Banca de DEFESA: WENDELL SANTANA FAGUNDES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : WENDELL SANTANA FAGUNDES
DATE: 10/07/2023
TIME: 15:00
LOCAL: https://meet.google.com/vwy-ytkz-ezr
TITLE:

AVALIAÇÃO DA QUALIDADE DE DADOS ALTIMÉTRICOS “ALOS WORLD 3D – 30 m”

KEY WORDS:

Global digital elevation models; DEM; DTM; AW3D30; Alos; DEM accuracy; corrections in DEM; PE3D; GeoSampa; MapBiomas; SRTM; ASTER GDEM; TOPODATA.

PAGES: 92
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Geografia Física
SPECIALTY: Geocartografia
SUMMARY:

Digital Elevation Models (DEMs) at a global level are sources of data for several disciplines of knowledge such as hydrology, water resources, geology, geomorphology, civil engineering projects, vegetation survey, glaciology, volcanology, modeling of natural hazards, orthorectification of orbital images, irrigation projects, among others. This multifaceted use implies the search for the best global models in terms of accuracy. Therefore, the main objective of this study was to evaluate the altimetric quality and propose corrections at the national level for the digital global elevation model Alos World 3D - 30m (AW3D30), made available free of charge to the international community by JAXA (Japan Aerospace Exploration Agency). More specifically, this work evaluated correlations of the vertical errors of the AW3D30 with land use and land cover classes, derived from the MapBiomas project; applied corrections to the AW3D30 data, based on these correlations; and, finally, validated the correction methodology with the framework of the PEC-PCD (Cartographic Accuracy Standard for Digital Cartography Products) in the original and corrected MDE. In view of this, the present work shows relevance by investigating the relationship between land use and land cover and the errors inherent in the AW3D30 MDE, in addition to proposing a simple and objective corrective modeling applied to the global MDE. The materials of this study consisted of data and digital resources, namely: altimetric data that represent the field truth, coming from four sources, namely GeoSampa (Lidar data), Tridimensional Pernambuco (Lidar data), points of the Alta Altimetric Network Precision (RAAP) of the Brazilian Geodetic System and data obtained by in loco measurement methods (Positioning by GNSS); the MDE AW3D30; Classified raster of land use and land cover from the MapBiomas Platform. The methodology was structured starting with the acquisition, treatment and normalization of the aforementioned data, then errors were estimated in the MDE AW3D30 against the Lidar and GNSS reference data, statistical studies were performed to evaluate the consistency of the data and to verify the altimetric quality of the AW3D30 by MapBiomas class. Following the work established parameters of altimetric correction using an empirical modeling, this model was applied and validated in different regions. Given the exposed methodology, this study was able to build corrected AW3D30 models for three validation areas, in the states of Pernambuco, São Paulo and Bahia. The results showed a significant improvement in altimetric accuracy, measured by the RMSE, whose values increased from 8.22m, 4.06m and 1.87m before correction to 4.55m, 2.48m and 1.26m after correction, respectively, for the areas in Pernambuco, São Paulo and Bahia. The results encourage the application of the corrective methodology proposed in this study throughout the national territory, since it reduced the RMSE of the AW3D30 by 38.70%, on average, for the validation areas.

COMMITTEE MEMBERS:
Presidente - 2466669 - MAURO JOSE ALIXANDRINI JUNIOR
Interno - 2097530 - JULIO CESAR PEDRASSOLI
Externo à Instituição - MARCIO AUGUSTO REOLON SCHMIDT - UFU