Refinamento do modelo geoidal brasileiro para o sul do estado de Santa Catarina

• Autor(a) principal: Silveira, Leonard Niero da
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Manancial - Repositório Digital da UFSM
• dARK ID: ark:/26339/0013000010xqg
• Texto Completo: http://repositorio.ufsm.br/handle/1/29323
• topic: Nivelamento; Altitude ortométrica; Altitude elipsoidal; Altura geoidal; Krigagem; Leveling; Orthometric height; Ellipsoidal eight; Geoidal height; Kriging; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS

The developed work shows a methodology for the correction and consequently, the refinement of the values of the Brazilian geoidal model, using the geometrical geodesy as tool for the minimization of on inherent problem in physical geodesy, having as a study southern region of State of Santa Catarina. It was located in the region, apexes of the net of geometrical leveling the was introduced by the Brazilian Institute of Geography and Statistic - IBGE and it was entranced, through the constituent constellations of the GNSS, the ellipsoidal heights originating from the net of geodetic Brazilian reference (Brazilian Net of Continuous Observing and geodetic state planimetric net). The difference between the elipsoidal height and the orthometric height for each reference of level getting itself the value of the undulations of geoid for each place. Deducting these values from the extracted geoidal height of the Brazilian geopotential model MapGeo2004, the values of the differences had been gotten where a model of correction by means of the geoestatistic technique of esteem values of the kriging was generated, except eleven references of level that they had constituted the points of control for the evaluation of the final model. The result of the geoestatistic treatment was a coefficient of correlation of Pearson of 0,998, in other words, a degree of rightness of 99,8% in the esteem of the values. A model of the Brazilian geoidal map in the south of Santa Catarina was generated extracting the values of the geoidal height, creating a mesh with amplitud of 30” x30” of arc, having the coincident values of grating with the values of the grating of the correction model. It was applied a correction to the Brazilian geoidal model getting a precision of 0,008 m against 0,627 m of the previous model. To ratify the reached result, one compared the values of the fine model with models MapGeo2010, EGM96 and EGM2008. It was verified that the fine model is coming close to the values of the EGM2008, with average difference of 0,123 m. Also it was carried through a geometric leveling with origin and closing in a level reference, carrying through the transport of the ortometric heights for two points tracked with technique GNSS and calculated ortometric heights from the fine model, the difference between the two methods was of -0,0018 m and 0,0047 m for colon respectively, ratifying the reached results.