Offset Evaluation of the Ecuadorian Vertical Datum Related to the Ihrs

Sánchez, José L. Carrión; Freitas, Sílvio Rogério Correia de; Barzaghi, Riccardo

doi:10.1590/s1982-21702018000400031

Cited by 3 publications

(1 citation statement)

References 23 publications

(25 reference statements)

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“…Researchers have proposed several approaches in several countries and regions around the world for more than three decades. Among them, some of the most widely used can be mentioned: the approach based on the mean of the discrepancies between height anomalies (Kasenda 2009;Grombein, Seitz & Heck 2017); the approach based on the zero-level geopotential values (Burša et al 1999;De Freitas 2015;Sánchez, De Freitas & Barzaghi 2018;Ihde et al 2017); and the approach based on the GBVP solution (Rummel & Teunissen 1988;Xu 1992;Gerlach & Rummel 2012;Amjadiparvar, Rangelova & Sideris 2016;Grombein, Seitz & Heck 2016;Zhang et al 2020).…”

Section: Palavras-chave: Altitudes Normais Brasileiras; Modelo Global...mentioning

confidence: 99%

Linkage of Normal Heights Obtained from GNSS and Refined XGM2019 GGM to Brazilian Vertical Data Using Different Approaches

Delgado

Rodrigues

2023

Anu. Inst. Geociênc.

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This work aimed to analyze the use of different approaches to link normal heights obtained via Global Navigation Satellite System (GNSS)/Global Geopotential Model (GGM) refined by the RTM technique to the Brazilian Vertical Data (Imbituba Brazilian Vertical Datum – IBVD and Santana Brazilian Vertical Datum – SBVD). Specifically, it analyzed approaches based on the weighted mean of discrepancies between height anomalies, the zero- level geopotential value, the Geodetic Boundary Value Problem (GBVP) solution, and the use of parametric modeling of a plane with a scale factor. For the numerical tests, two different study regions have been used, the first with heights referenced to IBVD and the second to SBVD. Using the first three approaches, the local modeling idea has been investigated in both regions. In this context, spatial cluster analysis of the outliers of differences between local and global height anomalies defined the sub-regions. In the fourth approach, the treatment of local modeling was initially considered. In the accuracy analysis of linkages, it has been verified that approaches based on the mean of the discrepancies between height anomalies and using zero- level geopotential value propose practically the same results. On the other hand, there were improvements at the centimeter level with the use of the GBPV solution-based approach compared to the first two, except for two worsening cases. With the approach based on parametric modeling, the accuracy results were mainly worse considering the approaches with local modeling. The most significant differences reached the decimeter level.

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Section: Palavras-chave: Altitudes Normais Brasileiras; Modelo Global...mentioning

confidence: 99%

Linkage of Normal Heights Obtained from GNSS and Refined XGM2019 GGM to Brazilian Vertical Data Using Different Approaches

Delgado

Rodrigues

2023

Anu. Inst. Geociênc.

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On the connection of the Ecuadorian Vertical Datum to the IHRS

Carrión

Freitas

Barzaghi

2023

Journal of Geodetic Science

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In this work, the determination of the discrepancy between the Ecuadorian Vertical Datum (EVD) and the International Height Reference System (IHRS) is presented. The vertical offset was estimated at the EVD based on the fixed geodetic boundary value problem approach. The focus of the experiment was the determination of the anomalous potential in the EVD, which in turn enable determination of the respective geopotential value. Taking a geopotential space-based approach, two estimates of the EVD offset with respect to the IHRS were obtained that amount to −1.51 and −1.61 m2/s2.

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Global Geopotential Models assessment in Ecuador based on geoid heights and geopotential values

Carrión,

Flores,

Rodríguez

et al. 2023

Journal of Geodetic Science

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Since the 1960s, the analysis of disturbed satellite orbits to infer Earth’s gravity field functionals has been an important element in determining the Earth’s gravitational field. The long wavelengths of the gravitational field are recovered through the analysis of non-Keplerian variations in the orbital path of artificial satellites, from their tracking from ground stations (Satellite Laser Ranging, Doppler Orbitography and Radiopositioning Integrated by Satellite, and Precise Range And Range-Rate Equipment), from satellite-to-satellite tracking, or by microwave interferometry. In addition, differences in gravitational acceleration in three mutually orthogonal dimensions can be determined by employing a differential accelerometer carried on artificial satellites (satellite gravity gradiometry, SGG). Satellite gravimetry provides global information (long wavelengths) of the Earth’s gravitational field, which is the fundamental basis for the implementation of Global Geopotential Models (GGMs). The GGMs are one of the key tools for the representation of the Earth’s gravity field and, therefore, for the establishment of a Global Height System (i.e., International Height Reference System), whose fundamental reference surface is defined in terms of a geopotential value. In this study, the validation of high-resolution GGMs (coefficients up to degree 2190) was performed based on their performance in Ecuador by comparing geoid heights estimated by the GGMs with the corresponding values derived from Global Navigation Satellite System/leveling records. Furthermore, geopotential values from the GGMs are compared with the corresponding value obtained for the Ecuadorian Vertical Datum by solving the fixed geodetic boundary value problem. The obtained results indicated that the precision of the high-resolution GGMs does not reach the established requirements for the geopotential computation in the International Height Reference Frame fundamental stations.

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Offset Evaluation of the Ecuadorian Vertical Datum Related to the Ihrs

Cited by 3 publications

References 23 publications

Linkage of Normal Heights Obtained from GNSS and Refined XGM2019 GGM to Brazilian Vertical Data Using Different Approaches

Linkage of Normal Heights Obtained from GNSS and Refined XGM2019 GGM to Brazilian Vertical Data Using Different Approaches

On the connection of the Ecuadorian Vertical Datum to the IHRS

Global Geopotential Models assessment in Ecuador based on geoid heights and geopotential values

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