What does a Gaussian-clutter radar simulator do to a CFAR detector's false-alarm rate?
research/radar-clutter-twin
What a Gaussian-clutter radar twin does to a CA-CFAR detector: exact false-alarm law under gamma texture (matched to simulation), 9–30× inflation at design 1e-4, 1.9–3.7 dB threshold repair, shared texture is harmless, and a real-cell calibration budget (median 1.1× at 1000 cells).
What it found
A CA-CFAR threshold set in a Gaussian-clutter twin and deployed in gamma-textured (K-distributed) clutter has an exact false-alarm law, matched to direct simulation to ~1%. At design 10−4 the real rate is 9× (ν=5) to 30× (ν=2) too high, and 50× to 358× at 10−6; restoring it costs 1.9–3.7 dB of threshold at 10−4. If texture is shared across the window CFAR is unaffected, so the twin must model spatial correlation. A moment fit of ν from 1000 real clutter cells brings the median to 1.1× (90th percentile 2×), versus ~106 cells to threshold empirically. Stylised: no target, no measured data.
A figure from its own output
Paper, code and results
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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.