LIGHTHOUSE: Fast and precise distance to shoreline calculations from anywhere on earth

2025-06-23

AI Summary

Existing global coastline datasets suffer from low spatial resolution (1–4 km), rendering them inadequate for real-time, high-precision applications such as environmental monitoring and urban planning. To address this limitation, we introduce the first globally consistent 10-meter-resolution coastline dataset. We propose a hierarchical iterative geospatial search algorithm and design Lighthouse—a lightweight, CPU-efficient query engine that synergistically integrates satellite remote sensing and computer vision techniques. Leveraging a multi-level geospatial indexing structure, Lighthouse achieves millisecond-scale, high-accuracy distance computation from any arbitrary location to the nearest coastline, using only one CPU core and 2 GB of RAM. Compared to conventional datasets, our approach improves spatial accuracy by over two orders of magnitude while drastically reducing computational overhead. This marks the first instance of globally scalable, real-time online inference for coastline proximity queries.

Technology Category

• Search and Optimization: Distributed Search
• Computer Vision: Remote Sensing / Geospatial AI
• Planning, Routing, and Scheduling: Optimization of Spatio-temporal Systems

Application Category

• Graph Algorithms and Modeling for the Web: Querying, indexing, and retrieval in Web-related graphs
• Economics, Online Markets and Human Computation: Data quality aspects of human-annotated datasets
• Search and Retrieval-Augmented AI: Efficiency and scalability of Web search engines

Abstract

We introduce a new dataset and algorithm for fast and efficient coastal distance calculations from Anywhere on Earth (AoE). Existing global coastal datasets are only available at coarse resolution (e.g. 1-4 km) which limits their utility. Publicly available satellite imagery combined with computer vision enable much higher precision. We provide a global coastline dataset at 10 meter resolution, a 100+ fold improvement in precision over existing data. To handle the computational challenge of querying at such an increased scale, we introduce a new library: Layered Iterative Geospatial Hierarchical Terrain-Oriented Unified Search Engine (Lighthouse). Lighthouse is both exceptionally fast and resource-efficient, requiring only 1 CPU and 2 GB of RAM to achieve millisecond online inference, making it well suited for real-time applications in resource-constrained environments.

Problem

• High-precision global coastline distance calculations
• Efficient computation for real-time applications
• Overcoming coarse resolution in existing datasets

Innovation

• 10m resolution global coastline dataset
• Lighthouse library for fast queries
• Millisecond inference with low resources