New Developer Tool Tracks Every Satellite That Passed Over Any Location in a Week

A developer has launched a new web-based tool designed to show users every satellite that has passed over a specific geographic location within the past seven days, complete with corresponding satellite imagery. Built out of curiosity regarding which spacecraft might have photographed a residential street, the application allows users to type in any location and instantly retrieve pass data.

The underlying technology performs calculations in the browser in roughly half a second, utilizing the SGP4 propagation model against the CelesTrak catalog. It then retrieves actual imagery from Sentinel-2, Landsat, and NASA archives. To handle the immense visual data, approximately 17,000 objects currently in orbit are rendered in real-time on the GPU, solving Kepler s equation for every single frame.

Developer reflections on the project note several interesting engineering hurdles, such as accounting for Sentinel-2 timestamps that occasionally differ by five to ten minutes from the exact moment a satellite crosses a given coordinate. The creator emphasizes privacy by design, noting that the application only displays a ‘watched’ status if a legitimate image exists and does not store user location data. The source code has been published on GitHub for community feedback and future enhancements.

Aggregated summary. Original: Hacker News