Efficient terrain analysis and processing on a decomposition-based data structure

Triangulated Irregular Network (TIN) is a widely-used model for representing terrain surface, especially when the input dataset is distributed irregularly. When using TINs to represent large terrains, the major challenges are the high storage and time costs. To address these issues, we introduce a family of decomposition-based data structures, named Terrain trees family, for encoding TINs. The compact design and local analysis strategy enable the analysis and processing of large TINs on a single local machine. New terrain analysis methods, including topological analysis and morphological analysis have been developed on Terrain trees. These methods are implemented as an open-source library named Terrain trees library (TTL). Despite the highly efficient data structure, managing large TINs on local machines remains challenging, particularly for complex analyses or simulations. Mesh simplification methods are commonly applied to reduce TIN sizes to enable downstream processing. However, these simplification methods can modify the topology of the underlying terrain in an uncontrolled manner, which affects the results of terrain analysis applications. To address this issue, a topology-aware mesh simplification method based on Terrain trees is proposed. The proposed method is further accelerated by being extended to a parallel computing environment. This project also applies Terrain trees and TTL to a real-world application, the sea ice topography. Studying sea ice topography is crucial as it enhances our ability to monitor sea ice volume changes and to comprehend sea ice processes. Besides, timely and precise assessments of sea ice dynamics are critical in the context of climate change and its impacts on polar regions. TIN-based surface models are employed to represent the sea ice surface, and methods are developed for extracting important sea ice topographic features, such as density, regions without measurements, roughness, and pressure ridge structures, from TINs.