna was set on the upper deck (DECK). The GNSS analysis wa...

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the signals can become a valuable data source, from which geophysical properties can be deduced. This approach, called GNSS-Reflectometry (GNSS-R), can be used to develop i...