Comparison of Helmert and rigorous orthometric heights over Japan

Odera, Patroba Achola

doi:10.1186/s40623-015-0194-2

Cited by 8 publications

(6 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3c) because most GPS/levelling data have low elevations (<1000 m) even in mountainous areas like central Honshu (e.g. Odera and Fukuda 2015). It is also noted that GOCE GGMs perform relatively better in Kyushu (considering the magnitude of standard deviation) than other regions over Japan (Figs.…”

Section: Resultsmentioning

confidence: 95%

Evaluation of GOCE-based global gravity field models over Japan after the full mission using free-air gravity anomalies and geoid undulations

Odera

2017

Earth Planets Space

Self Cite

View full text Add to dashboard Cite

The performance of Gravity field and steady-state Ocean Circulation Explorer (GOCE) global gravity field models (GGMs), at the end of GOCE mission covering 42 months, is evaluated using geoid undulations and free-air gravity anomalies over Japan, including six sub-regions (Hokkaido, north Honshu, central Honshu, west Honshu, Shikoku and Kyushu). Seventeen GOCE-based GGMs are evaluated and compared with EGM2008. The evaluations are carried out at 150, 180, 210, 240 and 270 spherical harmonics degrees. Results show that EGM2008 performs better than GOCE and related GGMs in Japan and three sub-regions (Hokkaido, central Honshu and Kyushu). However, GOCE and related GGMs perform better than EGM2008 in north Honshu, west Honshu and Shikoku up to degree 240. This means that GOCE data can improve geoid model over half of Japan. The improvement is only evident between degrees 150 and 240 beyond which EGM2008 performs better than GOCE GGMs in all the six regions. In general, the latest GOCE GGMs (releases 4 and 5) perform better than the earlier GOCE GGMs (releases 1, 2 and 3), indicating the contribution of data collected by GOCE in the last months before the mission ended on 11 November 2013. The results indicate that a more accurate geoid model over Japan is achievable, based on a combination of GOCE, EGM2008 and terrestrial gravity data sets.

show abstract

Section: Resultsmentioning

confidence: 95%

Evaluation of GOCE-based global gravity field models over Japan after the full mission using free-air gravity anomalies and geoid undulations

Odera

2017

Earth Planets Space

Self Cite

View full text Add to dashboard Cite

show abstract

“…(10) In addition, several studies to determine the rigorous orthometric heights and the practical possibility of replacing the use of Helmert orthometric heights with normal orthometric heights were carried out. (11)(12)(13) In Korea, a precision calculation of orthometric height by orthometric correction was performed mainly through leveling and gravity surveying data measured at national control points. (14,15) Various orthometric corrections were calculated in mountainous areas by using the existing gravity data or actual measured gravity data, and then the orthometric height was determined.…”

Section: Introductionmentioning

confidence: 99%

Orthometric Corrections Using Gridded Gravity Data Derived from Digital Elevation Model

Lee¹,

Kim²,

Woo³

et al. 2022

Sensors and Materials

View full text Add to dashboard Cite

In this study, gridded gravity data (GGD) were generated by using the correlation between gravity and the height extracted from a high-resolution digital elevation model (DEM) in an area where the national control points where gravity was measured are not densely distributed. Comparison of the measured gravity and the gravity generated by using GGD, which is produced by the linear regression analysis of the height extracted from DEM at the national control points, revealed that the accuracy of GGD is about 33 mGal. The difference is very small at about 4 and 5 mm, when comparing the orthometric correction for each section and the cumulative orthometric correction calculated using the gravity interpolated from GGD with the results calculated from the measured gravity, respectively. Thus, it is considered that the orthometric correction can be effectively calculated by using the gravity interpolated from GGD at the points where there are no measured gravity data. If the gravity distribution measured at national control points becomes dense, it is expected to further improve the accuracy of the gravity interpolated from the GGD, which is generated by using the linear correlation between the gravity and the height extracted from high-resolution DEM.

show abstract

“…En términos prácticos, para trabajos de ingeniería, se considera el nivel medio del mar como una superficie equivalente al geoide. Por ende, a la altura nivelada y la altura ortométrica respectivamente se las puede considerar de la misma forma (Odera & Fukuda, 2015). La determinación de alturas sobre el nivel medio del mar (niveladas) es llevada a cabo a través de campañas de nivelación geométrica que recorren las vías estatales del país y que constituyen la RCBV (Figura 1).…”

Section: Introductionunclassified

Obtención de alturas niveladas mediante nivelación GPS Caso de estudio: Morona – Ecuador

Orejuela

Pérez

2022

Uniciencia

View full text Add to dashboard Cite

El objetivo del estudio fue demostrar la aplicabilidad de la nivelación GPS para la obtención de alturas niveladas precisas con fines de ingeniería, en el cantón Morona – Ecuador. Se evaluaron dos escalas de trabajo: cantonal (macro) y urbana (micro), donde los vértices conocidos desde los cuales se arrastró el valor de altura fueron los puntos pertenecientes a la red geodésica local del cantón. Con el análisis del gradiente de ondulación geoidal se definieron 5 zonas homogéneas de variación del gradiente; se aplicó nivelación GPS en las dos zonas (zona 4 y 5) que contaban con vértices geodésicos y que además abarcan mayor superficie del cantón. Los valores del gradiente de ondulación geoidal en el área de estudio reflejan una variabilidad considerable, con errores de hasta 24 mm/Km. A escala cantonal se alcanzaron errores entre 12.19 cm – 1.27 cm a 30 Km – 5.1 Km en la zona 4, y 38.48 cm – 8.33 cm a 13 Km – 2.7 Km en la zona 5; mientras que, a escala urbana se hallaron errores de 2.48 cm – 0.14 cm a 1.07 Km – 0.19 Km respectivamente. Mediante nivelación GPS se alcanzan resultados auspiciosos para trabajos de ingeniería y las geociencias en general que necesitan alturas niveladas de forma rápida y precisa. Además, para la correcta aplicación de esta técnica se deben considerar dos determinantes que son la distancia de línea base y el gradiente de ondulación geoidal.

show abstract

Comparison of Helmert and rigorous orthometric heights over Japan

Cited by 8 publications

References 8 publications

Evaluation of GOCE-based global gravity field models over Japan after the full mission using free-air gravity anomalies and geoid undulations

Evaluation of GOCE-based global gravity field models over Japan after the full mission using free-air gravity anomalies and geoid undulations

Orthometric Corrections Using Gridded Gravity Data Derived from Digital Elevation Model

Obtención de alturas niveladas mediante nivelación GPS Caso de estudio: Morona – Ecuador

Contact Info

Product

Resources

About