Descripción del proyecto
Modelos avanzados de orientación podrían ayudarnos a navegar con una precisión subcentimétrica sin precedentes
La dependencia de la rotación de la Tierra para la cronometría y la navegación ha dado paso a tecnologías más avanzadas, como los relojes atómicos y el GPS, que ofrecen mayor precisión. El GPS se basa en dos marcos de referencia: el terrestre, fijo con respecto a la Tierra, y el celeste, inmóvil en el espacio. Sin embargo, las redistribuciones de masa y la fuerza gravitacional del Sol y la Luna pueden provocar irregularidades en la rotación y orientación de la Tierra. Los geodestas y los geofísicos utilizan observaciones para medir estos cambios, además de técnicas como la precesión y la nutación para mejorar los modelos de orientación de la Tierra. El equipo del proyecto RotaNut, financiado por el Consejo Europeo de Investigación, mejorará los modelos de orientación de la Tierra a un nivel subcentimétrico al identificar la física adicional del interior de nuestro planeta y los mecanismos de acoplamiento en los límites del núcleo líquido.
Objetivo
The rotation of the Earth has long been used as a measure of time, and the stars as reference points to determine travellers’ whereabouts on the globe. Today, precise timescales are provided using atomic clocks and precise positioning is determined using geodetic techniques such as GPS grounded on two reference frames: the terrestrial frame, fixed relative to the Earth and rotating synchronously with the planet, and the celestial frame, which is immobile in space, where the artificial satellites such as those of GPS are moving. The relationship between these frames is complicated by the fact that the rotation and orientation of the Earth is subject to irregularities induced by global mass redistributions with time and external forcing such as the gravitational pull of the Sun and the Moon. With the advance of observation precision, the causes of Earth orientation changes are progressively being identified by geodesists and geophysicists. The term ‘precession’ describes the long-term trend of the orientation of the axis of spin, while ‘nutation’ is the name given to shorter-term periodic variations, which are the prime focus of the present project. The rotation axis of the Earth is moving in space at the level of 1.5km/year due to precession and has periodic variations at the level of 600 meters as seen from space in a plane tangent to the pole. The present observations allow scientists to measure these at the sub-centimetre level enabling them to identify further physics of the Earth’s interior to be taken into account in the Earth orientation models such as the coupling mechanisms at the boundary between the liquid core and the viscoelastic mantle, as well as many other factors (sometimes not yet definitely identified). The proposed research will address many of these and will result in the development of improved global orientation of the Earth with an unprecedented accuracy - at the sub-centimetre level.
Ámbito científico
- natural sciencesphysical sciencesastronomyobservational astronomyradio astronomy
- natural sciencesphysical sciencesastronomyplanetary sciencesplanets
- natural sciencesphysical sciencesastronomyplanetary sciencesnatural satellites
- natural sciencesearth and related environmental sciencesgeophysics
- natural sciencesmathematicspure mathematicsmathematical analysisdifferential equationspartial differential equations
Programa(s)
Régimen de financiación
ERC-ADG - Advanced GrantInstitución de acogida
1180 Bruxelles / Brussel
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