Preprints
Filtering by Subject: Other Environmental Sciences
Using filtered and semi-continuous high rate GPS for monitoring deformations
Published: 2017-11-13
Subjects: Civil and Environmental Engineering, Civil Engineering, Construction Engineering and Management, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Geotechnical Engineering, Other Civil and Environmental Engineering, Other Earth Sciences, Other Environmental Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics, Structural Engineering
Multipath is a major sidereally-repeating error affecting precise GPS positioning and deformation monitoring. Because satellite-receiver geometry repeats almost exactly every sidereal day, filtering can reduce multipath in near-static situations. Here, we investigate how sidereal filtering can be used in a switched multi-antenna array system providing semi-continuous GPS data, which may be [...]
J2: an evaluation of new estimates from GPS, GRACE and load models compared to SLR
Published: 2017-11-13
Subjects: Earth Sciences, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Other Earth Sciences, Other Environmental Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
Changes in J2, resulting from past and present changes in Earth’s climate, are traditionally observed by Satellite Laser ranging (SLR). Assuming an elastic Earth, it is possible to infer changes in J2 from changes in Earth’s shape observed by GPS. We compare estimates of non-secular J2 changes from GPS, SLR, GRACE and a load model. The GPS and SLR annual signals agree but are different (16%) to [...]
An examination of network RTK GPS services in Great Britain
Published: 2017-11-13
Subjects: Civil and Environmental Engineering, Civil Engineering, Construction Engineering and Management, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Other Civil and Environmental Engineering, Other Earth Sciences, Other Environmental Sciences, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
As of March 2009, network real-time kinematic (RTK) GPS surveying is available in Great Britain with the aid of two commercial service providers, Leica’s “SmartNet” and Trimble’s “VRS Now”, both of which rely largely on the Ordnance Survey’s “OS Net” network of around 120 continuously operating reference stations. With the aim of testing the performance of Network RTK under both ideal and [...]
Ocean tide loading and relative GNSS in the British Isles
Published: 2017-11-13
Subjects: Civil and Environmental Engineering, Earth Sciences, Engineering, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Oceanography and Atmospheric Sciences and Meteorology, Other Civil and Environmental Engineering, Other Earth Sciences, Other Environmental Sciences, Other Oceanography and Atmospheric Sciences and Meteorology, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics
Ocean tide loading (OTL) affects all parts of the British Isles to varying degree, causing peak-to-peak vertical displacements of up to 13 cm in South-West England over semi-diurnal and diurnal timescales. Lateral displacements are typically around one-third of the magnitude of vertical displacements at a point, so are also considerable for carrier phase GNSS surveying. Using a recent numerical [...]
Increased ice loading in the Antarctic Peninsula since the 1850s and its effect on Glacial Isostatic Adjustment
Published: 2017-11-13
Subjects: Climate, Earth Sciences, Environmental Monitoring, Environmental Sciences, Geophysics and Seismology, Glaciology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Antarctic Peninsula (AP) ice core records indicate significant accumulation increase since 1855, and any resultant ice mass increase has the potential to contribute substantially to present-day Glacial Isostatic Adjustment (GIA). We derive empirical orthogonal functions from climate model output to infer typical spatial patterns of accumulation over the AP and, by combining with ice core records, [...]
Computationally Efficient Tsunami Modelling on Graphics Processing Units (GPU)
Published: 2017-11-13
Subjects: Applied Mathematics, Civil and Environmental Engineering, Civil Engineering, Computer Sciences, Earth Sciences, Engineering, Environmental Sciences, Geophysics and Seismology, Hydraulic Engineering, Numerical Analysis and Computation, Numerical Analysis and Scientific Computing, Other Civil and Environmental Engineering, Other Earth Sciences, Other Environmental Sciences, Physical Sciences and Mathematics
Tsunamis generated by earthquakes commonly propagate as long waves in the deep ocean and develop into sharp-fronted surges moving rapidly towards the coast in shallow water, which may be effectively simulated by hydrodynamic models solving the nonlinear shallow water equations (SWEs). However, most of the existing tsunami models suffer from long simulation time for large-scale real-world [...]