Browsing by Author "Hall, John"

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    Disdyakis Triacontahedron Discrete Global Grid System
    (2022-04) Hall, John; Samavati, Faramarz; Runions, Adam; Stefanakis, Emmanuel
    The amount of information collected about the Earth has become extremely large. With this information comes the demand for integration, processing, visualization and distribution of this data so that it can be leveraged to solve real‑world problems. To address this issue, a carefully designed information structure is needed to store all of the information about the Earth in a convenient format such that one can easily use it to solve a wide variety of problems. In this thesis, we explore the idea of creating a Discrete Global Grid System (DGGS) using a Disdyakis Triacontahedron (DT) as the initial polyhedron. We have adapted a simple, closed‑form, equal‑area projection to reduce distortion and speed up queries. We have also derived an efficient, closed‑form inverse for this projection that can be used in important DGGS queries. The resulting construction is indexed using an atlas of connectivity maps. Using some simple modular arithmetic, we can then address point to cell, neighborhood and hierarchical queries on the grid, allowing for these queries to be performed in constant time. We have evaluated the angular distortion created by our DGGS by comparing it to a traditional icosahedron DGGS using a similar projection. We demonstrate that our grid reduces angular distortion while allowing for real‑time rendering of data across the globe.
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    Resolution Adaptive Vector Rasterization in Discrete Global Grid Systems
    (2022-02-25) Mirtabatabaeipour, Amirhossein; Hall, John; Samavati, Faramarz
    Discrete Global Grid Systems (DGGS) are relatively new globe-based digital earth systems capable of integrating large geospatial datasets. In this report, we describe a new algorithm for rasterizing vector data to DGGS that relies on the hierarchical property of DGGS and adaptively changes to coarser rasterization to reach to target resolution high-resolution girds.
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    ItemEmbargo
    The Objectification of subjective experience in art
    (1982) Pyra, Gregory Michael; Hall, John