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Regional Models

Guayaquil - Ecuador (GEOID-GUAYAQUIL2019)


  Authors: I.F. Palacios Orejuela, C.A. Leiva González     Created: 2019    Resp: I.F. Palacios Orejuela  
      Status: PUBLIC    

Description:
The GEOID-GUAYAQUIL2021 model for the rural area of the Guayaquil Canton in Ecuador was calculated by the Universidad de las Fuerzas Armadas ESPE, Sangolquí, Ecuador. It is based on a non-conventional technique, such as Cokriging (Goovaerts, 1997), through the combination of GPS data/differential leveling and a densely sampled auxiliary variable. The GPS satellite positioning was performed using the Static Differential method through dual-frequency receivers in each point; regarding the level heights they were obtained by second-level differential leveling. The geoid undulation from the EGM2008 model with spatial resolution of 1 arc min was proposed as an auxiliary variable for the interpolation of geodetic undulation in combination with dispersed GPS data (Odera and Fukuda, 2015). Ordinary, Residual and Universal Cokriging and Kriging techniques were used and their results were compared to select the best for achieving accuracy. In particular, a “split-off” validation was performed by excluding a subset of data, repeating the processing, and then comparing the results with the one obtained with the full dataset. This validation yielded that the solution based on Universal Cokriging was the most accurate with an RMSE of 8 cm and RSR of 0.0282, obtained just with 66 samples (20% of the dataset). This model is presented as a practical alternative for obtaining level heights for various geoscience applications.

Model Citation:
I.F. Palacios Orejuela, C.A. Leiva González (2019). The geometric geoid of Guayaquil Canton: GEOID-GUAYAQUIL2019. V. 1.0. GFZ Data Services. DOI: 10.5880/isg.2019.019

Reference:
I.F. Palacios Orejuela, C.A. Leiva González, X. Buenaño Guerra, E. Chicaiza Mora, T. Toulkeridis (2021). Geoid undulation modeling through the Cokriging method - A case study of Guayaquil, Ecuador. Geodesy and Geodynamics, 12(5), pp. 356-367. DOI: 10.1016/j.geog.2021.04.004

Digital object identifier:
DOI: 10.5880/isg.2019.019 (geoid in ISG format)

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