Developer Builds FastAPI Backend Serving Live Sentinel-2 Imagery and Orbital Data

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A developer has built a full-stack application that displays the Sheffield Cholera Monument from two perspectives simultaneously: satellite-based vegetation data from space and a centimeter-scale 3D ground model. The backend is a FastAPI service that authenticates with the Copernicus Sentinel Hub via OAuth2 to fetch the latest Sentinel-2 satellite imagery over a defined geographic area. It computes NDVI vegetation indices and uses Two-Line Element data with the Skyfield and SGP4 libraries to calculate the satellite's exact orbital position during each image acquisition. Four API endpoints — covering the latest scene, NDVI imagery, NDVI statistics, and orbital position — are designed to remain stable even if upstream data sources become unavailable. The project demonstrates how combining orbital and ground-level observation scales on a single CesiumJS 3D globe can reveal complementary insights about the same location.

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