This paper starts with a brief review of scattering statistics theory for diffusely scattered radar signals. Following, global navigation satellite systems reflected (GNSS-R) signals are used to demonstrate the results of non-coherent signal averaging on the mean and standard deviation of the signal power fluctuations. The retrieved signal fading statistics of GNSS-R signals detected in low Ear...

Direct geo-referencing is an efficient methodology for the fast acquisition of 3D spatial data. It requires the fusion of spatial data acquisition sensors with navigation sensors, such as Global Navigation Satellite System (GNSS) receivers. In this contribution, we consider an integrated GNSS navigation system to provide estimates of the position and attitude (orientation) of a 3D laser scanner...

Ellipsodially referenced survey (ERS) is considered as one of the challenging issues in the hydrographic surveys due to the fact that the bathymetric data collected by this technique can be readily transformed either to the geodetic or the chart datum by application of some geoscientific models, such as geoid, hydrodynamic and sea surface topographic model. GNSS (Global Navigation Satellite Sys...

New positioning applications’ availability requirements demand receivers with higher sensitivities and ability to process multiple GNSS signals. Possible applications include acquiring one signal per GNSS constellation in the same frequency band and combining them for increased sensitivity or predicting acquisition of other signals. Frequency domain processing can be used for this purpose, sinc...

Civilian GNSS signal structures are publicly known and they are received with low power on the earth surface. These make GNSS signals susceptible to spoofing attacks. Hence, the requirement for proper mitigation techniques becomes a must in current and future GNSS receivers for robust, accurate and reliable positioning. This paper proposes a new antispoofing technique using an antenna array in ...

Shenzhen, the first special economic zone of China, has witnessed earth-shaking changes since the late 1980s. In the past 35 years, about 80 km2 of land has been reclaimed from the sea in Shenzhen. In order to investigate coastal vertical land motions associated with land reclamation, we proposed an elaborated Point Target (PT) based Small Baseline Subset InSAR (SBAS-InSAR) strategy to process ...

Current fast and reliable Internet services provide many advantages for worldwide GNSS users. Development of techniques using the Internet for streaming RTK/DGPS corrections allows mobile users to achieve high-accuracy positioning over both short and long baselines. Applications like GNSS Internet Radio are used for distributing raw GPS data and real-time corrections of GPS observations via RTC...

Grace Xingxin Gao, Ph.D., is a research associate in the GPS lab of Stanford University. She received the B.S. degree in mechanical engineering and the M.S. degree in electrical engineering, both at Tsinghua University, Beijing, China. She obtained the Ph.D. degree in electrical engineering at Stanford University. Her current research interests include GNSS signal and code structures, GNSS rece...

The city of Staufen im Breisgau in southwest Germany suffers from a localized land uplift, which has occurred in the past six years in relation to geothermal drilling activities in 2007. So far, severe damages at 269 buildings have been recorded. The chemical transformation of anhydrite and water to gypsum, resulting in a volume increase, has been attributed as the cause of the uplift. Previous...