Contribution to the Establishment of the IHRF in the State of São Paulo

Ribeiro, Leticia Cristina; Guimarães, Gabriel do Nascimento; Camargo, Paulo de Oliveira

doi:10.1109/lgrs.2021.3071254

Cited by 3 publications

(2 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The results showed an inverse behavior increasing the discrepancies of different order and degree, suggesting a trend in the terrestrial gravity data or on the DTM. On the other hand, studies carried out by Ribeiro et al (2021) for the PPTE, used the GOCO05C model developed up to nmax: 250, without application of the RTM, showed 0.470 m 2 s -2 or 5 cm of difference, considering the performance of the IHRF with degree and order 200.…”

Section: Disturbing Potential Differences Of the Numerical Integratio...mentioning

confidence: 96%

Computation and Analysis of Geopotential Number in São Paulo, Brazil

et al. 2022

View full text Add to dashboard Cite

In recent decades, important steps have been taken to implement the physical concepts of Geodesy in practice, con- cerning height systems. Despite the difficulties involving gravity field modeling, with the establishment of conventions, standards, and computation strategies, the realization of the International Height Reference System (IHRS) is well underway. For a global system, there are constraints for some countries, especially for those with sparse gravity data, mountain regions, and vast areas. In terms of methodology, the computation can be performed directly using the Global Geopotential Models (GGM), recovering existing geoid models, or determining pointwise the gravity potential using integral formulas. In general, the regional gravity modeling is given by numerical integration or least-squares collocation and more recently adopting the spherical radial basis functions. The first approach allows determining the earth’s gravity component at a specific point and adjusting the integral formula according to the gravity coverage. Since so far there is no common sense about the best methodology, computation strategies are been analyzed. In this con- text, the paper aims to contribute to IHRF, computing the geopotential number in the scope of IHRF, using numerical integration to solve the Geodetic Boundary Value Problem and an existing recent quasi-geoid model in four stations in São Paulo state, Brazil. The first approach was performed considering two cases: a radius of 210 km and 110 km of gravimetric data coverage and the Global Geopotential Model GOCO05S truncated at 100 and 200, respectively. The results between solutions have shown a maximum difference of 94 cm, and a minimum difference of 10 cm.

show abstract

Section: Disturbing Potential Differences Of the Numerical Integratio...mentioning

confidence: 96%

Computation and Analysis of Geopotential Number in São Paulo, Brazil

et al. 2022

View full text Add to dashboard Cite

show abstract

“…To achieve this, a computational experiment was conducted over two years, using the same input data and different processing strategies. In South America, some experiments related to the IHRF have also been performed (Guimarães et al, 2022;Guimarães et al, 2021;Ribeiro et al, 2021Ribeiro et al, , 2023Silva et al, 2022;Tocho et al, 2022).…”

Section: Figmentioning

confidence: 99%

Connecting the Local Vertical Data in South America to the IHRF

Guimarães,

de Matos,

Blitzkow

2024

Preprint

View full text Add to dashboard Cite

Since 2015, the scientific community has been working on unifying the global vertical datum, following the resolution for the definition and realization of an International Height Reference System. One of the main goals of the task is to determine the vertical offset between the local vertical datum and the global one. This paper aims to estimate the vertical offset in seven countries (Argentina, Brazil, Chile, Colombia, Ecuador, Venezuela, and Uruguay) in South America. For this purpose, geoid (and quasi-geoid) models were computed based on the Geodetic Boundary Value Problem Solution. The technique of removing and restoring the gravity field’s long wavelengths was applied. Terrestrial gravity data and satellite gravity anomalies (in the ocean) were combined with a global geopotential model and a digital terrain model to estimate the geopotential values and compute geoid undulations. GNSS/leveling data were used to infer the geoid (quasi-geoid) models and four global geopotential models. Regarding the vertical offset, GNSS/leveling data and the geoid undulations were used in the computation. A parametric model was used to minimize random and systematic errors in the calculation process. The resultsshowed that the vertical offset varies from 0.293 m (Talcahuano tide gauge - Chile) to 1.689 m (Santana tide gauge - Brazil).

show abstract