Radio Interferometry Image Reconstruction Lab

Every dramatic scientific image built from a radio-telescope array — most famously the Event Horizon Telescope's picture of a black hole's shadow — is not a photograph but a mathematical reconstruction from sparse Fourier-plane measurements. This lab simulates a small interferometric array: as Earth rotates, each antenna pair sweeps an elliptical track through the uv (spatial-frequency) plane, visibility samples accumulate live, and a dirty beam and dirty image form from that incomplete coverage. Once synthesis completes, the Högbom CLEAN algorithm runs iteratively in view, subtracting scaled copies of the dirty beam from the brightest residual peaks until a sharp reconstruction of the true sky — a black-hole-shadow-like ring with an asymmetric bright knot — emerges from the noise.