Estimating the speed of the ISS using computer vision (Python + OpenCV)

Estimating the speed of the ISS using computer vision I recently revisited an older project I built with a friend for a school project as part of the ESA Astro Pi 2024 challenge. The idea was simple: estimate the speed of the ISS using only images of Earth. Approach The project is written in Python using OpenCV. The pipeline looks like this: capture two images detect keypoints using SIFT match them using FLANN measure pixel displacement convert that into real-world distance (GSD) calculate speed based on time difference Result Estimated speed: ~7.47 km/s Actual ISS speed: ~7.66 km/s So roughly a 2–3% difference. Not perfect, but surprisingly close considering it’s based purely on image analysis. Limitations The original runtime images are unfortunately lost, so the repository mainly contains test/template images. This obviously limits how well the results can be reproduced. What I would improve Looking at it now, I would: improve filtering of bad matches make the pipeline cleaner handl