1,721,003 research outputs found
Landslide monitoring with integrated techniques
No full textIn the last years, the GPS technique has become a very useful tool for the monitoring
of landslide movements. The success of this application is, of course, due to the
characteristics of GPS techniques that combine a relative easiness in the acquisition
of data with very high precision and accuracy in the measurement. Moreover, the GPS
allows an easy reconstruction of the velocity field of a landslide which adds a really
helpful information for the modelling of this kind of phenomena. The surface velocity
obtained by GPS, however, could be not really representative of the deep movements
of gravitational phenomena. This means that in the monitoring of landslides it’s not
possible to leave out of consideration the information coming from other techniques
of investigation.
In the paper are summarised the geological and geomorphological studies and the
main results of the monitoring survey carried out on some areas located in Basilicata
region (southern Italy). The landslide monitoring system is made up by traditional
survey system and new technologies.
One test site was at Lauria locality, an urbanized area interested by large and active
landslides; the lasts are subject to frequent reactivations causing severe damage to the
urban structures. The results of GPS survey, in good agreement with the results of
the geomorphologic study, show that some of the analysed landslides are subject to a
slow, continue deformations.
Other results come from the survey (in progress) about slope instability processes
observed in two different areas of the "Parco Archeologico Storico Naturale delle
Chiese Rupestri del Materano" where fine rupestrian heritages are present. In these
areas, the considerable acclivity of the slopes and the lithological defects and intense
fracturing state of carbonate rocks cause rapid mass movements of the blocks (rock
falls, topples and rockslides). On the basis of geological and geomorphological
studies, the potentially unstable carbonate blocks that need survey have been defined.
The design of the survey system is made up by a traditional topographic survey, GPS
measures and a deformation measurement system
Effects of the Orbital uncertainties on Atmosphere profiles retreived with the GNSS Radio Occultation Technique
No full textMeasurement of Dragging of Inertial Frames and Gravitomagnetic Field Using Laser-Ranged Satellites
No full textBy analysing the observations of the orbits of the laser-ranged satellites LAGEOS and LAGEOS II, using the program GEODYN, the authors have obtained the first direct measurement of the Lense-Thirring effect, or dragging of inertial frames and the first direct experimental evidence for the gravitomagnetic field. The accuracy of their measurement is of about 30%
Test of Lense-Thirring Orbital Shift Due to Spin
No full textThe Lense-Thirring effect is a very small shift of the orbit of a test particle due to the spin of a body. It may be described as al orbital drag due to the gravitomagnetic field generated by the spin of the central body. Gravitomagnetism, a fundamental weak-field prediction of Einstein's theory of general relativity, is generated by currents of mass and owes its name to its formal analogies with magnetism, generated by currents of electric charge. Then, according to general relativity, the Earth's spin should influence the motion of its orbiting satellites. Indeed, we have analysed the laser-ranging observations of the orbits of the satellites LAGEOS and LAGEOS II and have obtained the first direct measurement of the Lense-Thirring effect, or 'frame-dragging', due to the Earth's spin. We measured mu(Lense-Thirring) congruent to 1.1 and estimated the total error delta mu(Lense-Thirring) congruent to +/-0.3, whereas the general relativistic value is mu(Lense-Thirring) = 1
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