Fast and Accurate Intersections on a Sphere

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Chen, Hongyu, Ullrich, Paul A., Panetta, Julian
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866917004713132032
author Chen, Hongyu
Ullrich, Paul A.
Panetta, Julian
author_facet Chen, Hongyu
Ullrich, Paul A.
Panetta, Julian
contents We introduce a fast, high-precision algorithm for calculating intersections between great circle arcs and lines of constant latitude on the unit sphere. We first propose a simplified intersection point formula with improved speed and numerical robustness over the ones traditionally implemented in geoscience software. We then show how algorithms based on the concept of error-free transformations (EFT) can be applied to evaluate this formula within a relative error bound that is on the order of machine precision. We demonstrate that, with a vectorized and parallelized implementation, this enhanced accuracy is achieved with no compute-time overhead compared to a direct calculation in hardware floating point, making our algorithm suitable for performance-sensitive applications like regridding of high-resolution climate data. In contrast, evaluating our formula using high-precision data types like quadruple precision and arbitrary precision, or using the robust intersection computation routines from the Computational Geometry Algorithms Library (CGAL), leads to significant computational overhead, especially since these alternatives inhibit vectorization. More generally, our work demonstrates how EFT techniques can be combined and extended to implement nontrivial geometric calculations with high accuracy and speed.
format Preprint
id arxiv_https___arxiv_org_abs_2510_09892
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Fast and Accurate Intersections on a Sphere
Chen, Hongyu
Ullrich, Paul A.
Panetta, Julian
Numerical Analysis
65D18, 65G50, 65Y04, 51-04
We introduce a fast, high-precision algorithm for calculating intersections between great circle arcs and lines of constant latitude on the unit sphere. We first propose a simplified intersection point formula with improved speed and numerical robustness over the ones traditionally implemented in geoscience software. We then show how algorithms based on the concept of error-free transformations (EFT) can be applied to evaluate this formula within a relative error bound that is on the order of machine precision. We demonstrate that, with a vectorized and parallelized implementation, this enhanced accuracy is achieved with no compute-time overhead compared to a direct calculation in hardware floating point, making our algorithm suitable for performance-sensitive applications like regridding of high-resolution climate data. In contrast, evaluating our formula using high-precision data types like quadruple precision and arbitrary precision, or using the robust intersection computation routines from the Computational Geometry Algorithms Library (CGAL), leads to significant computational overhead, especially since these alternatives inhibit vectorization. More generally, our work demonstrates how EFT techniques can be combined and extended to implement nontrivial geometric calculations with high accuracy and speed.
title Fast and Accurate Intersections on a Sphere
topic Numerical Analysis
65D18, 65G50, 65Y04, 51-04
url https://arxiv.org/abs/2510.09892