Determination of gravity anomalies in Java, Indonesia, from airborne gravity survey

Bramanto, Brian; Prijatna, Kosasih; Pahlevi, Arisauna Maulidyan; Sarsito, Dina A.; Dahrin, Darharta; Variandy, Erfan Dany; Munthaha, R. I. S.

doi:10.3319/tao.2021.06.04.01

Cited by 3 publications

(2 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To improve the quality of the geoid model, the Geospatial Agency of Indonesia (BIG) began to measure a completely new gravity dataset through terrestrial gravity measurements with a sampling interval of every 5 km in several major cities (Syafarianty et al 2021). In addition, BIG also deployed several airborne gravity measurements (Pahlevi et al 2015(Pahlevi et al , 2019Bramanto et al 2021) since the last decade. As a result, the new gravity dataset covers all primary islands in Indonesia, and the time has come to determine the Indonesia geoid model.…”

Section: Introductionmentioning

confidence: 99%

Gravimetric Geoid Modeling by Stokes and Second Helmert’s Condensation Method in Yogyakarta, Indonesia

Bramanto

Prijatna

Fathulhuda

et al. 2022

International Association of Geodesy Symposia

Self Cite

View full text Add to dashboard Cite

Since the last decade, Indonesia has continuously improved the accuracy of the national geoid model by conducting rapid gravity acquisition using airborne and terrestrial gravimetry. As gravity data have been collected thoroughly in all regions, the time has come to carry out Indonesia’s geoid modeling. We started our study by employing the Stokes and Second Helmert’s condensation method to our terrestrial gravity data in Yogyakarta, Indonesia, with a target area of 1∘× 1∘. The computation was based on the commonly applied remove-compute-restore process. We used a satellite-only geopotential model of GO_CONS_GCF_2_TIM_R6 up to degree 300 to remove and restore the long-wavelength part of the gravity field within the modeling process. Numerical results show that few cm of geoid model accuracy was achieved when we compared it to the validation points. Also, our best performance geoid is estimated to be better than the Earth Gravitational Model 2008 (EGM2008) geoid model by up to 2.8 cm in terms of standard deviation.

show abstract

Section: Introductionmentioning

confidence: 99%

Gravimetric Geoid Modeling by Stokes and Second Helmert’s Condensation Method in Yogyakarta, Indonesia

Bramanto

Prijatna

Fathulhuda

et al. 2022

International Association of Geodesy Symposia

Self Cite

View full text Add to dashboard Cite

show abstract

“…Normal gravity is also known as the latitude correction. Its correction varies as a function of latitude caused by the centrifugal acceleration [Bramanto et al, 2021].…”

mentioning

confidence: 99%

Gravity data reduction, Bouguer anomaly, and gravity disturbance

Nazan

2023

View full text Add to dashboard Cite

Each point on the earth has a gravity and gravity potential value. Surfaces formed by connecting points with equal gravity potential values are called equipotential surfaces or level surfaces. Determination of gravity field of the earth and the geoid which is one of the earth’s equipotential surfaces is very important for physical geodesy. Gravity values measured on the physical earth are not directly included in studies; firstly, they must be converted into gravity anomalies. For this, in this study precise leveling, gravity and GPS measurements were made in the field. Heights (H) with precise leveling measurements, gravity values (g) with gravity measurements and geographical latitudes (j) with GPS measurements were recorded. Then, gravity reductions (free-air, Bouguer) were calculated at the points. The actual gravity g measured on Earth is not immediately directly comparable to the normal gravity of the ellipsoid surface. Gravity values must be reduced to the geoid. Since there are masses outside the geoid, reduction methods differ according to the way these topographic masses are handled. Bouguer gravity anomalies and gravity disturbances are derived. The gravity anomaly (Dg) is defined as the scalar difference between the Earth’s gravity on the geoid and normal gravity on the surface of the reference ellipsoid. Gravity disturbance (dg) is defined as the difference between the actual gravity magnitude measured on Earth and its equivalent normal gravity in the normal gravity field for the same point. The changes and magnitudes of the calculated quantities are compared. Changes such as the observed gravity and height data, observed gravity changes versus calculated normal gravity changes, normal gravity on ellipsoid versus geographic latitude, observed gravity changes versus latitude changes, Bouguer gravity anomaly and gravity disturbance versus latitude and elevation, free-air reduction and Bouguer gravity reduction versus latitude and elevation have been investigated.

show abstract

Geoid Undulation Model as Vertical Reference in Indonesia

Pahlevi,

Syafarianty,

Susilo

et al. 2024

Sci Data

View full text Add to dashboard Cite

Indonesia released a new regional geoid model in 2020—the Indonesian Geoid 2020 (INAGEOID2020). It covers the Indonesian region with a spatial resolution of 0.01 × 0.01 degree with the unit in meters. The model was generated through a series of data and computations. Three components of gravity data, i.e., the observed free-air anomaly, the long-wave from the global geoid model, and the short-wave from the terrain model, were employed. The computation was performed using the Remove-Compute-Restore technique with the Fast Fourier Transformation approach. The output was then fitted to the geoid at tide stations by adding a fitting plane to the geoid model. The fitting plane was constructed based on the difference between the geoid model and each tide gauge benchmark. The final geoid model was evaluated by comparing the model with the reference data. Based on quality metrics, the accuracy of INAGEOID2020 varied between 6 cm to 29 cm. Any interested user can use this gridded geoid model to convert geodetic to orthometric heights and vice versa.

show abstract

Determination of gravity anomalies in Java, Indonesia, from airborne gravity survey

Cited by 3 publications

References 44 publications

Gravimetric Geoid Modeling by Stokes and Second Helmert’s Condensation Method in Yogyakarta, Indonesia

Gravimetric Geoid Modeling by Stokes and Second Helmert’s Condensation Method in Yogyakarta, Indonesia

Gravity data reduction, Bouguer anomaly, and gravity disturbance

Geoid Undulation Model as Vertical Reference in Indonesia

Contact Info

Product

Resources

About