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Determinação e análise das principais componentes de maré terrestre e de carga oceânica, por meio de dados de posição e do campo de gravidade terrestre
| Content Provider | Semantic Scholar |
|---|---|
| Author | Abreu, Mário Alexandre De |
| Copyright Year | 2019 |
| Abstract | The Earth suffers deformations due to the gravitational attraction of the celestial bodies and to the redistribution of water mass occurring by the action of the ocean tide. These effects are known as solid Earth tide and ocean tide loading, and can be estimated by observations of the amplitudes and phases of their tidal wave constituents. The conventional way of investigating such phenomena is through gravimetric observations. However, with the development of methods of data acquisition, nowadays it is possible to measure these effects using GNSS (Global Navigation Satellite System) observations. The objective of this research was to estimate and analyze the amplitudes and phases of the 11 principal wave constituents of solid Earth tide and ocean tide loading, through the analysis of the variations in terrestrial gravity field measured using gPhone, and position variations using GPS (Global Positioning System) observations. First, the principal constituents of solid Earth tide were analyzed, based on gravimetric observations and GPS positioning, using data collected at stations installed in Manaus and Brasília, Brazil, resulting in the estimation of amplitude and phase for the long period, monthly, diurnal and semidiurnal constituents, besides determining the time required for the convergence of the estimated constituent values. The estimated amplitude and phase values, using gravimetric data, converged between the 2 and 6 months of the time series. For the positioning observations, the constituents values converged between the 2 and 17 month of the data series, except for the long period constituent, which requires a longer time series to obtain satisfactory values for both methods. The results show that the solid Earth tide constituents were better estimated by the gravimetric data compared to the positioning data considering the series analyzed. Secondly, this research aims to analyze the amplitudes and phases of the 11 principal wave constituents of solid Earth tide and ocean tide loading, using GPS observations collected at stations located in Belém, Brasília, Eusébio, Manaus and Santa Maria, Brazil. In this way, the amplitude and phase values for the evaluated constituents were estimated, as well as the convergence values for these constituents. The results showed that the great majority of the estimated constituents presented convergence during the analyzed period of time. In addition, the time series were corrected for the effects of solid Earth tide and ocean tide loading, first using the calculated parameters, and later using the theoretical models. Comparing the results, it was possible to suggest that the two solutions presented similar behavior, validating the use of GPS observations in the estimation of tidal wave constituents. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://repositorio.unb.br/bitstream/10482/36084/1/2019_M%C3%A1rioAlexandredeAbreu.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
