Using Particle Swarm Optimization to Establish a Local Geometric Geoid Model

Kao, Szu-Pyng; Ning, Fang-Shii; Chen, Chao-Nan; Chen, Chia‐Ling

doi:10.1590/s1982-21702017000200021

Cited by 11 publications

(4 citation statements)

References 18 publications

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“…The residual and the total number of selected points are used for the computation of the RMSE, as well as the accuracy of the geometric geoid model. The Root Mean Square Error, RMSE index for the computation of the geometric geoid model accuracy as given by Kao et al (2017) METHODOLOGY The adopted methodology was divided into different stages such as data acquisition, data processing, and results presentation and analysis. Figure 2 shows the adopted methodology flow chart.…”

Section: Accuracy Of Geometric Geoid Modelmentioning

confidence: 99%

Relationship between Polynomial Geometric Surfaces Terms and Observation Points Numbers and Effect in the Accuracy of Geometric Geoid Models

Eteje¹,

Oduyebo²,

Oluyori³

2019

IJEAB

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The application of the geometric method of local geoid model determination which requires the fitting of geometric surfaces to known geoid heights to enable geoid heights of new points to be interpolated involves the use of least squares technique for computation of the models' parameters. The selection of polynomial geometric surfaces depends on the size of the study area, the variation of the geoid heights and the number of measurement points. The accuracy of the geometric geoid model increases as the number of observation points approximates the number of geometric surface terms. But in most cases, the number of observation points is not considered. To this effect, this paper presents the relationship between geometric surfaces terms and observation points numbers and effect in the accuracy of geometric geoid models. A total of 23 points of known local gravimetric geoid heights were used. Two polynomial geometric (third and fifth degrees) surfaces were fitted to the geoid heights at various observation point numbers and compared to determine the relationship between the number of model terms and that of observation points and effect in the accuracy of the models. Least squares adjustment technique was applied to obtain the model parameters. The differences between the models and the known geoid heights of the points were computed and used to obtain the RMSEs as well as the accuracy of the models. The obtained results showed that the accuracy of the polynomial geometric geoid models tends to the highest as the number of measurement points approximates the number of the model terms and in a unique solution where the number of observation points is equal to the number of the polynomial geometric model terms, the model accuracy is highest. The paper recommends that the geometric method of local geoid model determination should be strictly applied in small areas. Where the method will be applied in considerable large areas, higher degrees polynomial geometric surfaces with a larger number of terms approximating the number of observation points should be applied. This will enable a proper fit of the polynomial surface to the known geoid heights, as well as high accuracy to be obtained.

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Section: Accuracy Of Geometric Geoid Modelmentioning

confidence: 99%

Relationship between Polynomial Geometric Surfaces Terms and Observation Points Numbers and Effect in the Accuracy of Geometric Geoid Models

Eteje¹,

Oduyebo²,

Oluyori³

2019

IJEAB

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“…The combined topographic effect was computed using equation (11). The final local gravimetric geoid model of the study area was obtained by finding the mean of the precise geoid heights of the points using equation (12). The spirit levelling of the validation points was reduced using the height of instrument method, as well as collimation method.…”

Section: Data Processingmentioning

confidence: 99%

Practical Local Geoid Modelling of Benin City, Nigeria from Gravimetric Observations Using the Modified Stokes Integral

Oduyebo¹,

Ono²,

Eteje³

2019

IJAEMS

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The geometric heights obtained from GNSS observations cannot be used for engineering works as they are not reduced to the geoid. This study presents practical local geoid modelling from gravimetric observations using the modified Stokes integral for engineering applications in Benin City. A total of 52 points were observed with GNSS receivers and a gravimeter to respectively obtain their positions and absolute gravity values. The theoretical gravity values of the points were computed on the Clarke 1880 ellipsoid to obtain their local gravity anomalies. The modified Stokes integral was applied to compute the geoid heights of the points. The combined topographic effect was applied to the computed geoid heights of the points to obtain their precise geoid heights. The mean of the precise geoid heights of the points was computed to obtain the local gravimetric geoid model of the study area. The determined geoid model was validated for its reliability as well as the accuracy using the RMSE index. It is recommended that the use of assumed, as well as handheld GPS receiver heights for engineering works should be totally abolished as this study has established the local geoid model of Benin City.

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“…The geometric geoid model geoidal undulations are compared with the known geoidal undulations of the points to obtain the residuals. The Root Mean Squares Error, RMSE index for the computation of geometric geoid model accuracy as given by Kao et al (2017) is…”

Section: Ax L =mentioning

confidence: 99%

Local Geometric Geoid Models Parameters and Accuracy Determination Using Least Squares Technique

Okiemute¹,

Olujimi²

2018

ijird

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Using Particle Swarm Optimization to Establish a Local Geometric Geoid Model

Cited by 11 publications

References 18 publications

Relationship between Polynomial Geometric Surfaces Terms and Observation Points Numbers and Effect in the Accuracy of Geometric Geoid Models

Relationship between Polynomial Geometric Surfaces Terms and Observation Points Numbers and Effect in the Accuracy of Geometric Geoid Models

Practical Local Geoid Modelling of Benin City, Nigeria from Gravimetric Observations Using the Modified Stokes Integral

Local Geometric Geoid Models Parameters and Accuracy Determination Using Least Squares Technique

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